Mini Project Renewable

8/2/2019 Mini Project Renewable

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INTRODUCTION

Solar resources

Solar radiation, often called the solar resource, is a general term for the electromagnetic radiation

emitted by the sun. Solar radiation can be captured and turned into useful forms of energy, such asheat and electricity, using a variety of technologies. However, the technical feasibility and

economical operation of these technologies at a specific location depends on the available solar

resource. The Earth receives 174 petawatts of incoming solar radiation (insolation) at the upper

atmosphere. Approximately thirty percent is reflected back to space while the rest is absorbed by

clouds, oceans and land masses. The total solar energy absorbed by Earth's atmosphere, oceans and

land masses is approximately 3,850,000 exajoules (EJ) per year. The amount of solar energy

reaching the surface of the planet is so vast that in one year it is about twice as much as will ever be

obtained from all of the Earth's non-renewable resources of coal, oil, natural gas, and mined uranium

combined. Solar energy can be harnessed in different levels around the world. Depending on a

geographical location the closer to the equator the more "potential" solar energy is available.

Figure 1: Solar radiation

Solar Energy Can Be Used for Heat and Electricity

When converted to thermal (or heat) energy, solar energy can be used to:

Heat waterfor use in homes, buildings, or swimming pools Heat spacesinside homes, greenhouses, and other buildings Heat fluidsto high temperatures to operate a turbