The Eco-Efficient Design of Small Photovoltaic …...School of Design Master of Science in Design and Engineering The Eco-Efficient Design of Small Photovoltaic System A Handbook of

School of DesignMaster of Science in Design and Engineering

The Eco-Efficient Design of Small Photovoltaic SystemA Handbook of Life Cycle Design Guidelines for Small Photovoltaic System

2015-2016

Student: Marco Grazia 833552

Tutor:Prof. Carlo Arnaldo Vezzoli

Co-Tutor:Dr. Carlo ProserpioDr. Emanuela Delfino

3

A small photovoltaic system usually produces a quantity of energy to satisfy the daily requirement of an average family. The most common installation is on the home rooftop, where the system is able to capture sunlight in the best way and convert it into electricity to be used immediately.

This technology, nowadays, it is identified as a low environmental impact, even if the production efficiency is still be low. However, it is important to assess all aspects of its life cycle stages (LCA) to truly understand the overall possible adverse effect it has on the environment. This assessment should result in identifying areas of priority when designing future eco-efficient small photovoltaic systems.

The environmental assessment on the phases helps us to identify the real environmental impact. The individual stages of the life cycle include: pre-production, production, transportation, use and disposal.

This thesis performs a Life Cycle Assessment (LCA) on a typical small photovoltaic system, and identifies environmental priorities over the Life Cycle Design (LCD) strategies and guidelines. In other words this thesis moves from general to product specific LCD guidelines and a checklist. All of this will result in the form of a handbook for designer free of charge and in copy left.

Abstract ENG

5

Un piccolo impianto fotovoltaico solitamente produce una quantità di energia volta a soddisfare il fabbisogno giornaliero di una famiglia di medie dimensioni. L’installazione più comune è quella sopra il tetto della propria abitazione dove l’impianto riesce al meglio a catturare la luce del sole e a trasformarla in energia elettrica da utilizzare nell’immediato.

Oggi, questa tecnologia, viene identificata a basso impatto ambientale, anche se l’efficienza di produzione risulta essere ancora molto bassa. Esistono una serie di accorgimenti che possono servire per valutarne appieno il ciclo di vita del prodotto (LCA) e l’impatto ambientale. Ciò aiuta ad indentificare le priorità ambientali nell’ambito della progettazione e, conseguentemente, l’incremento di eco-efficienza in questo genere di prodotto.

La valutazione ambientale sulle fasi ci aiuta ad identificare il reale impatto ambientale. Le singole fasi del ciclo di vita comprendono: pre-produzione, produzione, trasporto, uso e dismissione.

Questa tesi sviluppa la valutazione del ciclo vita (LCA) di un piccolo impianto fotovoltaico, e ne identifica le priorità strategiche ambientali andando a sviluppare le linee guida di progettazione del ciclo vita (LCD) specifiche per il tipo di prodotto e indicatori di priorità strategiche ambientali. Il risultato finale della ricerca progettuale è un manuale di linee guida per la progettazione di piccoli impianti fotovoltaici, disponibile in licenza craetive commons e disponibile gratuitamente nella versione digitale.

Abstract ITA

8

Abstract ENGAbstract ITA

1. Background1.1 Introduction1.2 Who Can Benefit from Life Cycle Design?1.3 What is Life Cycle Design?1.4 Sustainable Energy for All1.5 The Context of Photovoltaic in the World

2. The Design Research2.1 Overview2.2 Product Life Cycle2.3 Functional Unit2.4 Life Cycle Phases2.5 Life Cycle Design Guidelines

3. The Studied Photovoltaic System3.1 The Context of Photovoltaic in Italy3.2 The Photovoltaic Technology3.3 Types of Photovoltaic Systems3.4 Photovoltaic System Components

3.4.1 The Solar Cell3.4.2 The Photovoltaic Module3.4.3 The Inverter3.4.4 The Support Structure3.4.5 The Electric Installation

4. The LCA of PV System4.1 The Life Cycle Assessment (LCA)4.2 The SimaPro Software4.3 Phase I: Goal and Scope Definition

0305

131416171819

232425272831

35363840424244464747

49505253

9

4.3.1 The System Under Study4.3.2 Data Collection and Quality4.3.3 The System Boundaries

4.4 Phase II: Life Cycle Inventory (LCI)4.4.1 The Functional Unit4.4.2 Photovoltaic Module Inventory4.4.3 Inverter Inventory4.4.4 Support Structure Inventory4.4.5 Electric Installation Inventory

4.5 Phase III: Life Cycle Impact Assessment (LCIA)4.6 Phase IV: Interpretation

5. Priorities for Environmental Impact Reduction5.1 PV System Life Cycle Guidelines and Priorities5.2 Minimise Materials Consumption

5.2.1 PV Module5.2.2 Inverter5.2.3 Support Structure5.2.4 Electric Installation

5.3 Optimisation of Product Lifespan5.3.1 PV Module5.3.2 Inverter5.3.3 Support Structure5.3.4 Electric Installation

5.4 Minimising Toxic Emissions5.4.1 PV Module5.4.2 Inverter5.4.3 Support Structure5.4.4 Electric Installation

5.5 Improve Lifespan of Materials5.5.1 PV Module5.5.2 Inverter5.5.3 Support Structure

5354545656586062636466

69707881848790929599103107110113115117119120123127131

10

5.5.4 Electric Installation5.6 Minimising Energy Consumption

5.6.1 PV Module5.6.2 Inverter5.6.3 Support Structure5.6.4 Electric Installation

5.7 Renewable and Bio-Compatible Resources5.7.1 PV Module5.7.2 Inverter5.7.3 Support Structure5.7.4 Electric Installation

5.8 Design for Disassembly 5.8.1 PV System

6. Checklist

7. Conclusion7.1 Future Steps7.2 Final Remarks7.3 Acknowledgments

8. References8.1 Bibliography8.2 Sitography8.3 Image Sources

135137138140142144146149151153155156157

161

251252253255

257258261263

14

A photovoltaic (PV) system is a technology that converts the energy from sunlight into electrical energy. In particular, this thesis, is focused on small photovoltaic system, which usually meet the need of a sandard family composed by 3 or 4 people.

Photovoltaic power generation is considered a renewable energy source because it does not consume exhaustible materials or fuel during energy production. Actually after the construction phase it uses no materials during energy generation, and the resources used, the sunlight, is infinity and widely distributed across the planet.

While for a large PV system it needs large space for the construction, a small PV system can be mounted on the house roof and it can be connected with the electricity network (grid-connected) or not (stand-alone). Since small PV system usually haven’t a lot of components, they are seen as having a relatively low environmental impact compared to large PV system that take up large areas. Anyway the PV system designer and site developer must strike a balance to maintain both the health of the location (for example visual impact) and the economic gains.

The European Directive regarding renewable energy imposed that a specific proportion of energy be produced from renewable sources to all the member states. This consequentially has increased the investment in the renewable sectors making sustainable energy resources a priority.

But it’s important to say that, actually, if by green energy we understand 0 emission outputs, no product is 100%

1.1 Introduction

15

emission free. This is due to the fact that in order to produce any product an exchange of substances need to happen between the biosphere, the geosphere and the technosphere. This means that any product has an environmental impact that can be measured, due to the fact that it needs to be pre-produced, produced, transported, used and disposed of at the end of its lifespan.

Fig.1.1 - Detail of a photovoltaic system

16

The design criteria and generation guidelines are useful for engineers and designers to know the possible environmental impacts from the earliest stages of the project, in order to achieve energy and environmental eco-efficiency through assessments and environmental reduction guidelines. PV systems are generally designed by specialized companies with design teams usually consisting of electronic and mechanical engineers. The typical user could be range over from a large company, to a single user with a low energy consumption. This create several scenarios, including the possibility of installing PV devices in underdeveloped countries like Third World, which it is very interesting for future developments of this technology.

Anyway, some people have argued that PV system have an high cost and the efficiency is not so good as traditional fuels. This makes Life Cycle Design strategies more and more mandatory stages during PV system design, to know what is the best choice.

1.2 Who Can Benefit from Life Cycle Design?

17

The first criteria of Life Cycle Design (LCD) is to change the focus from classic phisical product design to designing stages of the product life cycle. All activities related to the product, from the production of materials to its distribution, its use and finally its disposal, are considered as a single unit. The second criteria of LCD is to design with regard to the function delivered by the product. In fact, it is in relation to this function (functional unit) that it is possible with Life Cycle Assessment (LCA) to assess whether the environmental impact has been reduced and how.

A life cycle model that comprises all the life cycle stages of the product is made, starting from extraction of material until their disposal. The functional unit is considered to be the availability of the PV system to create renwable energy for a period of 25 years. Further an environmental assessment is made on this model, in order to understand the environmental impact of each of the life cycle stages, for the main components of the system.

Next, the priority indicators for product specific guidelines are calculated using IPSA (Strategic Design Priorities Identification) method. The result is a rank list of seven most important LCD strategies. The rank and the guidelines are as follows:1. Minimise Materials Consumption;2. Minimising Energy Consumption;3. Minimising Toxic Emissions;4. Renewable and Bio-Compatible Resources;5. Optimisation of Product Lifespan;6. Improve Lifespan of Materials;7. Design for Disassembly.

1.3 What is Life Cycle Design?

18

1.4 Sustainable Energy for All

Energy is essential to answer to basic human necessities, and it is also necessary to sustain economic activities. Having energy is in fact a necessity to promote growth and economic wellness; this is why energy has become a major geopolitical and socio-economic issues. Furthermore the energy sector has a large environmental impact on the Earth. The world population will continue to grow, at least for some years, this means that also the energy requirement is going to increase. The focus is how the reliable source of electricity is going to be produced. Nowadays, worldwide, 68% comes from fossil fuels, 13% from nuclear fission and 19% from renewable resources.

All energy sources have starting financial and environmental costs, but fossil energy is by far the most used source of energy worldwide and the resources are limited, as this resources become less abundant, the price will increase. Furthermore fossil energy use is associated with a number of negative environmental effects is likely to contribute to global climate change, but also gives rise to other negative impacts.

To provide well-being and meet energy security, there is the need to reduce the use of fossil energy resources: clean energy should be enhanced.

19

Worldwide growth of photovoltaic has been fitting an exponential curve for more than two decades: during this period of time it has evolved from a small market towards becoming a mainstream electricity source. When solar PV systems were first recognized as a hopeful renewable energy technology, programs were implemented by a number of governments in order to provide economic incentives for investments. As a consequence, cost of solar declined significantly due to improvements in technology and economies of scale.

Historically, the United States had been the leader of installed photovoltaic for many years, and its total capacity amounted to 77 MW in 1996. Then, Japan stayed ahead as the world’s leader of produced solar electricity until 2005, when Germany took the lead. In 2016 China became world’s largest producer of photovoltaic power and is expected to continue its rapid growth and to triple its capacity to 70 GW by 2017.

In 2014, Asia was the fastest growing region, with more than 60% of global installations. Europe continued to decline and installed 7 GW or 18% of the global photovoltaic market. For the first time, North and South America combined accounted for at least as much as Europe. This is due to the strong growth in the United States, supported by Canada, Chile and Mexico.

In terms of cumulative capacity, Europe is still the most developed region with 88 GW or half of the global total of 178 GW. Photovoltaics now covers 3,5% and 7% of European electricity demand and peak electricity demand, respectively. The Asia-Pacific region (APAC) which includes

1.5 The Context of Photovoltaic in the World

20

countries such as Japan, India and Australia, follows second and accounts for about 20% percent of worldwide capacity. In third position ranks China with 16%, followed by the Americas with about 12%. Cumulative capacity in the MEA (Middle East and Africa) region accounted for only about 3,3% of the global total. A great untapped potential remains for many of these countries, especially in the Sunbelt.

An interesting consideration is about the PV module price. In fact from 2008 to 2012, prices were divided by five, and PV system prices divided by three in mature markets. In 2013 and 2014, module prices more or less stabilised, indicating that prices were not fully reflecting underlying costs. As too many modules began to be produced, many were sold at prices too low to recover investment, as the deterioration of the balance sheets of most companies demonstrated. But improvements in technology and the scaling up of manufacturing were by far the main factors driving cost reductions. Production of PV modules in China has stimulated competition and reduced prices.

In 2014, the International Energy Agency (IEA) released its latest edition of the Technology Roadmap: Solar Photovoltaic Energy report. The IEA also admitted to have previously underestimated photovoltaic deployment and reassessed its short-term and long-term goals.

For 2020, conservative scenarios forecast capacity to reach 400 GW, assuming declining annual installations from current levels, while more optimistic scenarios project cumulative capacity to grow beyond 500 GW. Only the most optimistic projections around 600 GW foresee annual installations to grow above 10% in the near future.

21

IEA’s long-term scenario for 2050 describes worldwide photovoltaic capacity to reach 4.600 GW. In order to achieve IEA’s projection, PV deployment of 124 GW and investments of $225 billion are required annually. This is about three and two times of current levels, respectively.

Fig.1.5 - Cumulative capacity in MW grouped by region

24

Assessing environmental requirement for industrial products became available as a discipline in the second half of 1990s and was able to deal with the complexity of the subject. This discipline was able to evaluate the environmental impact of the input – output between the technosphere of a product and the geosphere and the biosphere.

In more general terms is the exchange of substances between the nature and the production-consumption system:• As inputs: extracting substances from the environment

(extracting resources, alteration of ecosystem’s balance)• As outputs: emitting substances into the environment

(extraction processes)

There are two approaches, which have great enough repercussion on design approaches that aim to integrate environmental requirement into industrial products. Those are: product life cycle, and functional unit.

2.1 Overview

25

Product life cycle refers to a holistic approach on all the stages of the life of the product, starting with the mining for necessary resources and manufacturing its components to energy and resources and emissions flows during the use, to the end-of-life treatments.

The entire life of a product can be described as a set of activities and processes, while every one of them consume a certain amount of resources and energy goes through a series of transformations and emissions of various kinds.

To help trace the life cycle of a product the processes are divided into the following phases:

1. Pre-Production• Acquisition of resources• Their delivery to the production area • Their transformation into raw materials or energyRaw materials and energy are produced from:• Primary or virgin resources• Secondary or recycled resourcesPrimary resources come straight from the geosphere and can be classified as:• Renewable primary resources• Non- renewable primary resources

2. Production• Processing of materials• Assembly• Completion

2.2 Product Life Cycle

26

3. Distribution• Packaging• Transportation• Storing

4. Use• Utilization or consumption• Service

5. DisposalOptions:• It is possible to restore the functionality of the product or

its parts (reusing or re-manufacturing)• It is possible to recover the component materials and

energy of the disposed product (recycling, composting, incineration)

- Open loop recycling - Closed loop recycling (inside the same production system)

In any of this cases recycling implies a series of processes and stages:

- Recollection- Transportation- PP of secondary raw materials / incineration

• After all this, is possible to regain nothing (landfilling)

27

The functional unit is the impact of a sum of cumulated processes employed to satisfy a certain function, and not the independent product impact on the environment.

In the case of this thesis, the functional unit is to satisfy the need of electricity of a standard family and not the physical characteristics of the construction. In other words, the functional unit is a performance of the assessed PV system; for this reason the function and the service supplied by the product has to be studied, not just the physical product itself.

The functional unit starts to be important when we need to match equivalent products, services or processes, therefore it becomes the measure for comparison amount products with a similar function.

Consequently the second fundamental parameter is based on designing the function that the product has to supply rather than the other product.

2.3 Functional Unit

28

2.4 Life Cycle Phases

Life cycle design is also called “eco-design” or “design for the environment” and it supplies to develop a product considering not only the product itself, but all the phases of its life cycle, from the production of materials to its distribution, to its use and finally its disposal, considering it as a single unit.

One important rule of LCD is to design with regard to the product function delivered by the product, more than from the physical product itself. In fact, it is in relation to this function (functional unit) that it is possible to assess whether the environmental impact has been reduced and how.

This method is a product system design, where all life stages and all the events in the product lifespan are taken into account. In this way the designer can identify of all the consequences of the designed product.

The disadvantages are relating to the complex process: in fact it needs a lot of informations about the input-output processes and their impact on nature. In addition it’s difficult evaluate the techno-economical evolution to disposal. Not everything is known during the design process: those processes are always in evolution and hard to predict with any certainty. So the designer cannot be the only responsible of the entire product system, other participants need to take over or control the stages of the life cycle.

The LCD should try to minimise the environmental impact at all stages, even though the production system is totally or partially controlled by the producer or designer from inside a company.

29

Areas where a LCD designer has good control:

Pre-production• acquiring materials with a lower environmental impact• choose raw materials that use renewable sources for

exploitation or pre-production• choose secondary or recycled materials

Production• choose raw materials that do not need a lot of processing• employ procedures with low impact for construction and

assembly of the station, on site and before

Distribution• choose nearby suppliers• choose transportation with low environmental impact• choose materials that are not packed

Use• choose renewable energy sources

Disposal• choose easily recyclable materials with accurate lifespan

Areas where a LCD designer has partial control:

Pre-production• controlling the processes or energy sources used during

exploitation of raw materials• transportation of raw materials from the geosphere to

raw manufacturing factories• controlling the processes or energy sources used during

pre-production of raw materials

30

• finding information about processes of secondary raw material

• exact emissions and energy used for pre-production• finding information about the chain of delivery from

exploitation to acquisition company

Production• exact emissions and energy used for production• environmental impact on site of the construction

Distribution• finding suppliers that use local materials

Use• efficiency of energy distribution lines• efficiency of maintenance works

Disposal• disassembly procedures• disposal transport• amount of recycled materials• amount of materials to landfill• environmental impact of disposed materials

31

1 Dahlstrom H. (1999) Company-specific guidelines. J. Sustain Product Design

2.5 Life Cycle Design Guidelines

Usually, the term “guideline” is used to suggest a group of procedures and tools to orient a decision making process towards given objectives.

The guidelines for LCD can be defined as support tools for the design process of product conceptualisation and development.

The guidelines inspire and indicate those design decisions/solutions that have the major potential to be environmentally sustainable. They should also give a direction to achieve environmental gains in the product that has to be designed, anyway, this doesn’t always happen. Moreover, it is important to know that guidelines are not fixed, but can evolve in time with the knowledge updating.

The term environmental design criteria, as a concept for guidelines management and aggregation, should represent a separated area of concern of environmental sustainability in a form that is understandable by a designer, should allow some kind of environmental assessments, in terms of relative environmental priority setting and should allow the clustering of guidelines.

Guidelines have to inspire and indicate, as precisely as possible, those design decisions that have the greater potential to be sustainable: they should “provide specific advice and strategies on how to reduce impacts” (Dahlstrom H)1.

The specificity of guidelines refers to the quality of the decision making process and the product typology. Important is that for any decision making process, there should be

32

a specific set of guidelines considering what has to be decided and by whom. Guidelines’ specificity per product typology refers to its general requirements, characteristics and functionality and to its typical environmental impact.

Given the variability of the environmental impacts for the various product typologies, guidelines/criteria may have an environmental weight: some guidelines/criteria would be more relevant than others.

So it is important to decide guideline priorities per any product typology: they should be defined on the basis of a more critical environmental impact for the product typology according to the potentials of environmental impact reduction for a series of determined criteria. Besides, the elaboration of specific guidelines, it is important to define an effective process aiming at their integration into company realities. Then the problem of the usability of the guidelines acquires two main purposes: the first one is referred to the integration in the company’s existing procedures; the second one is related to the staff which makes use of them: human beings with their own habits and expectations.

36

3.1 The Context of Photovoltaic in Italy

Photovoltaic in Italy has been grown quickly in recent years becoming one of the largest producers of electricity from solar power in the world.

The sector provides employment to about 100.000 people, especially in design and installation: as of the end of 2010, there were 156.000 solar PV plants, with a total capacity of 3,5 GW. At the end of 2011, there were 330.200 installations, totaling 13 GW. The number of plants and the total capacity surged between 2009 and 2011 following high incentives from Conto Energia. The total power capacity installed tripled and plants installed doubled in 2010 compared to 2009, with an increase of plant’s average dimensions. The increase was even greater in 2011. Installed photovoltaic capacity has increased nearly fifteen times from 2009 to 2013. PV systems in 2015 generated 24,7 GWh of electricity, covering 7,8% of the country’s electricity mix, according to Terna, Italy’s electricity transmission grid operator.

The annual energy production from photovoltaic in Italy ranges from 1.000 to 1.500 kWh per installed kWp. A 2013 report by Deutsche Bank concluded that solar power has already reached grid parity in Italy.

Italy appears to be one of the largest producers of this kind of energy thanks to its strategic position at the center of the Mediterranean. It is in fact a typical southern Europe reality in which there is a good radiation available all year round.

The system that I’m going to study arises in a strategic location for the production of electricity. In fact, it is located in northern Italy, more precisely in Emilia-Romagna, near the city of Bologna, where there is a large production of

37

Fig. 3.1 - Regional photovoltaic power distribution in Italy

energy from this kind of plants. The system is in a raised position on the rooftop of a private home. Here there aren’t any disturbing elements that could affect the optimal energy production.

38

Photovoltaic effect is the process in which two dissimilar materials in close contact produce an electrical voltage when struck by light. This striking crystals such as silicon, in which electrons are usually not free to move from atom to atom within the crystal, provides the energy needed to free some electrons from their bound condition. Free electrons cross the junction between two dissimilar crystals more easily in one direction than in the other, giving one side of the junction a negative charge and, therefore, a negative voltage with respect to the other side, just as one electrode of a battery has a negative voltage with respect to the other. The photovoltaic effect can continue to provide voltage and current as long as light continues to fall on the two materials.

The technology of photovoltaic has long proven to be something that really works. The seemingly complicated process of converting solar radiation into electric current is an easily replicable, sustainable way of generating electricity to power our modern world. Like any other kind of technology available for mankind to use, there are pros and cons to photovoltaic.

One of the most important features of solar power is that it is renewable and derived from sunlight, that is abundant around the planet. Another pro of PV system is that it does not emit pollution while generating power and it is also fare well in terms of longevity: studies and tests show that photovoltaic installations can be operated for a century. Finally, operating expenses are kept low and panels are totally silent, producing no noise at all: they are a perfect solution for urban areas and for residential applications.

3.2 The Photovoltaic Technology

39

This technology also has some disadvantages: it depends entirely from the sunlight and, in the absence of it for various reasons (during night or in a cloudy day), it becomes impossible to produce electricity. Another problem arises if you want to store the energy in batteries: they will need maintenance and intervention during the course of operation, and some replacements during the PV system lifespan. Finally, PV modules efficiency levels are relatively low (between 10%-20%) compared to the efficiency levels of other renewable energy systems.

Anyway, thanks to its good features and thanks to the important investments that nations all over the world are making on this technology, photovoltaic is destined to capture a leading position in the short term future.

40

PV systems are generally classified according to how the equipment is connected to the other power sources and electrical loads. There are two different types of systems: grid-connected or stand-alone.

Grid-connected systems use an inverter that converts the energy collected from the PV modules into conventional AC power and feeds it to your electrical circuit breaker panel. As long as there is enough electricity flowing in from the PV system, no electricity will flow in from the utility company. If the system is generating more power than it is used, the excess will flow back into the grid. Grid-connected system is the simplest and most cost effective way to connect PV modules to regular utility power. It can supply solar power to the home and use utility power as a backup. If utility power is reliable and well maintained in your area, and energy storage is not a priority, you don’t necessarily need a battery.

Far less common is the stand-alone system, which produces and stores power independently from the utility grid. These systems are particularly suitable in remote locations. The electricity generated by the PV modules is stored in a bank of rechargeable batteries as DC but in order to power household appliances an inverter will be required to convert the stored DC to AC. These rechargeable batteries contain specialised parts and chemicals not found in disposable batteries and are therefore larger and more expensive to purchase and maintain. There is also a charge controller that is the protection device to prevent the excess of battery charges and interrupt the photovoltaic field when the battery is charged.

3.3 Types of Photovoltaic Systems

41

Fig. 3.3a, 3.3b - Differences between grid-connected and stand-alone PV systems.

Grid-Connected

Stand-Alone

42

PV systems are made up of interconnected components, each with a specific function. One of the major strengths is modularity: as your needs grow, individual components can be replaced or added to provide increased capacity. The selected components will vary depending on the applications, what follows is a brief overview of the components of a typical grid-connected PV system.

3.4.1 The Solar CellSolar cells are the power units of every PV system. A cell consists of two thin layers of semi-conducting materials, usually silicon, that have been treated with chemical substances. These chemicals react to sunlight when it shines on the cell, creating an electric field across the layers and producing electricity. The greater the intensity of sunlight, the greater the flow of electricity thanks to the PV effect.

Here is an overview as to the properties of the most common types of commercial solar cell available today.

• Monocrystalline silicon are made using cells sliced from a single cylindrical crystal of silicon. This is the most efficient PV technology, typically converting around 15-18% of the sun’s energy into electricity. The manufacturing process required to produce monocrystalline silicon is complicated, resulting in slightly higher costs than other technologies.

• Polycrystalline silicon cells are made from cells cut from an ingot of melted and recrystallized silicon. The ingots are then saw-cut into very thin wafers and assembled into complete cells. They are generally cheaper to

3.4 Photovoltaic System Components

43

Fig. 3.4.1 - Schematic view of the solar cell

produce than monocrystalline cells, due to the simpler manufacturing process, but they tend to be slightly less efficient, with average efficiencies of around 11-14%.

• Amorphous silicon cells are made by depositing silicon in a thin homogenous layer onto a substrate rather than creating a rigid crystal structure. As amorphous silicon absorbs light more effectively than crystalline silicon, the cells can be thinner - hence its alternative name of ‘thin film’ photovoltaic. Amorphous silicon can be deposited on a wide range of substrates, both rigid and flexible, which makes it ideal for curved surfaces or bonding directly onto roofing materials. This technology is, however, less efficient than crystalline silicon, with typical efficiencies of around 5-10%, but it tends to be easier and cheaper to produce.

44

Fig. 3.4.2a - Sandwich of PV module

3.4.2 The Photovoltaic ModuleCells are connected electrically in series and/or parallel circuits to produce higher voltages, currents and power levels. Modules consist of cells circuits sealed in an environmentally protective laminate, and are the fundamental building blocks of PV systems. String include one or more modules assembled as a pre-wired, field-installable unit. An array is the complete power-generating unit, consisting of any number of modules and strings. The performance of modules and arrays are generally rated according to their maximum DC power output (watts) under Standard Test Conditions (STC), that are defined by a module operating temperature of 25°C, and incident solar irradiance level of 1000 W/m2 and under Air Mass 1,5 spectral distribution. Since these conditions are not always typical of how modules and arrays operate in the field, actual performance is usually 80-90% of the STC rating. In the following page you can find the main losses of a PV system.

45

Fig. 3.4.2b - PV module production phases

PV system losses are usually caused by:• Temperature (2-4%): with increasing temperatures,

conversion losses increase. These losses depend on irradiance, mounting method (glass, thermal properties of materials), and wind speeds.

• Reflection (2-3%): reflection losses increase with the angle of incidence. Also, this effect is less pronounced in locations with a large proportion of diffuse light.

• Dirt (1-2%): losses due to dirt are up to 3% in temperate regions with some frequent rain and up to 15% in arid regions with only seasonal rain and dust.

• Shadows (0-3%): shadows may be caused by trees, chimneys etc. Depending on the stringing of the cells, partial shading may have a significant effect.

• Snow (0-3%): dependant on location and maintenance effort.

• Conversion (1-2%): the nominal efficiency is given by the manufacturer for standard conditions.

• Wiring (0-3%): any cables have some resistance and therefore more losses.

• Inverter (2-10%): depends from the inverter efficiency.

46

Fig. 3.4.3 - A typical inverter for domestic use

3.4.3 The InverterThe inverter is utilized to transmit the energy produced by the PV system to the national power grid: in fact, it converts low voltage DC into higher voltage AC. Electricity transmits more efficiently at higher voltages and it’s the standard used worldwide. Inverters are available in a wide range of wattage capabilities. Early inverters produced a square wave alternating current which at times resulted in problems while operating with solid-state equipment. Now, modern inverters produce a modified sine wave which takes care of most of the problems that square-wave inverters had. Modified sine wave is not quite the same as power company electricity. They are lower cost, very efficient and most appliances will accept it although there are some notable exceptions.

47

Fig. 3.4.4 - Support structure mounted on the rooftop

3.4.4 The Support StructureThe support structure allows to fix the PV modules on every kind of surfaces and, with appropriate substructure, you can realize fittings: integrated, partially integrated or not integrated. The assembly of PV system is a simple operation that involves the laying of the single module on two line of aluminium bars and locking it with clamps. The support structures are guaranteed against snow loads and wind, and have a high resistance to corrosion due to weathering even after many years.

3.4.5 The Electric InstallationEach grid-connected PV system is composed by many PV modules, the inverter, the support structure and, finally, by the electric installation. This consists of electric cables and components that are fundamental to link all parts each other and connect the PV system with the national power grid to allow the right production of energy.

50

The Life Cycle Assessment is the method of quantifying and estimating the environmental impact and it is made with the use of the SimaPro software. The product LCA had official identification in international standards as it was introduced to the International Standard Organization normative as ISO 14040.

According to the ISO 14040 definition, the LCA technique addresses the environmental aspects and potential environmental impacts throughout a product’s life cycle from raw material acquisition through production, use, end-of-life treatment, recycling and final disposal, that is: compiling and inventorying the implications of the system’s inputs and outputs; evaluation of potential impacts regarding these inputs and outputs; interpreting the results of the inventory and evaluation phases according to given scope and objectives.

There are four phases in an LCA study:1. The goal and scope, including the system boundary and

level of detail, of an LCA depends on the subject and the intended use of the study.

2. The Life Cycle Inventory (LCI) analysis phase is the second phase of LCA. It is an inventory of input/output data with regard to the system being studied. It involves collection of the data necessary to meet the goals of the defined study.

3. The Life Cycle Impact Assessment phase (LCIA) is the third phase of the LCA. The purpose of LCIA is to provide additional information to help assess a product system’s LCI results so as to better understand their environmental significance.

4.1 The Life Cycle Assessment (LCA)

51

4. Life cycle interpretation is the final phase of the LCA procedure, in which the results of a LCI or an LCIA, or both, are summarized and discussed as a basis for conclusions, recommendations and decision-making in accordance with the goal and scope definition.

LCA is one of several environmental management techniques and might not be the most appropriate technique to use in all situations. LCA typically does not address the economic or social aspects of a product, but the life cycle approach and methodologies can be applied to these other aspects.

However, to estimate and understand relations between the product and the environment can be complicated, in fact the sum of processes that go into the life cycle of the product can be hard to pin point in detail, which is why a life cycle model is required, from the extraction of raw materials to the disposal processes, Anyway this model can rise considerable uncertainties. Even when the entire life cycle is mapped, despite of great progress, many impacts of processes remain doubtful. And also after we managed to reach a great understanding of the nature surrounding us, it is still a very complex model, and cause-effect relationships are arduous to isolate.

52

4.2 The SimaPro Software

SimaPro was developed in the ‘90s to facilitate the quantification of the environmental impact of a product’s life cycle. It was mainly developed to process LCA only and, after that, input-output tables were incorporated about a decade ago, enabling input-output analysis (IOA).

When using SimaPro an LCA model of a product, service, or system life cycle is created. What is important to realise is that a model is a simplification of a complex reality and as with all simplifications this means that the reality will be distorted in some way. The challenge for an LCA practitioner is to develop the model in such a way that the simplifications and distortions do not influence the results too much. The best way to deal with this problem is to carefully define the goal and scope of the LCA study.

Data related to all the life cycles phases are needed in order to create a faithful depiction of the environmental impacts.

SimaPro is using the Eco-indicator point as a measuring unit. The value of one 1pt is representative of one thousands of the yearly environmental load of one average European inhabitant. The absolute value of the points is not very relevant as the main point is to compare relative differences in the components.

53

4.3 Phase I: Goal and Scope Definition

The assessment of the system using SimaPro will generate Eco-indicator points that are used to calculate the environmental priorities. They are composed of some strategies that will help in generating precise and direct eco-efficient design guidelines for designing PV system with a lower environmental impact. The goal of the study is to create a handbook of guidelines and a checklist that will support and orientate the sustainable design based on this strategies:

• Minimise Materials Consumption;• Minimising Energy Consumption;• Minimising Toxic Emissions;• Renewable and Bio-Compatible Resources;• Optimisation of Product Lifespan;• Improve Lifespan of Materials;• Design for Disassembly.

The intended audiences for this guideline are engineers and designers of sustainability, the design guideline handbook will be free of charge and in copy left.

The scope of the study describes the most important methodological choices, assumptions, and limitations as described in the sections below.

4.3.1. The System Under StudyA PV system is an independent means of generating energy harnessing the power of sunlight. The system under consideration is located in the Emilia-Romagna region in Italy, near the city of Bologna, in the middle of Padan Plane.This grid-connected PV system is placed on the roof of a private house and is able to satisfy the needs of a family of

54

four people. It is oriented towards the south with a tilt angle of 30° and the total size, relative to the surface occupied by the panels, it is of 28,16 m2; which corresponds to a rated output of 3,96 kWp.

4.3.2. Data Collection and QualityDimension data and component specifications were acquires from the technical data sheets provided directly by the manufacturers, and from measurements made on the site. For this reason, we can consider this data exact and precisely. The data for the inventory phase was acquired from other scientific documents (that you can find in the bibliography) and from the Ecoinvent database on SimaPro.

For the LCA the components were analyzed independently in order to highlight the one with the highest environmental impact.

4.3.3. The System BoundariesPre-production (PP):Following the volumetric design, the details found in technical data sheets, the literature and the Ecoinvent database, a bill of quantities was made and the materials inventoried were added as pre-production in the life cycle phase of each of the components. Those are considerate raw and at plant.

Production (P):The materials processed were calculated considering the Ecoinvent database and the quantities resulted in the PP phases.

55

Distribution (DS):Distribution change a lot from component to component since this products are very different each others. The PV module is made in Europe (usually Germany or Italy) and requires less resources compared to the inverter, that usually comes from the East market (China or Taiwan). The other components are manufactured closer to the assembly factory. It’s important to specify that distances are approximate, in fact it’s almost impossible to know the precise distance covered, especially for product coming from far. This is the reason beacause I’ve used average distances for every component. In those distances I’ve included the route from production factory to distribution company and from that to assembly site.

Use (U):For the use phase, the PV system should not require any cleaning or maintenance, except for unforeseen circumstances. If the system is built in the right place, there is no large consumption of resources: for this reason I’ve calculated as use the common losses of PV modules and the inverter that cause inefficiency of the PV system.Anyway, it’s important to know that the inverter must be replaced at half life of the plant.

Disposal (D):Today a PV system is almost entirely recyclable; in fact the disposal was assumed on average, about 90% recycled and 10% landfilled (it changed a little bit from component to component).

56

4.4.1 The Functional UnitIn a LCA, each quantity of materials or processes is calculated according to the system’s referral functional unit. It is the base of comparisons among product performances.

The PV system that I analyzed is located on the roof of a house based in Bologna and is able to satisfy the needs of a family of four people. The system is oriented towards the south with a tilt angle of 30° and the total size, relative to the surface occupied by the panels, it is of 28,16 m2; which corresponds to a rated output of 3,96 kWp.

The functional unit is constituted by the energy produced in 25 years. Every year there is a decrease of 1%, therefore the energy produced during the entire plant life cycle is calculated as follows.

The energy produced in the first year is equal to:E = H ∙ ebos ∙ Pnom = [kWh/year]

Where: E = electric energy produced in the first year of life of expressed in [kWh/year]; H = irradiation [kWh/m2]; (Bologna annual average 1424)ebos = BOS efficiency (the module used has an efficiency of 14%)Pnom = nominal PV power [kWp]

Replacing:E = H ∙ ebos ∙ Pnom = 1.424 ∙ 0,86 ∙ 3,96 = 4.849,57 [kWh/year]

The energy produced during the 25 years of plant life which considers the 1% annual decrease on energy production

4.4 Phase II: Life Cycle Inventory (LCI)

57

becomes:

Etot = E ∙ ∑i=0 0,01i = E ∙ [(1-0,9925)/(1-0,99)] =

= 4.849,57 ∙ 22,21786 = 107.747 [kWh]

The analysis of the life cycle will be performed using this value of energy: 107.747 [kWh] = 107,75 [MWh]

In this case the functional unit is: the availability of the 3,96kWp PV system to produce electricity for 25 years of operative lifetime. The energy produced per year = 4.309,88 kWh, about 107.747 kWh/25years.

In order to understand the environmental impact of the materials and processes, distribution and energy used, the resulting quantities are divided by the functional unit. In this case the MWh was used due to rounding figures. Consequentially all the quantities in the inventory are divided by 107,75 MWh.

29

58

4.4.2 Photovoltaic Module InventoryModel: Suntech STP180-24/Ab-1 (1580x808mm = 1,28m2)System dimension: 1,28m2 x 22 modules = 28,16m2

On Eco-Invent: Photovoltaic panel, multi-Si, at plant/RER/ (1m2)

PP

PartsQuantity

one module

(1m2)

Quantity SPVS

(28,16m2)Unit

N. module per F.U.

Lifespan (years)

N. parts /lifespan

Quantity per F.U. (kg/MWh) Material In SimaPro

Photovoltaic cell 0,932 26,257 m2 1 25 1 26,257/107,75=0,244

Silicon [1] Photovoltaic cell, multi-Si, at plant/RER U

Frame 2,629 74,044 kg 1 25 1 0,687 Aluminium Aluminium alloy, AlMg3, at plant/RER U

Solar glass 10,079 283,825 kg 1 25 1 2,634 Glass Solar glass, low-iron, at regional storage/RER U

Top layer sheet 1,0017 28,208 kg 1 25 1 0,262 EVA Ethylvinylacetate, foil, at plant/RER U

Film 0,111 3,109 kg 1 25 1 0,029 PVC Polyvinylfluoride film, at plant/US U

Back foil 0,373 10,503 kg 1 25 1 0,098 PE Polyethylene terephthalate, granulate, amorphous, at plant/RER U

Ribbon for interconnection

0,113 3,173 kg 1 25 1 0,029 Copper Copper, at regional storage/RER U

Junction box 0,188 5,289 kg 1 25 1 0,049 Glass fibre Glass fibre reinforced plastic, polyamide, injection moulding, at plant/RER U

Kit to attach 0,122 3,434 kg 1 25 1 0,032 Silicone Silicone product, at plant/RER U

Kit to clean 0,013 0,365 kg 1 25 1 0,003 Acetone Acetone, liquid, at plant/RER U

All parts 21,286 599,414 kg 1 25 1 5,563 Water Tap water, at user/RER U

Packaging 1,0956 30,852 kg 1 25 1 0,286 Cardboard Corrugated board, mixed fibre, single wall, at plant/RER U

P

PartsQuantity

one module

(1m2)

Quantity SPVS

(28,16m2)Unit Quantity per F.U.

(kg/MWh) Processing In SimaPro

All parts 0,005 0,133 MWh 0,0012 Electricity Electricity, medium voltage, production UCTE, at grid/UCTE U

5,407 152,264 MJ 1,413 Natural gas Natural gas, burned in industrial furnace low-NOx >100kW/RER U

Ribbon for interconnection

0,113 3,173 kg 0,029 Wire drawing Wire drawing, copper/RER U

Solar glass 10,079 283,825 kg 2,634 Tempering Tempering, flat glass/RER U

59

DT

Means Transported quantity Distance kg*km kg*km / F.U. In SimaPro

Lorry 1068,473 kg 500km 534236 4958 Transport, lorry >16t, fleet avera-ge/RER U

Train 600km 641084 5950 Transport, freight, rail/RER U

U

ActivityQuantity

one module

(1m2)

Quantity SPVS

(28,16m2)Unit Quantity per F.U. (kWh) In SimaPro

Energy loss /year [2]

0,015 0,430 MWh 0,004 Electricity, PV, at 3kWp slanted-roof, multi-Si, panel, mounted/CH U

DMDestination/Treatments In SimaPro

Considerated on average: Recycled - 90%, Landfill – 10%.

[1] It is important to say that Photovoltaic Cell is not only composed by Silicon (that represents the maximum part) but also other materials used during pre-production and production phases as: Glue for Metals, Ammonia, Phosphoric Acid, Phosphoryl Chloride, Titanium Dioxide, Ethanol, Isopropanol, Silicone, Sodium Silicate, Calcium Chloride, Acetic Acid, Hydrochloric Acid, Hydrogen Fluoride, Nitric Acid, Sodium Hydroxide, Argon, Oxygen, Nitrogen, Tetrafluoroethylene, Polystyrene.

[2] 10% of energy is lost: 0,430 MWh per year

60

4.4.3 Inverter InventoryModel: PowerOne PVI4200-O-IT (4200W)On Ecoinvent: Inverter, 2500W, at plant/RER/I (2500W)

PP

Parts

Quantity one

module (2500W)

Quantity SPVS

(4200W)Unit

N. module per F.U.

Lifespan (years)

N. parts /lifespan


Casing 1,400 2,352 kg 1 25 2 2,352*2/107,75= 0,044

Aluminium Aluminium, production mix, cast alloy, at plant/RER U

Cables 5,510 9,257 kg 1 25 2 0,172 Copper Copper, at regional storage/RER U

0,010 0,017 kg 1 25 2 0,0003 SAN Styrene-acrylonitrile copolymer, SAN, at plant/RER U

0,010 0,017 kg 1 25 2 0,0003 PVC Polyvinylchloride, at regional storage/RER U

Screws and clamps

9,800 16,464 kg 1 25 2 0,306 Steel Steel, low-alloyed, at plant/RER U

0,237 0,398 kg 1 25 2 0,007 Copper, PC Connector, clamp connection, at plant/GLO U

Inductor 0,351 0,587 kg 1 25 2 0,011 Copper, PC Inductor, ring core choke type, at plant/GLO U

Integrated circuit 0,028 0,047 kg 1 25 2 0,0009 Various Integrated circuit, IC, logic type, at plant/GLO U

Transistor 0,038 0,064 kg 1 25 2 0,0012 Copper Transistor, wired, small size, through-hole mounting, at plant/GLO U

Diode 0,047 0,079 kg 1 25 2 0,0015 Copper, Glass, Iron

Diode, glass-, through-hole mounting, at plant/GLO U

Capacitor 0,341 0,573 kg 1 25 2 0,0106 Various Capacitor, film, through-hole mounting, at plant/GLO U

0,256 0,147 kg 1 25 2 0,0027 Various Capacitor, electrolyte type, > 2cm height, at plant/GLO U

0,023 0,039 kg 1 25 2 0,0007 Various Capacitor, Tantalum-, through-hole mounting, at plant/GLO U

Resistor 0,005 0,009 kg 1 25 2 0,0002 Various Resistor, metal film type, through-hole mounting, at plant/GLO U


Insulating 0,300 0,504 kg 1 25 2 0,009 PS Polystyrene foam slab, at plant/RER U

0,06 0,101 kg 1 25 2 0,002 PE Fleece, polyethylene, at plant/RER U

Printed wiring board

0,225 0,377 m2 1 25 2 0,007 Various Printed wiring board, through-hole, at plant/GLO U

61

P

PartsQuantity

one module (2500W)

Quantity SPVS

(4200W)Unit Quantity per F.U.


Casing 1,400 2,352 kg 0,044 Extrusion Section bar extrusion, aluminium/RER U

Cables 5,510 9,257 kg 0,172 Wire drawing Wire drawing, copper/RER U

Screws and clamps

9,800 16,464 kg 0,306 Sheet rolling Sheet rolling, steel/RER U

All parts 0,021 0,356 MWh 0,0066 Electricity Electricity, medium voltage, production UCTE, at grid/UCTE U

DT


Lorry 34,855*2=69,710 kg

60 km 4183 38,821 Transport, lorry >16t, fleet avera-ge/RER U

Train 200 km 13942 129,392 Transport, freight, rail/RER U

Ship 18000 km 1254780 11645,290 Transport, transoceanic freight ship/OCE U

U

ActivityQuantity

one module (2500W)

Quantity SPVS

(4200W)Unit Quantity per F.U. (kWh) In SimaPro

Energy loss/year [1]

0,082 0,138 MWh 0,0026 Electricity, PV, at 3kWp slanted-roof, multi-Si, panel, mounted/CH U



[1] 3% of energy is lost: 0,138 MWh per year

62

4.4.4 Support Structure InventoryModel: Fischer Solar-Fix (28,16m2)On Ecoinvent: flat roof construction, on roof/m2/CH/I (1m2)

PP

Parts

Quantity one

module (1m2)

Quantity SPVS

(28,16m2)Unit

N. module per F.U.

Lifespan (years)

N. parts /lifespan


Bars 2,519 70,941 kg 1 25 1 70,941/107,75=0,658

Aluminium Aluminium, production mix, wrought alloy, at plant/RER U

Sheets 0,267 7,513 kg 1 25 1 0,070 Steel Steel, low-alloyed, at plant/RER U


Various 1,922 54,126 kg 1 25 1 0,500 HDPE Polyethylene, HDPE, granulate, at plant/RER U

Insulating 0,008 0,234 kg 1 25 1 0,002 PS Polystyrene, high impact, HIPS, at plant/RER U

P

Parts

Quantity one

module (1m2)

Quantity SPVS



Bars 1,223 34,440 kg 0,320 Extrusion Section bar extrusion, alumi-nium/RER U

Sheets 0,267 7,513 kg 0,070 Lamination Sheet rolling, steel/RER U

DT


Lorry 133,330 kg 50 km 6666 61,860 Transport, lorry >16t, fleet average/RER U

Train 300 km 39999 371,220 Transport, freight, rail/RER U

Van 100 km 13333 123,740 Transport, van <3.5t/RER U

UActivity

Quantity one

module (1m2)

Quantity SPVS


No consumption



4.4.5 Electric Installation InventoryModel: NMG-Schneider (28,16m2)On Ecoinvent: Electric installation, photovoltaic plant, at plant/CH/I (22,8m2)

PP

Parts

Quantity one

module (22,8m2)

Quantity SPVS

(28,16m2)Unit

N. module per F.U.

Lifespan (years)

N. parts /lifespan


Cables and metallic parts

14,700 18,228 kg 1 25 1 18,228/107,75=0,169

Copper Copper, at regional storage/RER U

0,020 0,025 kg 1 25 1 0,0002 Brass Brass, at plant/CH U

0,040 0,050 kg 1 25 1 0,0005 Zinc Zinc, primary, at regional storage/RER U

0,860 1,066 kg 1 25 1 0,010 Steel Steel, low-alloyed, at plant/RER U

Covering 0,230 0,285 kg 1 25 1 0,003 Nylon Nylon 6, at plant/RER U

17,610 21,836 kg 1 25 1 0,203 PE Polyethylene, HDPE, granulate, at plant/RER U

2,130 2,641 kg 1 25 1 0,025 PVC Polyvinylchloride, bulk polymerised, at plant/RER U

0,200 0,248 kg 1 25 1 0,002 PC Polycarbonate, at plant/RER U

PParts

Quantity one

module (22,8m2)

Quantity SPVS



Cables 14,700 18,228 kg 0,169 Wire drawing Wire drawing, copper/RER U

DT


Lorry 44,378 kg 50 km 2219 20,59 Transport, lorry 20-28t, fleet average/CH U

Train 300 km 13313 123,6 Transport, freight, rail/CH U

UActivity

Quantity one

module (1m2)

Quantity SPVS


No consumption



63

64

Photovoltaic Module LCIA

Inverter LCIA

4.5 Phase III: Life Cycle Impact Assessment (LCIA)

PP P DT DM

PP P DT DMU

U

65

Support Structure LCIA

Electric Installation LCIA

PP P DT DM

PP P DT DM

66

The results show us a very interesting fact: during the life cycle of a PV system, the most of environmental impact is concentrated on pre-production + production phases. It is very interesting to note that disposal phase has a minimum impact. Nowadays, in fact, almost the entire PV system can be recycled.

The single component with the highest impact is, obviously, the PV module: this is because it has cells made of silicon, that is difficult to produce and it has an high environmental impact. Furthermore there are many materials used in production, in particular aluminium and solar glass have both an high impact.

The second most impacting component is the inverter, in fact it has many electric components like capacitors, integrated circuits and printed wiring board. But it is the cooper the material most used in pre-production. Interesting is to see that in production the use of electricity is higher compared to the other processes: this is due to the fact that processing metals requires high amount of energy.

In the support structure and the electric installation we have a large quantity of metals that they represent the highest environmental impact of the components, in particular aluminium and copper.

4.6 Phase IV: Interpretation

67

LIFE CYCLE PHASE mPOINTSPreProduction (PP) + Production (P) 4337 mPtUse (U) 162 mPtDistribution (DT) 83 mPtDisposal (DM) 37 mPt

COMPONENT mPOINTSPhotovoltaic Module 2772 mPtInverter 1038 mPtSupport Structure 547 mPtElectric Installation 318 mPt

Component Life Cycle

Life Cycle Phase

70

The results of LCA have been elaborated through the IPSA (Strategic Design Priorities Identification) method, obtaining a priority list in relation to the seven most important LCD strategies.

1. Minimise Materials Consumption;2. Minimising Energy Consumption;3. Minimising Toxic Emissions;4. Renewable and Bio-Compatible Resources;5. Optimisation of Product Lifespan;6. Improve Lifespan of Materials;7. Design for Disassembly.

The priorities for the strategies of environmental impact reduction are a set of formulas that use the results from a Life Cycle Assessment Software, in this case SimaPro, also named Eco-indicator points. Upon those formula coefficients need to be applied according to different reasoning. For each strategy there is one formula. An exception to this are the Renewable and Bio-Compatible Resources and the Design for Disassembly, because the latter does not have an appointed priority. As for Renewable and Bio-Compatible Resources the sum of Eco-indicator points gives the priority rank, without a formula.

From IPSA of the whole PV system there are some interesting conclusions to do. As we might expect, the higer priority is Minimise Material Consumption: in fact isn’t so difficult reduce and optimise the materials used. Optimisation of Product Lifespan has medium priority: today every PV system is used under its possibility about time. There are many possibilities to improve this aspect. Another medium priority is Minimising Toxicity Emission

5.1 PV System Life Cycle Guidelines and Priorities

71

that is caused by the fact that there are a lot of electronic pieces in the system. Improve Lifespan of Materials has a low priority since, usually, it tends to use them in a correct way. Another low priority is Minimising Energy Consumption, because, in standard conditions, there’s no energy used but only energy lost. The last priority is Renewable and Bio-Compatible Resources, because the conservation of resources it’s already taken into account.

Photovoltaic System Energy SchemeStrategy IPSA Formula IPSA IPSA n. PriorityMinimise MaterialsConsumption

c x EI[PP +P + DT + DM]

PHOTOVOLTAIC SYSTEM 2,628 1,00 P: HIGHMinimising Energy Consumption

c x EI[consumed energy + impact reduction due to losses reduction]

PHOTOVOLTAIC SYSTEM 0,146 0,06 P: LOWMinimising Toxic Emissions EI.t[(PP + P + DT + U + DM) toxic materials/processes]PHOTOVOLTAIC SYSTEM 1,09 0,41 P: MEDIUMRenewable and Bio-Compatible Resources

EI.c[consumed energy + consumed materials]

PHOTOVOLTAIC SYSTEM 0,041 0,02 P: LOWOptimisation of Product Lifespan

∑fDpc.i x EIc.i[PP + P + DT + DM]

PHOTOVOLTAIC SYSTEM 1,354 0,52 P: MEDIUMImprove Lifespan of Materials

c x EI[PP landfilled materials] + EI[DM landfilled materials]

PHOTOVOLTAIC SYSTEM 0,595 0,23 P: LOWIPSA max 2,628

72

Photovoltaic System Strategic Design Priorities

The design guidelines for integrating environmental requirements in the development phase of the examined product are grouped into the following strategies:

Minimise Materials Consumption (100% high p.)

Optimisation of Product Lifespan (52% medium p.)

Minimising Toxic Emissions (41% medium p.)

Improve Lifespan of Materials (23% low p.)

Minimising Energy Consumption (6% low p.)

Renewable and Bio-Compatible Resources (2% low p.)

73

Strategic Design Priorities - Components

The 100% value coresponds to the highest IPSA value - in this case the “Minimise Material Consumption” of the Photovoltaic Module (1,34 Pt).

Minimise Materials Consumption (100% high, 51%, 29%, 17% medium)

Optimisation of Product Lifespan (60% high, 22%, 12% medium, 7% low)

Minimising Toxic Emissions (32%, 29%, 18% medium, 3% low)

Improve Lifespan of Materials (28% medium, 8%, 5%, 3% low)

Minimising Energy Consumption (7%, 4%, 0%, 0% low)

Renewable and Bio-Compatible Resources (3%, 0%, 0%, 0% low)

PV ModuleInverterSupport StructureElectric Installation

74

Photovoltaic Module Energy Scheme

Strategy IPSA Formula IPSA IPSA n. PriorityMinimise MaterialsConsumption


PHOTOVOLTAIC MODULE 0,5*(2,513+0,081+0,056+0,026) 1,34 1,00 P: HIGHMinimising Energy Consumption


PHOTOVOLTAIC MODULE 0,9*0,098 0,088 0,07 P: LOWMinimising Toxic Emissions EI.t[(PP + P + DT + U + DM) toxic materials/processes]PHOTOVOLTAIC MODULE 0,426 0,32 P: LOWRenewable and Bio-Compatible Resources


PHOTOVOLTAIC MODULE 0,038 0,03 P: LOWOptimisation of Product Lifespan


PHOTOVOLTAIC MODULE 0,3*(2,513+0,081+0,056+0,026) 0,803 0,60 P: MEDIUMImprove Lifespan of Materials


PHOTOVOLTAIC MODULE 0,7*0,503+0,026 0,378 0,28 P: LOWIPSA max 1,34

75

Inverter Energy Scheme



INVERTER 0,7*(0,719+0,24+0,011+0,004) 0,682 1,00 P: HIGHMinimising Energy Consumption


INVERTER 0,9* 0,064 0,058 0,09 P: LOWMinimising Toxic Emissions EI.t[(PP + P + DT + U + DM) toxic materials/processes]INVERTER 0,39 0,57 P: MEDIUMRenewable and Bio-Compatible Resources


INVERTER 0,0015 0,00 P: LOWOptimisation of Product Lifespan


INVERTER 0,3*(0,719+0,24+0,011+0,004) 0,292 0,43 P: MEDIUMImprove Lifespan of Materials


INVERTER 0,7*0,144+0,0008 0,102 0,15 P: LOWIPSA max 0,682

76

Support Structure Energy Scheme



SUPPORT STRUCTURE 0,7*(0,504+0,022+0,0157+0,005) 0,383 1,00 P: HIGHMinimising Energy Consumption


SUPPORT STRUCTURE 0,00 0,00 P: LOWMinimising Toxic Emissions EI.t[(PP + P + DT + U + DM) toxic materials/processes]SUPPORT STRUCTURE 0,037 0,10 P: LOWRenewable and Bio-Compatible Resources


SUPPORT STRUCTURE 0,0012 0,00 P: LOWOptimisation of Product Lifespan


SUPPORT STRUCTURE 0,3*(0,504+0,022+0,0157+0,005) 0,164 0,43 P: MEDIUMImprove Lifespan of Materials


SUPPORT STRUCTURE 0,7*0,101+0,001 0,072 0,19 P: LOWIPSA max 0,383

77

Electric Installation Energy Scheme



ELECTRIC INSTALLATION 0,7*(0,3+0,015+0,0004+0,003) 0,223 0,94 P: HIGHMinimising Energy Consumption


ELECTRIC INSTALLATION 0,00 0,00 P: LOWMinimising Toxic Emissions EI.t[(PP + P + DT + U + DM) toxic materials/processes]ELECTRIC INSTALLATION 0,237 1,00 P: HIGHRenewable and Bio-Compatible Resources


ELECTRIC INSTALLATION 0,000057 0,00 P: LOWOptimisation of Product Lifespan


ELECTRIC INSTALLATION 0,3*(0,3+0,015+0,0004+0,003) 0,095 0,40 P: MEDIUMImprove Lifespan of Materials


ELECTRIC INSTALLATION 0,7*0,06+0,0006 0,043 0,18 P: LOWIPSA max 0,237

78

How much can it be gained in terms of environmental impact reduction if the design of the product is in such a way that uses infinitely less material in respect to the existing one?

Formulac x EI [PP + P + DT + DM]c (maximum reduction coefficient) = 0,9 > 0,5c = 0,7: in uncertainty casesEI (Eco-Indicator) = indicator of aggregated environmental impact

Reducing resources indcates a design aimed at reducing the usage of materials for the entire product life cycle. Using less materials drops the environmental impact of a product due to minimising the resources being extracted, but also due to the reduction or diminishing of the fabrication processes and the produced waste. Apart from their environmental costs products obviously also have economical costs. Less materials means savings in both contexts.

Following the results of this calculation, Minimise Materials Consumption has the highest priority with a combined sum of 2,683 points (1,34 Photovoltaic Module; 0,682 Inverter; 0,383 Support Structure; 0,223 Electric Installation). A sum of the individual components was made because applying a coefficient for all the system results would have proven inaccurate.

It is important to say that the coefficient to calculate the priorities it’s not the same for every component. We can see that it is 0,5 for PV module and 0,7 for the other components: this it means the material content could decrease of 50% for the PV module and up to 70% for the other components.

5.2 Minimise Materials Consumption (Σ 2,628 Pt)

79

Minimise Materials Consumption is high only for the PV module, because it is the main part of the PV system. The priority on the inverter is medium, for support structure and electric installation is low.

Strategy IPSA Formula IPSA IPSA n. PriorityMinimise Materials Consumption c x EI[PP +P + DT + DM]

PHOTOVOLTAIC MODULE 0,5*(2,513+0,081+0,056+0,026) 1,34 1,00 P: HIGHMinimise Materials Consumption c x EI[PP +P + DT + DM]INVERTER 0,7*(0,719+0,240+0,011+0,004) 0,682 0,51 P: MEDIUMMinimise Materials Consumption c x EI[PP +P + DT + DM]SUPPORT STRUCTURE 0,7*(0,504+0,022+0,0157+0,005) 0,383 0,29 P: LOWMinimise Materials Consumption c x EI[PP +P + DT + DM]ELECTRIC INSTALLATION 0,7*(0,3+0,015+0,0004+0,003) 0,223 0,17 P: LOWIPSA max 1,34

80

Pre-Production + Production mPOINTSPV Cell 1900 mPtAluminium 233 mPtSolar Glass 180 mPtCopper 47,2 mPtEVA 39,9 mPtElectricity 39,1 mPtPVC 37,5 mPtTempering 34,6 mPtCardboard 33,4 mPtGlass Fiber 22,7 mPtPE 14,7 mPtSilicone 4,9 mPtNatural Gas 4,7 mPtWire Drawing 2,6 mPt

Photovoltaic Module

81

5.2.1 Minimise Materials ConsumptionPV Module Design Guidelines

Minimise material content:• Dematerialise the product or some of its components• Design the lower structure to eliminate the frame • Design only one frame from module to module• Design an array frame to eliminate the single module

frame• Design to integrate the frame with the support structure• Increase the cell size to reduce connection between

each other, without compromising the efficiency of the system

• Prefer square cells (not smoothed) to optimise the use of material

• Avoid over-sized dimensions • Apply ribbed to the base and to the hard-sheet to

increase structural stiffness and to reduce weight• Avoid extra components with little functionality

Minimise scraps and discards:• Select processes that reduce scraps and discarded

materials during production• Engage simulation systems to optimise transformation

processes

Minimise or avoid packaging:• Avoid packaging • Choose efficient transport systems as inflatable or

angular packaging• Use only one packaging for more modules• Apply materials only where absolutely necessary

82

Engage more consumption-efficient systems:• Design for more efficient consumption of operational

materials• Design to be self-cleaning• Design the frame to drain water• Design a system as windscreen wiper to clean the

module surface • Design self-cleaning systems linked to sensors of dirt• Design for more efficient supply of raw materials • Design for more efficient use of maintenance materials • Design systems for consumption of passive materials

(water, wind)• Design for cascading recycling systems • Facilitate the person managing maintanance to reduce

materials consumption• Design an anchoring system to facilitate maintenance• Design module with an integrated cleaning system

Engage systems of flexible materials consumption:• Engage digital support systems with dynamic

configuration • Design a monitoring system to identify precise dirt areas • Design dynamic materials consumption for different

operational stages• Engage sensors to adjust materials consumption

according to differentiated operational stages• Reduce resource consumption in the product’s default

state

83

Pre-Production + Production mPOINTSCopper 280 mPtElectricity 215 mPtCapacitor, Tantalum 119 mPtIntegrated Circuit 118 mPtPrinted Wiring Board 54,2 mPtCapacitor, Film 45,6 mPtInductor 30,9 mPtDiode 21,6 mPtWire Drawing 15,1 mPtTransistor 13,7 mPtCardboard 9,3 mPtAluminium 8,7 mPtCapacitor, Electrolyte 8,2 mPtConnector 7,9 mPtSheet Rolling 7 mPtSection Bar Extrusion 2,8 mPtPS 1,9 mPt

Inverter

84

5.2.2 Minimise Materials ConsumptionInverter Design Guidelines

Minimise material content:• Design inner components to optimise space and use

less material• Digitalise the product or some of its components,

sending the data directly to mobile phone in order to replace the front display

• Minimise case material content to enhance fitting and to reduce empty spaces

• Apply ribbed to the case to increase structural stiffness• Avoid extra components with little functionality


materials during production of the case and the integrated circuits

• Engage simulation systems to optimise transformation processes

Minimise or avoid packaging:• Design case to be stackable and optimised for transport• Apply materials only where absolutely necessary• Design the inverter to be mounted in the location of final

use• Design the package to be part (or to become a part) of

the product

Engage more consumption-efficient systems:• Design for more efficient use of maintenance materials • Design the case with an anti-dust material• Optimise shapes, grids and holes

85

• Facilitate the person managing maintanance to reduce materials consumption

• Design the case to be easily removable to remove inner dust

86

Pre-Production + Production mPOINTSAluminium 446 mPtPE 48,9 mPtExtrusion 39,9 mPtSheet Rolling 37,5 mPtSteel 9,1 mPt

Support Structure

87

5.2.3 Minimise Materials ConsumptionSupport Structure Design Guidelines

Minimise material content:• Dematerialise the product or some of its components• Design the support structure integrated with the module

frame and with the the roof• Avoid over-sized dimensions • Apply ribbed to the structure to increase structural

stiffness• Avoid extra components with little functionality


materials during production • Engage simulation systems to optimise transformation

processes

Minimise or avoid packaging:• Avoid packaging • Choose efficient transport systems with minimal (or not

present) packaging • Optimise packaging for more support structures• Apply materials only where absolutely necessary


materials• Design the structure with a shape to avoid store of dirt

or water• Design for more efficient supply of raw materials • Design for more efficient use of maintenance materials

88

• Design systems for consumption of passive materials (water, wind)

• Design for cascading recycling systems • Facilitate the person managing maintanance to reduce

materials consumption• Design an anchoring system to facilitate maintenance• Set the product’s default state at minimal materials

consumption

Engage systems of flexible materials consumption:• Engage digital support systems with dynamic

configuration • Design a monitoring system to identify precise dirt areas• Design dynamic materials consumption for different

operational stages• Engage sensors to adjust materials consumption

according to differentiated operational stages• Reduce resource consumption in the product’s default

state

89

Pre-Production + Production mPOINTSCopper 275 mPtPE 19,8 mPtWire Drawing 14,9 mPtPVC 2,5 mPtNylon 1,4 mPtSteel 1,3 mPt

Electric Installation

90

5.2.4 Minimise Materials Consumption Electric Installation Design Guidelines

Minimise material content:• Avoid over-sized dimensions • Avoid extra components with little functionality


materials during production of the electric cables

Minimise or avoid packaging:• Avoid packaging • Apply materials only where absolutely necessary• Choose efficient transport systems using rubber bands

to hold electric cables toghether• Design the package to be part (or to become a part) of

the product


materials• Design cover to protect electric cables• Design for more efficient supply of raw materials • Design for more efficient use of maintenance materials • Design systems for consumption of passive materials • Design for cascading recycling systems • Facilitate the person managing maintanance to reduce

materials consumption

92

How much can it can be gained in terms of environmental impact reduction if the design of the product is in such a way that is infinitely more durable in comparison to the existing product?

FormulaΣfDpc.i x EIc.i[PP + P + DT + DM]fDp = fattore Durata uso potenzialec = maximum reduction coefficient = 0,9 > 0,5; c = 0,7: in uncertainty casesEI = Eco-Indicator= indicator of aggregated environmental impact

Optimising the lifespan of a products is to design for the extending of the product and its components lifespan and for intensifying product use. A product with longer lifespan than another with the same functionality, generally determines smaller environmental impact. A product with accelerated wear will not only generate untimely waste, but will also determine further impact due to the need of replacing it. Production and distribution of a new product to replace its function involves the consumption of new resources and the further generation of emissions.

Optimisation of product lifespan is an interesting priority for this kind of product: standard PV module, in fact, is usually guaranteed for 25 years and with new technologies, it might be possible increase its life until 40 years. The average lifetime of an Inverter is about an half of the lifetime of a PV module: this component is nowadays guaranteed for 10/12 years but, it could be even longer (20 years) simply replacing malfunctioning or broken sub-components: today we tend often to replace an electronic product, as an inverter, before

5.3 Optimisation of Product Lifespan (Σ 1,354 Pt)

93

the real end of life. It can be possible also extend the lifetime of the support structure and the electric installation until 40 years because they don’t have any particular problems with the lifetime of materials or sub-components. So, the higher priority is for PV module and, after, for the inverter. Both support structure and electric installation have a low priority.

Strategy IPSA Formula IPSA IPSA n. PriorityOptimisation of Product Lifespan


PHOTOVOLTAIC MODULE 0,3*(2,513+0,081+0,056+0,026) 0,803 1,00 P: HIGHOptimisation of Product Lifespan


INVERTER 0,3*(0,719+0,24+0,011+0,004) 0,292 0,36 P: MEDIUMOptimisation of Product Lifespan


SUPPORT STRUCTURE 0,3*(0,504+0,022+0,0157+0,005) 0,164 0,20 P: LOWOptimisation of Product Lifespan


ELECTRIC INSTALLATION 0,3*(0,3+0,015+0,0004+0,003) 0,095 0,12 P: LOWIPSA max 0,803

94

The components that in the PP, P, DT and DM have the highest environmental impact are:

Total EcoIndicator points of current design, 25 years - compared to 37,5 years lifetime extension

Photovoltaic Module

25y37,5y

95

5.3.1 Optimisation of Product Lifespan PV Module Design Guidelines

Reliability design:• Reduce overall number of components• Simplify products• Eliminate weak liaisons

Facilitate upgrading and adaptability:• Enable and facilitate software upgrading• Design reprogrammable monitoring systems for the

surplus energy management• Enable and facilitate hardware upgrading• Design the module in order to replace current cells with

more efficiency cells in the future• Design modular and dynamically configured products to

facilitate their adaptability for changing environments• Design an adaptable module for potential changing of

location • Design onsite upgradeable and adaptable module• Design complementary tools and documentation for the

module upgrading and adaptation

Facilitate maintenance:• Simplify access and disassembly to components to be

maintained: in particular pv cells and potential movement parts

• Avoid narrow slits and holes to facilitate access for cleaning

• Prearrange and facilitate the substitution of short-lived components

• Equip the module with easily usable tools for maintenance as windscreen wiper, water jet or air jet

96

• Equip products with diagnostic and/or auto-diagnostic systems for maintainable components

• Design products for easy on-site maintenance: anchoring system, sensor of dirt

• Design complementary maintenance tools and documentation

• Design products that need less maintenance: less parts, easy shapes, long-lived materials

Facilitate repairs:• Arrange and facilitate disassembly and re-attachment of

easily damageable components as pv cells• Design components according to standards to facilitate

substitution of damaged parts in order to be always compatible

• Equip products with automatic damage diagnostics system

• Design a sensor that identify the precise broken pv cell with a communication system connected directly to the technical assistance

• Design the module for facilitated onsite repair • Design complementary repair tools, materials and

documentation for cells

Facilitate re-use:• Increase the resistance of easily damaged and

expendable components as pv cells• Arrange and facilitate access and removal of retrievable

components as pv cells• Design modular and replaceable module in order to

replace it in different places• Design components according to standards to facilitate

replacement

97

• Design re-usable auxiliary parts• Design the re-usable packaging: replace cardboard with

inflatable material

Facilitate re-manufacture:• Design and facilitate removal and substitution of pv cells• Design structural parts that can be easily separated

from external/visible ones• Provide easier access to pv cells to be re-manufactured• Calculate accurate tolerance parameters for easily

expendable connections• Design for excessive use of material for easily

deteriorating surfaces• Design the module using a solar glass easy to re-treating

on the surface

98



Inverter

25y37,5y

99

5.3.2 Optimisation of Product Lifespan Inverter Design Guidelines

Reliability design:• Reduce overall number of components, designing a

monocomponent case• Simplify products designing a case with a linear shape

Facilitate upgrading and adaptability:• Enable and facilitate energy management software

upgrading• Design modular and dynamically configured inverter to

facilitate its adaptability for changing environments• Design onsite upgradeable and adaptable inverter• Design complementary tools and documentation for the

inverter adaptation

Facilitate maintenance:• Simplify access and disassembly to the case and the

grid to be maintained• Avoid narrow slits and holes to facilitate access for

cleaning the case, the grid and the wall• Prearrange and facilitate the substitution of short-lived

components as capacitor• Equip the product with easily usable tools for maintenance• Equip products with diagnostic and/or auto-diagnostic

systems for maintainable components • Design a system that alerts the user to possible

malfunctioning: capacitor wear, overuse, over and under voltage, ultrasonic vibrations

• Design products for easy on-site maintenance • Design an easy access to capacitors and integrated

circuits

100

• Design complementary maintenance tools and documentation

• Design products that need less maintenance especially on the capacitors


easily damageable parts as capacitors• Design components according to standards to facilitate

substitution of damaged parts • Equip products with automatic damage diagnostics

system with a sensor that identifies the problem on capacitor or integrated circuit and transmits data to technical assistance

• Design inverter for facilitated onsite repair • Design complementary repair tools, materials and

documentation


expendable internal parts• Arrange and facilitate access and removal of retrievable

components as integrated circuit and printed wiring board

• Design modular and replaceable inverter in order to replace it in different places, working on the rear joints

• Design components according to standards to facilitate replacement

• Design the re-usable packaging: replace cardboard with inflatable material

101

Facilitate re-manufacture:• Design and facilitate removal and substitution of easily

expendable inverter components as capacitors• Design structural parts that can be easily separated

from external/visible ones• Provide easier access to inverter components to be re-

manufactured• Calculate accurate tolerance parameters for easily

expendable connections

102



Support Structure

25y37,5y

103

5.3.3 Optimisation of Product Lifespan Support Structure Design Guidelines


Facilitate upgrading and adaptability:• Enable and facilitate hardware upgrading• Design the support structure in order to replace each

part indipendently• Design modular and dynamically configured products to

facilitate their adaptability for changing environments• Design an adaptable support structure for potential

changing of location • Design onsite upgradeable and adaptable support

structure• Design complementary tools and documentation for the

support structure upgrading and adaptation

Facilitate maintenance:• Simplify access and disassembly to components to be

maintained, in particular possible movement parts• Avoid narrow slits and holes to facilitate access for

cleaning• Prearrange and facilitate the substitution of short-lived

components• Equip the module with easily usable tools for maintenance

as windscreen wiper, water jet or air jet• Equip products with diagnostic and/or auto-diagnostic

systems for maintainable components• Design products for easy on-site maintenance: anchoring

104

system, sensor of dirt• Design complementary maintenance tools and

documentation• Design products that need less maintenance: less parts,

easy shapes, long-lived materials


easily damageable components of the support structure• Design components according to standards to facilitate


system• Design a sensor that identify the precise broken part of

the structure, with a communication system connected directly to the technical assistance

• Design support structure for facilitated onsite repair • Design complementary repair tools, materials and

documentation


expendable components as structure parts more exposed to the bad weather

• Arrange and facilitate access and removal of all parts of the support structure

• Design modular and replaceable module in order to replace it in different places

• Design components according to standards to facilitate replacement

• Design the re-usable packaging: replace cardboard with inflatable material

105

• Design the support structure for secondary use, not only for one kind of pv system


expendable components• Design structural parts that can be easily separated

from external/visible ones• Provide easier access to support structure parts to be

re-manufactured• Calculate accurate tolerance parameters for easily

expendable connections• Design for excessive use of materials in places more

subject to deterioration• Design for excessive use of material for easily

deteriorating surfaces• Design the support structure using an aluminium easy

to re-treating on the surface

106




25y37,5y

107

5.3.4 Optimisation of Product Lifespan Electric Installation Design Guidelines


Facilitate upgrading and adaptability:• Enable and facilitate hardware upgrading• Design the electric installation in order to replace current

cables with more efficiency cables in the future• Design modular and dynamically configured products to

facilitate their adaptability for changing environments• Design an adaptable electric installation for potential

changing of location• Design onsite upgradeable and adaptable electric

installation• Design complementary tools and documentation for the

electric cables adaptation

Facilitate maintenance:• Simplify access and disassembly to electric components

to be maintained• Avoid narrow slits and holes to facilitate access for

cleaning• Prearrange and facilitate the substitution of short-lived

components• Equip the product with easily usable tools for maintenance• Equip products with diagnostic and/or auto-diagnostic

systems for maintainable components

108

• Design a system that alerts the user to possible malfunctioning: cables wear, overuse, over and under voltage, ultrasonic vibrations

• Design products for easy on-site maintenance • Design an easy access to every electric cable• Design complementary maintenance tools and

documentation • Design products that need less maintenance


easily damageable parts • Design components according to standards to facilitate


system with a sensor that identifies the problem on a specific cable and transmits data to technical assistance

• Design electric installation for facilitated onsite repair • Design complementary repair tools, materials and

documentation


expendable cables• Arrange and facilitate access and removal of retrievable

cables• Design modular and replaceable electric installation in

order to replace it in different places• Design components according to standards to facilitate

replacement• Design the re-usable packaging: replace cardboard with

rubber bands

109


expendable cables• Design structural parts that can be easily separated

from external/visible ones• Provide easier access to electric installation components

to be re-manufactured• Calculate accurate tolerance parameters for easily

expendable connections

110

How much can it can be gained in terms of environmental impact reduction, if the design of the product avoids the use of toxic or harmful processes existing already in the product?

Formula usedEI.t [(PP + P + DT + U + DM) materials/toxic processes]EI.t = Eco-Indicator of toxicity [Carcinogens + Resp. organics + Resp. inorganics + Radiations]

Design to facilitate the use of resources that relative to the entire life cycle minimise dangerous emissions and all the processes that characterize it. However it must be remembered that toxic or harmful emissions occur during any stage of the products life cycle and might be caused by certain additives to the material rather than the material itself.

The highest level of toxicity is, obviously, in the PV module. This is due to the fact that every PV cell presents materials as glues or acids used in production process. Another high priority is in the Inverter: many electric parts as capacitors or integrated circuits have some problems with toxicity. The electric installation has a medium priority for the presence of electric cables and the related production. Finally the support structure has lower priority.

5.4 Minimising Toxic Emission (Σ 1,09 Pt)

111

Strategy IPSA Formula IPSA IPSA n. PriorityMinimising Toxic Emissions EI.t[(PP + P + DT + U + DM) toxic materials/processes]

PHOTOVOLTAIC MODULE 0,426 1,00 P: HIGHMinimising Toxic Emissions EI.t[(PP + P + DT + U + DM) toxic materials/processes]INVERTER 0,39 0,92 P: HIGHMinimising Toxic Emissions EI.t[(PP + P + DT + U + DM) toxic materials/processes]SUPPORT STRUCTURE 0,037 0,09 P: LOWMinimising Toxic Emissions EI.t[(PP + P + DT + U + DM) toxic materials/processes]ELECTRIC INSTALLATION 0,237 0,56 P: MEDIUMIPSA max 0,426

112

The toxicity of PV module result the higher respect the same priority in the other components of the PV system. This is beacause the PV cell has got a lot of materials used during the production. The most toxic are: glue for metals, phosphoric acid, acetic acid, hydrochloric acid and nitric acid. It’s obviusly that acids and glues are very dangerous for humans and for our planet and it is important looking for new solutions to avoid a great quantity of theese materials.

Photovoltaic Module

Minimising Toxic Emission

113

5.4.1 Minimising Toxic Emission PV Module Design Guidelines

Select non-toxic and harmless materials:• Avoid toxic or harmful materials for product components• Minimise the hazard of toxic and harmful materials• Avoid materials that emit toxic or harmful substances

during pre-production• Avoid additives that emit toxic or harmful substances• Avoid technologies that process toxic and harmful

materials• Avoid toxic or harmful surface treatments• Design products that do not consume toxic and harmful

materials• Avoid materials that emit toxic or harmful substances

during usage• Avoid materials that emit toxic or harmful substances

during disposal

Select non toxic and harmless energy resources:• Select energy resources that reduce dangerous

emissions during pre-production and production• Select energy resources that reduce dangerous

emissions during distribution• Select energy resources that reduce dangerous

emissions during usage• Select energy resources that reduce dangerous residues

and toxic and harmful waste

114

The inverter is a product with many electronic components inside. In particular, the major toxicity problems are given from the presence of printed wiring boards: they are toxic especially during the production phase, but also during disposal phase. The great quantity of these materials make this priority of medium importance.

Inverter


115

5.4.2 Minimising Toxic Emission Inverter Design Guidelines






during disposal






116

The support structure, obviously, has the lower toxicity priority respect the other components. The main material is the aluminium that it is only a bit tossic for humans especially during the production phase. Anyway this priority is low.

Support Structure


117

5.4.3 Minimising Toxic Emission Support Structure Design Guidelines






during disposal






118

For the electric installation the main problems are similar with the inverter ones. In fact during production and disposal of cables (and other junction parts like capacitors, resistors, diodes), there are toxic emissions as ever electric components. Anyway the priority is medium/low because this components it’s only the minimal part of the entire system.



119

5.4.4 Minimising Toxic Emission Electric Installation Design Guidelines






during disposal






120

How much can it can be gained in terms of environmental impact reduction, if the design of the product achieves for all the material used the following: to recycle, compost or to incinerate in order to regain its energetic content?

Formulac x EI[PP materials to landfill] + EI[DM materials to landfill]c (maximum reduction coefficient) = 0,9 > 0,5c = 0,7: in uncertainty casesEI (Eco-Indicator) = indicator of aggregated environmental impact

A design of adding environmental value to materials (within a product) to avoid premature disposal, by reprocessing them to obtain new prime secondary materials (by recycling or composting) or burning them to recuperate their energetic content.

There is a double advantage in the process:• The environmental impact and the cost of disposal of

the materials are avoided.• The production and acquisition costs connected with

buying virgin materials are avoided.

Naturally the processes of composting, recycling and burning also have their own environmental and economic costs. In conservatory terms we can adopt a series of measures in relation with all the phases of the process of recycling to minimise such costs: collection and transportation; identification and separation; disassembly and/or fragmentation; cleaning and/or washing; pre-production of prime secondary materials.

5.5 Improve Lifespan of Materials (Σ 0,595 Pt)

121

Generally the following principle is followed: the material should be recycled as much as possible before it loses its material properties, then, at that point, the object should be incinerated to recuperate its energy content.

In the SimaPro software an average of most commonly recycled was made because recycling data was not available to this detail. So, the recyled percentage is 90% and the landfill ones is 10%. However this percentage can vary in reality, especially depending on the companies that manage the disposal.

Because it has the highest amount of landfill and of material in general the PV module has the biggest priority among the four, followed by the inverter, the support structure and the electric installation.

Strategy IPSA Formula IPSA IPSA n. PriorityImprove Lifespan of Materials


PHOTOVOLTAIC MODULE 0,7*0,503+0,026 0,378 1,00 P: HIGHImprove Lifespan of Materials


INVERTER 0,7*0,144+0,0008 0,102 0,27 P: LOWImprove Lifespan of Materials


SUPPORT STRUCTURE 0,7*0,101+0,001 0,072 0,19 P: LOWImprove Lifespan of Materials


ELECTRIC INSTALLATION 0,7*0,06+0,0006 0,043 0,11 P: LOWIPSA max 0,378

122

Pre-Production + Production mPOINTSPre-Production (19%) 503 mPtPre-Production (77%) 2010,3 mPtProduction (4%) 81 mPtPre-Production + Production 2594,3 mPtDistribution 56,3 mPtUse 96 mPtDisposal 25,6 mPt

Photovoltaic Module

Potential Impact Avoided

123

5.5.1 Improve Lifespan of Materials PV Module Design Guidelines

Adopt the cascade approach:• Arrange and facilitate recycling of materials in

components with lower mechanical requirements• Facilitate disassembly of copper cables and frame• Facilitate disassembly and transport of pv cells

Select materials with most efficient recycling technologies:• Select materials that easily recover after recycling the

original performance characteristics, paying particular attention to different kinds of recyclable pv cells

• Avoid composite materials or, when necessary, choose easily recyclable ones

• Engage geometrical solutions like ribbing to increase polymer stiffness instead of reinforcing fibres

• Prefer thermoplastic polymers to thermosetting• Design considering the secondary use of the materials

once recycled

Facilitate end-of-life collection and transportation:• Design in compliance with product retrieval system • Minimise cluttering and improve stackability of discarded

products • Design for the compressibility of discarded products • Design modules to be stackables and to optimise space

during transport• Provide the user with information about the disposing

modalities of the product or its parts using a digital codification with recycling mode description

124

Material identification:• Codify different materials to facilitate their identification• Provide additional information about the material’s age,

number of times recycled in the past and additives used • Define time of use of the module to give informations

about recycle• Indicate the existence of toxic or harmful materials,

especially inside pv cell• Use standardised materials identification systems • Arrange codifications in easily visible places• Avoid codifying after component production stages

Minimise the number of different incompatible materials:• Integrate functions to reduce the overall number of

materials and components: integration between frame and support structure

• Monomaterial strategy: only one material per product or per sub-assembly

• Use only one material, but processed in sandwich structures

• Use compatible materials (that could be recycled together) within the product or sub-assembly

• For joining use the same or compatible materials as in components (to be joined)

Facilitate cleaning:• Avoid unnecessary coating procedures• Avoid irremovable coating materials• Facilitate removal of coating materials• Use coating procedures that comply with coated

materials• Avoid adhesives or choose ones that comply with

materials to be recycled

125

• Prefer the dyeing of internal polymers, rather than surface painting

• Avoid using additional materials for marking or codification

• Mark and codify materials during moulding• Codify polymers using lasers

Facilitate combustion:• Select high energy materials for products that are going

to be incinerated• Avoid materials that emit dangerous substances during

incineration• Avoid additives that emit dangerous substances during

incineration• Facilitate the separation of materials that would

compromise the efficiency of combustion (with low energy value)

126

Inverter



127

5.5.2 Improve Lifespan of Materials Inverter Design Guidelines


components with lower mechanical requirements using a polymeric case

• Simplify disassembly of the case • Simplify disassembly of internal components as

capacitors, integrated circuits and printed wiring boards• Arrange and facilitate recycling of materials in

components with lower aesthetical requirements• Arrange and facilitate energy recovery from materials

throughout combustion


original performance characteristics• Avoid composite materials or, when necessary, choose

easily recyclable ones • Engage geometrical solutions like ribbing to increase

polymer stiffness instead of reinforcing fibres• Prefer thermoplastic polymers to thermosetting • Prefer heat-proof thermoplastic polymers to fireproof

additives• Design considering the secondary use of the materials

once recycled

Facilitate end-of-life collection and transportation:• Design in compliance with product retrieval system • Minimise overall weight• Minimise cluttering and improve stackability of discarded

products

128

• Design for the compressibility of discarded products as case

• Design to optimise occupied space of single parts during transport phase

• Provide the user with information about the disposing modalities of the product or its parts using a digital codification with recycling mode description


number of times recycled in the past and additives used • Define time of use of the inverter to give informations

about recycle • Indicate the existence of toxic or harmful materials as

inside the printed wiring board• Use standardised materials identification systems • Arrange codifications in easily visible places• Avoid codifying after component production stages


materials and components: integration between printed wiring boards and isolation parts


• Design case with same material of isolation parts• Use only one material, but processed in sandwich

structures• Use compatible materials (that could be recycled

together) within the product or sub-assembly

129

Facilitate cleaning:• Avoid unnecessary coating procedures as stickers or

labels• Avoid irremovable coating materials• Facilitate removal of coating materials• Use coating procedures that comply with coated


materials to be recycled• Prefer the dyeing of internal polymers, rather than

surface painting• Avoid using additional materials for marking or

codification• Mark and codify materials during moulding• Codify polymers using lasers

130

Support Structure

Pre-Production + Production mPOINTSPre-Production (19%) 101 mPtPre-Production (77%) 403 mPtProduction (4%) 22 mPtPre-Production + Production 526 mPtDistribution 15,7 mPtUse 0 mPtDisposal 4,9 mPt


131

5.5.3 Improve Lifespan of Materials Support Structure Design Guidelines


components with lower mechanical requirements• Facilitate disassembly of the aluminium from the other

materials• Arrange and facilitate energy recovery from materials

throughout combustion


original performance characteristics • Recover more aluminium that which is possible• Avoid composite materials or, when necessary, choose

easily recyclable ones• Engage geometrical solutions like ribbing to increase

polymer stiffness instead of reinforcing fibres• Prefer thermoplastic polymers to thermosetting• Design considering the secondary use of the materials

once recycled


products• Design for the compressibility of discarded products as

aluminium planks, clamps, hooks• Provide the user with information about the disposing


132

Material identification:• Codify different materials to facilitate their identification:

in particular separate metals from polymers• Provide additional information about the material’s age,

number of times recycled in the past and additives used • Define time of use of the module to give informations

about recycle• Use standardised materials identification systems • Arrange codifications in easily visible places• Avoid codifying after component production stages


materials and components: integration between frame and support structure


• Use compatible materials (that could be recycled together) within the product or sub-assembly

• For joining use the same or compatible materials as in components (to be joined): utilize steel also where polymer is usually used

• Design removable junctions

Facilitate cleaning:• Avoid unnecessary coating procedures as stickers or

labels• Avoid irremovable coating materials• Facilitate removal of coating materials• Use coating procedures that comply with coated


materials to be recycled

133

• Prefer the dyeing of internal polymers, rather than surface painting

• Avoid using additional materials for marking or codification

• Mark and codify materials during moulding• Codify polymers using lasers

Facilitate combustion:• Select high energy materials for products that are going

to be incinerated• Avoid materials that emit dangerous substances during

incineration• Avoid additives that emit dangerous substances during

incineration• Facilitate the separation of materials that would

compromise the efficiency of combustion (with low energy value)

134




135

5.5.4 Improve Lifespan of Materials Electric Installation Design Guidelines


components with lower mechanical requirements• Simplify disassembly of cables


original performance characteristics• Avoid composite materials or, when necessary, choose

easily recyclable ones • Engage geometrical solutions like ribbing to increase

polymer stiffness instead of reinforcing fibres• Prefer thermoplastic polymers to thermosetting • Design considering the secondary use of the materials

once recycled


products• Design for the compressibility of discarded products• Design to optimise occupied space of single parts during

transport phase• Provide the user with information about the disposing


136


number of times recycled in the past and additives used • Define time of use of the inverter to give informations

about recycle • Indicate the existence of toxic or harmful materials• Use standardised materials identification systems • Arrange codifications in easily visible places• Avoid codifying after component production stages


materials and components• Use compatible materials (that could be recycled

together) within the product or sub-assembly

Facilitate cleaning:• Avoid unnecessary coating procedures• Avoid irremovable coating materials• Facilitate removal of coating materials• Use coating procedures that comply with coated


materials to be recycled• Prefer the dyeing of internal polymers, rather than

surface painting• Avoid using additional materials for marking or

codification• Mark and codify materials during moulding• Codify polymers using lasers

137

Strategy IPSA Formula IPSA IPSA n. PriorityMinimising Energy Consumption c x EI[consumed energy + impact reduction due to losses reduction]

PHOTOVOLTAIC MODULE 0,9*0,098 0,088 1,00 P: HIGHMinimising Energy Consumption c x EI[consumed energy + impact reduction due to losses reduction]

INVERTER 0,9* 0,064 0,058 0,66 P: MEDIUMMinimising Energy Consumption c x EI[consumed energy + impact reduction due to losses reduction]

SUPPORT STRUCTURE 0 0,00 P: LOWMinimising Energy Consumption c x EI[consumed energy + impact reduction due to losses reduction]

ELECTRIC INSTALLATION 0 0,00 P: LOWIPSA max 0,069

How much can it can be gained in terms of environmental impact reduction, if the design of the product uses infinitely less energy during use phase, compared to the existing product?

Formulac x EI [consumed energy + impact reduction due to losses reduction]c (maximum reduction coefficient) = 0,9 > 0,5c = 0,7: in uncertainty casesEI (Eco-Indicator) = indicator of aggregated environmental impact

Each PV system, designed and installed in the right way, should have no energy consumed during use. Theoretically, no components, in standard condition, should requires a use of external energy. However the PV system has got some losses. Especially in the PV module and the inverter the produced energy waste is about 10% and 3% respectively: for this reason the PV module priority is the highest, followed by the inverter ones.

5.6 Minimising Energy Consumption (Σ 0,146 Pt)

138

5.6.1 Minimising Energy Consumption PV Module Design Guidelines

Minimise energy consumption during pre-production and production:• Select materials with low energy intensity• Utilize recycled aluminium• Looking for materials and processes with lower energy

consumption than silicon during production phase• Select processing technologies with the lowest energy

consumption possible

Minimise energy consumption during transportation and storage:• Design compact photovoltaic module with high storage

density• Scale down the product weight• Scale down the packaging weight• Decentralise activities to reduce transportation volumes• Select local material and energy sources

Select systems with energy-efficient operation stage:• Design attractive products for collective use• Design sharing networks, energy surplus, decentralized

systems for collective use• Design new communication strategies• Design to reduce loss of the system due to wear and

environmental causes• Design for energy-efficient maintenance• Design manual systems for cleaning and mainenance,

manageable from final user• Engage highly efficient energy conversion systems

139

• Looking for the most advanced technologies with more efficient systems

• Design/engage highly efficient power transmission• Design for maximum operating temperature• Design taking into account the balance of system (BOS)• Use highly caulked materials and technical components• Design the module using shapes and material that allow

dispersion of the heat to maintain system efficiency• Design energy recovery systems, also to replace

batteries• Design energy-saving systems• Design to avoid the stand-by, in case of an automation

system for movement

Engage dynamic consumption of energy:• Engage digital dynamic support systems to control

energy expenditure and manage in-grid exchange• Design dynamic energy consumption systems for

differentiated operational stages• Engage sensors to adjust consumption during

differentiated operational stages• Design a monitoring system to identify possible

inefficiency• Equip machinery with intelligent power-off utilities• Design the possibility to switch off the system

140

5.6.2 Minimising Energy Consumption Inverter Design Guidelines

Minimise energy consumption during pre-production and production:• Select materials with low energy intensity• Minimise the use of copper, aluminum and the others

electronic components with a large energy waste

Minimise energy consumption during transportation and storage:• Minimise energy consumption during transportation and

storage• Design compact inverter with high storage density• Scale down the product weight• Scale down the packaging weight


systems for collective use (an inverter for more users)• Engage highly efficient energy conversion systems• Looking for the most advanced technologies with more

efficient systems• Design/engage highly efficient power transmission• Design for maximum operating temperature• Use highly caulked materials and technical components• Design the inverter taking into account materials and

shapes that allow dispersion of the heat in order to maintain the efficiency

• Design energy-saving systems• Design an on/off system activated manually or

automatically only during the real use of energy

141



differentiated operational stages (in relation with different power demands)

• Engage sensors to adjust consumption during differentiated operational stages

• Equip machinery with intelligent power-off utilities• Design the possibility to switch off the inverter (instead

of stand-by)

142

5.6.3 Minimising Energy Consumption Support Structure Design Guidelines

Minimise energy consumption during pre-production and production:• Select materials with low energy intensity• Utilize recycled aluminium• Select processing technologies with the lowest energy

consumption possible

Minimise energy consumption during transportation and storage:• Design compact support structure with high storage

density• Scale down the product weight• Scale down the packaging weight• Decentralise activities to reduce transportation volumes• Select local material and energy sources


systems for collective use• Design to reduce loss of the support structure due to

wear and environmental causes• Design for energy-efficient maintenance• Design manual systems for cleaning and mainenance,

manageable from final user• Use highly caulked materials and technical components• Design the module using shapes and material that allow

dispersion of the heat to maintain system efficiency• Design energy recovery systems, also to replace

batteries

143

• Design energy-saving systems• Design to avoid the stand-by, in case of an automation

system for movement

144

5.6.4 Minimising Energy Consumption Electric Installation Design Guidelines

Minimise energy consumption during pre-production and production:• Select materials with low energy intensity• Minimise the use of copper and the others electronic

components with a large energy waste• Engage efficient machinery

Minimise energy consumption during transportation and storage:• Minimise energy consumption during transportation and

storage• Design compact cables with high storage density• Scale down the product weight• Scale down the packaging weight


systems for collective use• Design for energy-efficient operational stages• Design for energy-efficient maintenance• Design manual systems for cleaning and mainenance,

manageable from final user• Engage highly efficient energy conversion systems• Looking for the most advanced technologies with more

efficient systems• Design/engage highly efficient power transmission• Design for maximum operating temperature• Use highly caulked materials and technical components• Design energy-saving systems

145



differentiated operational stages (in relation with different power demands)

• Engage sensors to adjust consumption during differentiated operational stages

• Equip machinery with intelligent power-off utilities

146

How much can it can be gained in terms of environmental impact reduction, if the design of the product uses exclusively renewable materials and energy, also for those not present in the product at the beginning?

FormulaEI.c [consumed energy + consumed materials]EI .c = Eco-Indicator conservation [Resources = Minerals + Fossil fuels]

For this formula the Eco-indicator points from the life cycle assessment software (SimaPro) that are generated are introduced directly in the calculation sheet.

Design with the target to save resources for future generations, preferring renewable resources, or at least non-exhaustible ones. It refers both to selection of renewable and bio-compatible materials and energy resources.

Many of the inventoried materials are renewable and, for this, we can notice a low priority in this strategy. However, there are some materials that require, during pre-production and disposal phases, a huge amount of energy, that is usually generated in the traditional way using fossil fuel. Most common are aluminium and copper but also special components as photovoltaic cells, solar glass, capacitor with tantalum, integrated circuit and printed wiring board.Apart from this appreciations the results tend to be good in every macro-component of PV system.

5.7 Renewable & Bio-Compatible Resources (Σ 0,04 Pt)

147

Strategy IPSA Formula IPSA IPSA n. PriorityRenewable and Bio-Compatible Resources


PHOTOVOLTAIC MODULE 0,038 1,00 P: HIGHRenewable and Bio-Compatible Resources


INVERTER 0,0015 0,04 P: LOWRenewable and Bio-Compatible Resources


SUPPORT STRUCTURE 0,0012 0,03 P: LOWRenewable and Bio-Compatible Resources


ELECTRIC INSTALLATION 0,000057 0,00 P: LOWIPSA max

148

In the PV module the less renewable component is the PV cell because the process for the recycle is not so easy, especially during the division of the silicon from the others materials: but, nowadays, technologies to do this kind of recycle, are improving day after day.

Photovoltaic Module

149

5.7.1 Renewable and Bio-Compatible Resources PV Module Design Guidelines

Select renewable and bio-compatible materials:• Use renewable materials• Avoid exhaustive materials• Use residual materials of production processes• Use retrieved components from disposed products• Use recycled materials, alone or combined with primary

materials• Use bio-degradable materials

Select renewable and bio-compatible energy resources:• Use renewable energy resources• Engage the cascade approach• Select energy resources with high second-order

efficiency

150

The less renewable components of the inverter are capacitors, integrated circuit and printed wiring board. In fact, they are classified as electronic waste but, today, the recycle of theese parts is not so difficult. This is why the priority is low.

Inverter

151

5.7.2 Renewable and Bio-Compatible Resources Inverter Design Guidelines




efficiency

152

This priority for the support structure is really low: in fact the main component is the aluminium and, today, is not difficult to produce and recyle it, even though it’s always important to search new solutions to use more renewable and bio-compatible resources.

Support Structure

153

5.7.3 Renewable and Bio-Compatible Resources Support Structure Design Guidelines




efficiency

154

In the electric installation are included many electric parts but, the main components, are electric cables, made of copper. This priority is too low, because they’re almost totally recyclable and recycled yet: in fact the IPSA value is near zero.


155

5.7.4 Renewable and Bio-Compatible Resources Electric Installation Design Guidelines




efficiency

156

Design for Disassembly does not have a precise priority or a formula. However some of the guidelines can be found as part of Optimisation of Product Lifespan and Improve Lifespan of Materials priority calculations.

Design for Disassembly is an individual guideline not only because it’s practical for many of the strategies of environmental impact but also because here the designer can play a substantial role.

In fact, is a strategy aimed at creating easily disassembled components, this will simplify products maintenance, repair, updating and re-manufacturing. Facilitate materials separation is positive for their recycle (if they were incompatible) and for their special treatment (if they were toxic or harmful).

Every PV system, thanks to its modularity, is easily disassembled. It is important to start the disassembly from the PV module and the support structure. Only after that, the inverter and the electronic installation. All components are a “mine” of materials (also precious metals): is fundamental to recycle or reuse them. Also during the life cycle, it’s not difficult to replace a single part without compromising the entrie PV system.

5.8 Design for Disassembly

157

5.8.1 Design for Disassembly PV System Design Guidelines

Reduce and facilitate operations of disassembly and separation:

Overall architecture:• Prioritise the disassembly of toxic and dangerous

components or materials• Prioritise the disassembly of components or materials

with higher economic value• Prioritise the disassembly of more easily damageable

components• Engage modular structures• Divide the product into easily separable and

manipulatable sub-assemblies• Minimise overall dimensions of the product• Minimise hierarchically dependent connections between

components• Minimise different directions in the disassembly route of

components and materials• Increase the linearity of the disassembly route• Engage a sandwich system of disassembly with central

joining elements

Shape of components and parts:• Avoid difficult-to-handle components• Avoid asymmetrical components, unless required• Design leaning surfaces and grabbing features in

compliance with standards• Arrange leaning surfaces around the product’s centre of

gravity• Design for easy centring on the component base

158

Shape and accessibility of joints:• Avoid joining systems that require simultaneous

interventions for opening• Minimise the overall number of fasteners• Minimise the overall number of different fastener types

(that demand different tools)• Avoid difficult-to-handle fasteners• Design accessible and recognisable entrances for

dismantling• Design accessible and controllable dismantling points

Engage reversible joining systems:• Employ two-way snap-fit• Employ joints that are opened with common tools• Employ joints that are opened with special tools, when

opening could be dangerous• Design joints made of materials that become reversible

only in determined conditions• Use screws with hexagonal heads• Prefer removable nuts and clips to self-tapping screws• Use screws made of materials compatible with joint

components, to avoid their separation before recycling• Use self-tapping screws for polymers to avoid using

metallic inserts

Engage easily collapsible permanent joining systems:• Avoid rivets on incompatible materials• Avoid staples on incompatible materials• Avoid additional materials while welding• Weld with compatible materials• Prefer ultrasonic and vibration welding with polymers• Avoid gluing with adhesives• Employ easily removable adhesives

159

Co-design special technologies and features for crushing separation:• Design thin areas to enable the taking off of incompatible

inserts, by pressurised demolition• Co-design cutting or breaking paths with appropriate

separation technologies for incompatible materials separation

• Equip the product with a device to separate incompatible materials

• Employ joining elements that allow their chemical or physical destruction

• Make the breaking points easily accessible and recognisable

• Provide the products with information for the user about the characteristics of crushing separation

Use materials that are easily separable after being crushed.Use additional parts that are easily separable after crushing of materials.

162

YES PARTLY NO NOT APPLICABLE

Did you dematerialise the product or some of its components?

Did you design the lower structure to eliminate the frame?

Did you design only one frame from module to module?

Did you design an array frame to eliminate the single module frame?

Did you design to integrate the frame with the support structure?

Did you increase the cell size to reduce connection between each other, without compromising the efficiency of the system?

Did you prefer square cells (not smoothed) to optimise the use of material?

Did you avoid over-sized dimensions?

Did you apply ribbed to the base and to the hard-sheet to increase structural stiffness and to reduce weight?

Did you avoid extra components with little functionality?

Minimise Materials Consumption - PV Module

163


Did you select processes that reduce scraps and discarded materials during production?

Did you engage simulation systems to optimise transformation processes?

Did you avoid packaging?

Did you choose efficient transport systems as inflatable or angular packaging?

Did you use only one packaging for more modules?

Did you apply materials only where absolutely necessary?

Did you design for more efficient consumption of operational materials?

Did you design to be self-cleaning?

Did you design the frame to drain water?

Did you design a system as windscreen wiper to clean the module surface?

164


Did you design self-cleaning systems linked to sensors of dirt?

Did you design for more efficient supply of raw materials?

Did you design for more efficient use of maintenance materials?

Did you design systems for consumption of passive materials (water, wind)?

Did you design for cascading recycling systems?

Did you facilitate the person managing maintanance to reduce materials consumption?

Did you design an anchoring system to facilitate maintenance?

Did you design module with an integrated cleaning system?

Did you engage digital support systems with dynamic configuration?

Did you design a monitoring system to identify precise dirt areas?

165


Did you design dynamic materials consumption for different operational stages?

Did you engage sensors to adjust materials consumption according to differentiated operational stages?

Did you reduce resource consumption in the product’s default state?

NR. OF ANSWERS

PERCENTAGE (nr. applicable checklists / nr. answers x 100)

166


Did you design inner components to optimise space and use less material?

Did you digitalise the product or some of its components, sending the data directly to mobile phone in order to replace the front display?

Did you minimise case material content to enhance fitting and to reduce empty spaces?

Did you apply ribbed to the case to increase structural stiffness?


Did you select processes that reduce scraps and discarded materials during production of the case and the integrated circuits?


Did you design case to be stackable and optimised for transport?


Did you design the inverter to be mounted in the location of final use?

Minimise Materials Consumption - Inverter

167


Did you design the package to be part (or to become a part) of the product?


Did you design the case with an anti-dust material?

Did you optimise shapes, grids and holes?


Did you design the case to be easily removable to remove inner dust?

NR. OF ANSWERS


168


Did you dematerialise the product or some of its components?

Did you design the support structure integrated with the module frame and with the the roof?


Did you apply ribbed to the structure to increase structural stiffness?


Did you select processes that reduce scraps and discarded materials during production?



Did you choose efficient transport systems with minimal (or not present) packaging?

Did you optimise packaging for more support structures?

Minimise Materials Consumption - Support Structure

169




Did you design the structure with a shape to avoid store of dirt or water?



Did you design systems for consumption of passive materials (water, wind)?



Did you design an anchoring system to facilitate maintenance?

Did you set the product’s default state at minimal materials consumption?

170


Did you engage digital support systems with dynamic configuration?

Did you design a monitoring system to identify precise dirt areas?

Did you design dynamic materials consumption for different operational stages?

Did you engage sensors to adjust materials consumption according to differentiated operational stages?

Did you reduce resource consumption in the product’s default state?

NR. OF ANSWERS


171




Did you select processes that reduce scraps and discarded materials during production of the electric cables?



Did you choose efficient transport systems using rubber bands to hold electric cables toghether?

Did you design the package to be part (or to become a part) of the product?


Did you design cover to protect electric cables?


Minimise Materials Consumption - Electric Installation

172



Did you design systems for consumption of passive materials?



NR. OF ANSWERS


173

Optimisation of Product Lifespan - PV Module


Did you reduce overall number of components?

Did you simplify products?

Did you eliminate weak liaisons?

Did you enable and facilitate software upgrading?

Did you design reprogrammable monitoring systems for the surplus energy management?

Did you enable and facilitate hardware upgrading?

Did you design the module in order to replace current cells with more efficiency cells in the future?

Did you design modular and dynamically configured products to facilitate their adaptability for changing environments?

Did you design an adaptable module for potential changing of location?

Did you design onsite upgradeable and adaptable module?

174


Did you design complementary tools and documentation for the module upgrading and adaptation?

Did you simplify access and disassembly to components to be maintained: in particular pv cells and potential movement parts?

Did you avoid narrow slits and holes to facilitate access for cleaning?

Did you prearrange and facilitate the substitution of short-lived components?

Did you equip the module with easily usable tools for maintenance as windscreen wiper, water jet or air jet?

Did you equip products with diagnostic and/or auto-diagnostic systems for maintainable components?

Did you design products for easy on-site maintenance: anchoring system, sensor of dirt?

Did you design complementary maintenance tools and documentation?

Did you design products that need less maintenance: less parts, easy shapes, long-lived materials?

Did you arrange and facilitate disassembly and re-attachment of easily damageable components as pv cells?

175


Did you design components according to standards to facilitate substitution of damaged parts in order to be always compatible?

Did you equip products with automatic damage diagnostics system?

Did you design a sensor that identify the precise broken pv cell with a communication system connected directly to the technical assistance?

Did you design the module for facilitated onsite repair?

Did you design complementary repair tools, materials and documentation for pv cells?

Did you increase the resistance of easily damaged and expendable components as pv cells?

Did you arrange and facilitate access and removal of retrievable components as pv cells?

Did you design modular and replaceable module in order to replace it in different places?

Did you design components according to standards to facilitate replacement?

Did you design re-usable auxiliary parts?

176


Did you design the re-usable packaging: replace cardboard with inflatable material?

Did you design and facilitate removal and substitution of pv cells?

Did you design structural parts that can be easily separated from external/visible ones?

Did you provide easier access to pv cells to be re-manufactured?

Did you calculate accurate tolerance parameters for easily expendable connections?

Did you design for excessive use of material for easily deteriorating surfaces?

Did you design the module using a solar glass easy to re-treating on the surface?

NR. OF ANSWERS


177

Optimisation of Product Lifespan - Inverter


Did you reduce overall number of components, designing a monocomponent case?

Did you simplify products designing a case with a linear shape?

Did you enable and facilitate energy management software upgrading?

Did you design modular and dynamically configured inverter to facilitate its adaptability for changing environments?

Did you design onsite upgradeable and adaptable inverter?

Did you design complementary tools and documentation for the inverter adaptation?

Did you simplify access and disassembly to the case and the grid to be maintained?

Did you avoid narrow slits and holes to facilitate access for cleaning the case, the grid and the wall?

Did you prearrange and facilitate the substitution of short-lived components as capacitor?

Did you equip the product with easily usable tools for maintenance?

178



Did you design a system that alerts the user to possible malfunctioning: capacitor wear, overuse, over and under voltage, ultrasonic vibrations?

Did you design products for easy on-site maintenance?

Did you design an easy access to capacitors and integrated circuits?


Did you design products that need less maintenance especially on the capacitors?

Did you arrange and facilitate disassembly and re-attachment of easily damageable parts as capacitors?

Did you design components according to standards to facilitate substitution of damaged parts?

Did you equip products with automatic damage diagnostics system with a sensor that identifies the problem on capacitor or integrated circuit and transmits data to technical assistance?

Did you design inverter for facilitated onsite repair?

179


Did you design complementary repair tools, materials and documentation?

Did you increase the resistance of easily damaged and expendable internal parts?

Did you arrange and facilitate access and removal of retrievable components as integrated circuit and printed wiring board?

Did you design modular and replaceable inverter in order to replace it in different places, working on the rear joints?



Did you design and facilitate removal and substitution of easily expendable inverter components as capacitors?


Did you provide easier access to inverter components to be re-manufactured?


180


NR. OF ANSWERS


181

Optimisation of Product Lifespan - Support Structure






Did you design the support structure in order to replace each part indipendently?


Did you design an adaptable support structure for potential changing of location?

Did you design onsite upgradeable and adaptable support structure?

Did you design complementary tools and documentation for the support structure upgrading and adaptation?

Did you simplify access and disassembly to components to be maintained, in particular possible movement parts?

182




Did you equip the module with easily usable tools for maintenance as windscreen wiper, water jet or air jet?


Did you design products for easy on-site maintenance: anchoring system, sensor of dirt?


Did you design products that need less maintenance: less parts, easy shapes, long-lived materials?

Did you arrange and facilitate disassembly and re-attachment of easily damageable components of the support structure?


Did you equip products with automatic damage diagnostics system?

183


Did you design a sensor that identify the precise broken part of the structure, with a communication system connected directly to the technical assistance?

Did you design support structure for facilitated onsite repair?


Did you increase the resistance of easily damaged and expendable components as structure parts more exposed to the bad weather?

Did you arrange and facilitate access and removal of all parts of the support structure?

Did you design modular and replaceable structure in order to replace it in different places?



Did you design the support structure for secondary use, not only for one kind of pv system?

Did you design and facilitate removal and substitution of easily expendable components?

184



Did you provide easier access to support structure parts to be re-manufactured?


Did you design for excessive use of materials in places more subject to deterioration?

Did you design for excessive use of material for easily deteriorating surfaces?

Did you design the support structure using an aluminium easy to re-treating on the surface?

NR. OF ANSWERS


185

Optimisation of Product Lifespan - Electric Installation






Did you design the electric installation in order to replace current cables with more efficiency cables in the future?


Did you design an adaptable electric installation for potential changing of location?

Did you design onsite upgradeable and adaptable electric installation?

Did you design complementary tools and documentation for the electric cables adaptation?

Did you simplify access and disassembly to electric components to be maintained?

186




Did you equip the product with easily usable tools for maintenance?


Did you design a system that alerts the user to possible malfunctioning: cables wear, overuse, over and under voltage, ultrasonic vibrations?

Did you design products for easy on-site maintenance?

Did you design an easy access to every electric cable?


Did you design products that need less maintenance?

Did you arrange and facilitate disassembly and re-attachment of easily damageable parts?

187



Did you equip products with automatic damage diagnostics system with a sensor that identifies the problem on a specific cable and transmits data to technical assistance?

Did you design electric installation for facilitated onsite repair?


Did you increase the resistance of easily damaged and expendable cables?

Did you arrange and facilitate access and removal of retrievable cables?

Did you design modular and replaceable electric installation in order to replace it in different places?


Did you design the re-usable packaging: replace cardboard with rubber bands?

Did you design and facilitate removal and substitution of easily expendable cables?

188



Did you provide easier access to electric installation components to be re-manufactured?


NR. OF ANSWERS


189

Minimising Toxic Emission - PV Module


Did you avoid toxic or harmful materials for product components?

Did you minimise the hazard of toxic and harmful materials?

Did you avoid materials that emit toxic or harmful substances during pre-production?

Did you avoid additives that emit toxic or harmful substances?

Did you avoid technologies that process toxic and harmful materials?

Did you avoid toxic or harmful surface treatments?

Did you design products that do not consume toxic and harmful materials?

Did you avoid materials that emit toxic or harmful substances during usage?

Did you avoid materials that emit toxic or harmful substances during disposal?

Did you select energy resources that reduce dangerous emissions during pre-production and production?

190


Did you select energy resources that reduce dangerous emissions during distribution?

Did you select energy resources that reduce dangerous emissions during usage?

Did you select energy resources that reduce dangerous residues and toxic and harmful waste?

NR. OF ANSWERS


191

Minimising Toxic Emission - Inverter












192





NR. OF ANSWERS


193

Minimising Toxic Emission - Support Structure












194





NR. OF ANSWERS


195

Minimising Toxic Emission - Electric Installation












196





NR. OF ANSWERS


197

Improve Lifespan of Materials - PV Module


Did you arrange and facilitate recycling of materials in components with lower mechanical requirements?

Did you facilitate disassembly of copper cables and frame?

Did you facilitate disassembly and transport of pv cells?

Did you select materials that easily recover after recycling the original performance characteristics, paying particular attention to different kinds of recyclable pv cells?

Did you avoid composite materials or, when necessary, choose easily recyclable ones?

Did you engage geometrical solutions like ribbing to increase polymer stiffness instead of reinforcing fibres?

Did you prefer thermoplastic polymers to thermosetting?

Did you design considering the secondary use of the materials once recycled?

Did you design in compliance with product retrieval system?

Did you minimise cluttering and improve stackability of discarded products?

198


Did you design for the compressibility of discarded products?

Did you design modules to be stackables and to optimise space during transport?

Did you provide the user with information about the disposing modalities of the product or its parts using a digital codification with recycling mode description?

Did you codify different materials to facilitate their identification?

Did you provide additional information about the material’s age, number of times recycled in the past and additives used?

Did you define time of use of the module to give informations about recycle?

Did you indicate the existence of toxic or harmful materials, especially inside pv cell?

Did you use standardised materials identification systems?

Did you arrange codifications in easily visible places?

Did you integrate functions to reduce the overall number of materials and components: integration between frame and support structure?

199


Did you avoid codifying after component production stages?

Did you use monomaterial strategy: only one material per product or per sub-assembly?

Did you use only one material, but processed in sandwich structures?

Did you use compatible materials (that could be recycled together) within the product or sub-assembly?

Did you use, for joining, the same or compatible materials as in components (to be joined)?

Did you avoid unnecessary coating procedures?

Did you avoid irremovable coating materials?

Did you facilitate removal of coating materials?

Did you use coating procedures that comply with coated materials?

Did you avoid adhesives or choose ones that comply with materials to be recycled?

200


Did you prefer the dyeing of internal polymers, rather than surface painting?

Did you avoid using additional materials for marking or codification?

Did you mark and codify materials during moulding?

Did you codify polymers using lasers?

Did you select high energy materials for products that are going to be incinerated?

Did you avoid materials that emit dangerous substances during incineration?

Did you avoid additives that emit dangerous substances during incineration?

Did you facilitate the separation of materials that would compromise the efficiency of combustion (with low energy value)?

NR. OF ANSWERS


201

Improve Lifespan of Materials - Inverter


Did you arrange and facilitate recycling of materials in components with lower mechanical requirements using a polymeric case?

Did you simplify disassembly of the case?

Did you simplify disassembly of internal components as capacitors, integrated circuits and printed wiring boards?

Did you arrange and facilitate recycling of materials in components with lower aesthetical requirements?

Did you arrange and facilitate energy recovery from materials throughout combustion?

Did you select materials that easily recover after recycling the original performance characteristics?




Did you prefer heat-proof thermoplastic polymers to fireproof additives?

202




Did you minimise overall weight?


Did you design for the compressibility of discarded products as case?

Did you design to optimise occupied space of single parts during transport phase?




Did you define time of use of the inverter to give informations about recycle?

203


Did you indicate the existence of toxic or harmful materials as inside the printed wiring board?




Did you integrate functions to reduce the overall number of materials and components: integration between printed wiring boards and isolation parts?


Did you design case with same material of isolation parts?

Did you use only one material, but processed in sandwich structures?


Did you avoid unnecessary coating procedures as stickers or labels?

204










NR. OF ANSWERS


205

Improve Lifespan of Materials - Support Structure



Did you facilitate disassembly of the aluminium from the other materials?

Did you arrange and facilitate energy recovery from materials throughout combustion?


Did you recover more aluminium that which is possible?






206




Did you design for the compressibility of discarded products as aluminium planks, clamps, hooks?


Did you codify different materials to facilitate their identification: in particular separate metals from polymers?


Did you define time of use of the module to give informations about recycle?




207


Did you integrate functions to reduce the overall number of materials and components: integration between frame and support structure?



Did you use, for joining, the same or compatible materials as in components (to be joined): utilize steel also where polymer is usually used?

Did you design removable junctions?

Did you avoid unnecessary coating procedures as stickers or labels?





208






Did you select high energy materials for products that are going to be incinerated?

Did you avoid materials that emit dangerous substances during incineration?

Did you avoid additives that emit dangerous substances during incineration?

Did you facilitate the separation of materials that would compromise the efficiency of combustion (with low energy value)?

NR. OF ANSWERS


209

Improve Lifespan of Materials - Electric Installation



Did you simplify disassembly of cables?









210


Did you design for the compressibility of discarded products?

Did you design to optimise occupied space of single parts during transport phase?




Did you define time of use of the inverter to give informations about recycle?

Did you indicate the existence of toxic or harmful materials?




211


Did you integrate functions to reduce the overall number of materials and components?


Did you avoid unnecessary coating procedures?








212



NR. OF ANSWERS


213

Minimising Energy Consumption - PV Module


Did you select materials with low energy intensity?

Did you utilize recycled aluminium?

Did you looking for materials and processes with lower energy consumption than silicon during production phase?

Did you select processing technologies with the lowest energy consumption possible?

Did you design compact photovoltaic module with high storage density?

Did you scale down the product weight?

Did you scale down the packaging weight?

Did you decentralise activities to reduce transportation volumes?

Did you select local material and energy sources?

Did you design attractive products for collective use?

214


Did you design sharing networks, energy surplus, decentralized systems for collective use?

Did you design new communication strategies?

Did you design to reduce loss of the system due to wear and environmental causes?

Did you design for energy-efficient maintenance?

Did you design manual systems for cleaning and mainenance, manageable from final user?

Did you engage highly efficient energy conversion systems?

Did you looking for the most advanced technologies with more efficient systems?

Did you design/engage highly efficient power transmission?

Did you design for maximum operating temperature?

Did you design taking into account the balance of system (BOS)?

215


Did you use highly caulked materials and technical components?

Did you design the module using shapes and material that allow dispersion of the heat to maintain system efficiency?

Did you design energy recovery systems, also to replace batteries?

Did you design energy-saving systems?

Did you design to avoid the stand-by, in case of an automation system for movement?

Did you engage digital dynamic support systems to control energy expenditure and manage in-grid exchange?

Did you design dynamic energy consumption systems for differentiated operational stages?

Did you engage sensors to adjust consumption during differentiated operational stages?

Did you design a monitoring system to identify possible inefficiency?

Did you equip machinery with intelligent power-off utilities?

216


Did you design the possibility to switch off the system?

NR. OF ANSWERS


217

Minimising Energy Consumption - Inverter



Did you minimise the use of copper, aluminum and the others electronic components with a large energy waste?

Did you minimise energy consumption during transportation and storage?

Did you design compact inverter with high storage density?




Did you design sharing networks, energy surplus, decentralized systems for collective use (an inverter for more users)?



218





Did you design the inverter taking into account materials and shapes that allow dispersion of the heat in order to maintain the efficiency?


Did you design an on/off system activated manually or automatically only during the real use of energy?


Did you design dynamic energy consumption systems for differentiated operational stages (in relation with different power demands)?



219


Did you design the possibility to switch off the inverter (instead of stand-by)?

NR. OF ANSWERS


220

Minimising Energy Consumption - Support Structure



Did you utilize recycled aluminium?

Did you select processing technologies with the lowest energy consumption possible?

Did you design compact support structure with high storage density?



Did you decentralise activities to reduce transportation volumes?

Did you select local material and energy sources?



221


Did you design to reduce loss of the support structure due to wear and environmental causes?




Did you design the module using shapes and material that allow dispersion of the heat to maintain system efficiency?

Did you design energy recovery systems, also to replace batteries?


Did you design to avoid the stand-by, in case of an automation system for movement?

NR. OF ANSWERS


222

Minimising Energy Consumption - Electric Installation



Did you minimise the use of copper and the others electronic components with a large energy waste?

Did you engage efficient machinery?

Did you minimise energy consumption during transportation and storage?

Did you design compact cables with high storage density?





Did you design for energy-efficient operational stages?

223











Did you design dynamic energy consumption systems for differentiated operational stages (in relation with different power demands)?

224




NR. OF ANSWERS


225

Renewable & Bio-Compatible Resources - PV Module


Did you use renewable materials?

Did you avoid exhaustive materials?

Did you use residual materials of production processes?

Did you use retrieved components from disposed products?

Did you use recycled materials, alone or combined with primary materials?

Did you use bio-degradable materials?

Did you use renewable energy resources?

Did you engage the cascade approach?

Did you select energy resources with high second-order efficiency?

NR. OF ANSWERS


226

Renewable & Bio-Compatible Resources - Inverter











NR. OF ANSWERS


227

Renewable & Bio-Compatible Resources - Support Structure











NR. OF ANSWERS


228

Renewable & Bio-Compatible Resources - Electric Installation











NR. OF ANSWERS


229

Design for Disassembly - PV Module


Did you prioritise the disassembly of toxic and dangerous components or materials?

Did you prioritise the disassembly of components or materials with higher economic value?

Did you prioritise the disassembly of more easily damageable components?

Did you engage modular structures?

Did you divide the product into easily separable and manipulatable sub-assemblies?

Did you minimise overall dimensions of the product?

Did you minimise hierarchically dependent connections between components?

Did you minimise different directions in the disassembly route of components and materials?

Did you increase the linearity of the disassembly route?

Did you engage a sandwich system of disassembly with central joining elements?

230


Did you avoid difficult-to-handle components?

Did you avoid asymmetrical components, unless required?

Did you design leaning surfaces and grabbing features in compliance with standards?

Did you arrange leaning surfaces around the product’s centre of gravity?

Did you design for easy centring on the component base?

Did you avoid joining systems that require simultaneous interventions for opening?

Did you minimise the overall number of fasteners?

Did you minimise the overall number of different fastener types (that demand different tools)?

Did you avoid difficult-to-handle fasteners?

Did you design accessible and recognisable entrances for dismantling?

231


Did you design accessible and controllable dismantling points?

Did you employ two-way snap-fit?

Did you employ joints that are opened with common tools?

Did you employ joints that are opened with special tools, when opening could be dangerous?

Did you design joints made of materials that become reversible only in determined conditions?

Did you use screws with hexagonal heads?

Did you prefer removable nuts and clips to self-tapping screws?

Did you use screws made of materials compatible with joint components, to avoid their separation before recycling?

Did you use self-tapping screws for polymers to avoid using metallic inserts?

Did you avoid rivets on incompatible materials?

232


Did you avoid staples on incompatible materials?

Did you avoid additional materials while welding?

Did you weld with compatible materials?

Did you prefer ultrasonic and vibration welding with polymers?

Did you avoid gluing with adhesives?

Did you employ easily removable adhesives?

Did you design thin areas to enable the taking off of incompatible inserts, by pressurised demolition?

Did you co-design cutting or breaking paths with appropriate separation technologies for incompatible materials separation?

Did you equip the product with a device to separate incompatible materials?

Did you employ joining elements that allow their chemical or physical destruction?

233


Did you make the breaking points easily accessible and recognisable?

Did you provide the products with information for the user about the characteristics of crushing separation?

NR. OF ANSWERS


234

Design for Disassembly - Inverter












235












236












237












238




NR. OF ANSWERS


239

Design for Disassembly - Support Structure












240












241












242












243




NR. OF ANSWERS


244

Design for Disassembly - Electric Installation












245












246












247












248




NR. OF ANSWERS


252

This thesis was concluded with the creation of a sustainable design guideline handbook. This document will be available in copy left, for everyone to access. This handbook is intended for designer or companies that want to adopt a LCD approaches or that want to reduce the environmental burden of their products. It contains the seven design priorities and a checklist. After a brief introduction of the LCD and LCA concepts and methodologies, the priorities are explained with the help of graphics. The structure is: priority and component for each of the parts of the PV system (PV module, inverter, support structure, electric installation). After the description that points the phases or materials with high environmental impact the guidelines follow. At the end of the book, there is checklist that tries to quantify the design achievements.

The future step for a designer that needs to project a PV system with lower environmental impact is to redesign the product following the impact reduction design priorities.As some of the design choice might have unexpected environmental impacts it is advised to perform a second LCA and to calculate new priorities to fully understand the changes. Only at this point the redesign can be considered finished. Even though, technological advances can develop new strategies or new material or processes that can further the redesign process and consequentially reduce more the environmental impact.

7.1 Future Steps

253

Despite of the critics brought to the LCA methodologies like the complexity and the scientific unreliability, looking at all the life cycles of a product as well as quantifying the environmental impact can switch on a light on new design approaches. The scope of the assessment was not to compare the results with other projects, instead the study should be considered relevant as a starting point to compare results before and after redesign of the same PV system.

Therefore, identifying the component with the highest LCA impact, which is the PV Module, is pointing out an important design choice as the environmental impact of this component represents 59% of the total, followed by the Inverter, that represents in LCA 22% of the total. The LCA component that ranked third is the Support Structure with 12% of the total, followed by the Electric Installation 7% of the total. The rank is similar also when we start talking about the Strategic Design Priority Identification that shows the priority among the design guidelines.

In the Minimise Materials Consumption which is the strategy with the highest priority, the PV Module ranks first with a value of 1,34pt followed by the Inverter with a value of 0,682pt, Support Structure 0,383pt and Electric Installation 0,223pt. The second priority is Optimisation of Product Lifespan: PV Module (0,803), Inverter (0,292), Support Structure (0,164), Electric Installation (0,095). The sum for the whole system Minimising Toxic Emission strategy ranked third: PV Module (0,426), Inverter (0,39), Support Structure (0,037), Electric Installation (0,237). Improve Lifespan of Materials ranks fourth: PV Module (0,376), Inverter (0,102), Support Structure (0,072), Electric Installation (0,043). Minimising Energy Consumption ranks fifth: PV Module (0,069), Inverter

7.2 Final Remarks

254

(0,045), Support Structure (0,00), Electric Installation (0,00). The last priority is the Renewable & Bio-Compatible Resources strategy: PV Module (0,038), Inverter (0,0015), Support Structure (0,0012), Electric Installation (0,000057).

In conclusion the Minimise Materials Consumption strategy has the highest priority showing that the biggest environmental gain can come from using less material, using lighter materials or more performant ones. A big importance should be given also to Optimisation of the PV System Components Lifespan. The system, in fact, nowadays is guaranteed for 25 years, but, with the help of new technologies, it’s not difficult increase its life until 40 years. The Minimising Toxic Emission has a medium priority beacause the presence of toxic materials in pv cells and printed wiring boards: for this reason it’s important keep attention especially in production and disposal. The Improve Lifespan of Materials strategy is important especially for secondary use, remanufacturing, recycling or energy regain. Minimising Energy Consumption strategy refers to avoid the pv module and inverter losses as much as possible. Renewable and Bio-Compatible Resources strategy points to use of ecofriendly materials and energy sources: this priority is low because many recycled materials are already present in this kind of product.

255

7.3 Acknowledgments

I would first like to thank my thesis tutor Dr. Carlo Arnaldo Vezzoli of the School of Design at Politecnico di Milano. He consistently allowed this paper to be my own work, but steered me in the right the direction whenever he thought I needed it.

I would also like to acknowledge Dr. Carlo Proserpio and Dr. Emanuela Delfino as the co-tutors of this thesis, and I am gratefully indebted to their for their very valuable comments on this thesis. Without their passionate participation and input, the validation survey could not have been successfully conducted.

Finally, I must express my very profound gratitude to my parents and to my friends for providing me with unfailing support and continuous encouragement throughout my years of study and through the process of researching and writing this thesis. This accomplishment would not have been possible without them. Thank you.

Marco Grazia

258

Arranz P., Anzizu M., Vallvé X., et al., “Pv systems with lower environmental impact: new strategies and analysis tool”, 28th European Photovoltaic Solar Energy Conference, 2013.

Federazione Italiana per l’Uso Razionale dell’Energia FIRE, “Impianti eolici e fotovoltaici di piccola taglia: guida tecnica”, 2011.

Fraunhofer Institute for Solar Energy Systems ISE, “Photovoltaics report”, October 2016.

Fthenakis V., Kim H.C., “Photovoltaics: life cycle analyses”, Science Direct, 2011.

Fthenakis V., Kim H.C., Frischknecht R., et al., “Life cycle inventories and life cycle assessments of photovoltaic systems”, International Energy Agency IEA, January 2015.

Garcia Valverde R., Miguel C., Martinez Bejar R, et al., “Life cycle assessment study of a 4.2kWp stand-alone photovoltaic system”, Science Direct, 2009.

Gestore Servizi Energetici GSE, “Rapporto statistico 2014 solare fotovoltaico”, 2014.

Hahne A., Hirn G., “Recycling photovoltaics modules”, BINE Informationsdienst, February 2010.

International Energy Agency IEA, “Technology roadmap, solar photovoltaic energy”, September 2014.

8.1 Bibliography

259

International Energy Agency IEA, “Trends 2014 in photovoltaic applications”, September 2014.

Jungbluth N., Stucki M., Flury K., et al., “Life cycle inventories of photovoltaic”, Swiss Federal Office of Energy SFOE, September 2012.

Latunussa C., Ardente F., Blengini G.A., Mancini L., “Life cycle assessment of an innovative recycling process for crystalline silicon photovoltaic panels”, Science Direct, 2016.

Marano A., “Design solare”, Gangemi Editore, 2012.

Mazzarini V., “Valutazioni ambientali del ciclo di vIta di un impianto fotovoltaico”, Università di Bologna, 2010.

Miu I.M., “The eco-efficient design of small hydropower stations”, Politecnico di Milano, 2016.

Mohanty P., Muneer T., Gago E.J., Kotak Y., “Solar radiation fundamentals and pv system components”, Springer International Publishing, 2016.

Palanov N., “Life cycle assesment of photovoltaic system”, Lund University, 2014.

Payet J., Evon B., Sié M., et al., “Methodological framework for assessing the environmental impacts of pv systems using the LCA method”, Agence de l’environnement et de la maîtrise de l’énergie ADEME, 2011.

260

Peng J., Lu L., Yang H., “Review on life cycle assessment of energy payback and green house gas emission of solar photovoltaic systems”, Science Direct, 2012.

Vezzoli C., Ceschin F., Cortesi S., “Metodi e strumenti per il life cycle design. Come progettare prodotti a basso impatto ambientale”, Maggioli Editore, 2009

Vezzoli, C., Manzini, E., “Design for Environmental Sustainability”, Springer, 2008.

Vezzoli, C., Sciama, D., “Life Cycle Design: from general methods to product type specific guidelines and checklists: a method adopted to develop a set of guidelines/checklist handbook for the eco-efficient design of NECTA vending machines”, Journal of Cleaner Production, 2006.

Wade A., Heath G., “End of life management solar photovoltaic panels”, International Energy Agency IEA, June 2016.

261

8.2 Sitography

http://www.apva.org.au/pros-and-cons-of-photovoltaics-or-solar-panels

http://www.automation.com/automation-news/article/the-top-five-things-that-cause-inverter-failure

http://www.britannica.com/science/photovoltaic-effect

http://www.corriere.it/ambiente/14_gennaio_16/pannelli-solari-smaltimento-vera-miniera-1e349a18-7ebf-11e3-a051-6ffe94d9e387.shtml

http://www.edilportale.com/prodotti/rossato-group/pannello-solare-compatto/fino_112836.html

http://energyinformative.org/best-solar-panel-monocrystalline-polycrystalline-thin-film/

http://www.ferraloro.it/article/moduli-fotovoltaici-frameless

https://www.fotovoltaiconorditalia.it/idee/dimensioni-pannelli-fotovoltaici-2

http://www.fsec.ucf.edu/en/consumer/solar_electricity/basics/cells_modules_arrays.htm

http://www.greenrhinoenergy.com/solar/technologies/pv_energy_yield.php

http://www.infopannellisolari.com/dati/provincia.php?codice=13

http://www.lavorincasa.it/riciclare-pannelli-fotovoltaici/

http://www.lavoripubblici.it/news/2016/04/ENERGIA/Lo-smaltimento-e-il-riciclo-dei-pannelli-fotovoltaici-in-Italia_16830.html

http://www.leonics.com/support/article2_12j/articles2_12j_en.php

http://midwestgreenenergy.com/howdoespvwork.html

262

http://www.nanocreate.it/prodotti/prodotti-per-il-building/glas-solar-plus-idrofilo-fotocatalitico/

http://www.nef.org.uk/knowledge-hub/solar-energy/types-of-photovoltaic-pv-cells

http://www.renewableenergyworld.com/ugc/blogs/2012/12/advantages-and-disadvantages-of-solar-photovoltaic-quick-pros-and-cons-of-solar-pv.html

http://www.riciclaggiocavielettrici.it/azienda.htm

http://www.solardirect.com/pv/pvbasics/pvbasics.htm

https://en.wikipedia.org/wiki/Solar_power_in_Italy

https://en.wikipedia.org/wiki/Growth_of_photovoltaics

263

8.3 Image Sources

Fig.1.1 - http://www.e-gazette.it/sites/default/files/images/2016/dec/12/pannelli-fotovoltaici.jpg

Fig.1.5 - http://www.solarbestpractice.com/wp-content/uploads/2015/06/Worldwide-Photovoltaic-Growth-capacity.jpg

Fig. 3.1 - Gestore Servizi Energetici - Rapporto statistico 2014 solare fotovoltaico

Fig. 3.3a - http://www.aes-tunisie.com/userfiles/image/pv%20grid%20connected.bmp

Fig. 3.3b - http://www.permaculturenews.org/images/Stand-alone-solar.jpg

Fig. 3.4.1 - http://www.seia.org/sites/default/files/pv-cell.jpg

Fig. 3.4.2a - https://images.angelpub.com/2015/13/29942/1.png

Fig. 3.4.2b - https://phlebasblog.files.wordpress.com/2014/09/silicon-to-cell.png

Fig. 3.4.3 - http://www.usolarshop.co.uk/images/XL/power-one-pvi-30-outd-inverter.jpg

Fig. 3.4.4 - http://www.sflex.com/htdocs/images/sflex/sflex_xl_schraegdachgestell.jpg

All the images, graphs and tables not in the list are personally designed and realized by the author.

Documents

The Eco-Efficient Design of Small Photovoltaic …...School of Design Master of Science in Design and Engineering The Eco-Efficient Design of Small Photovoltaic System A Handbook of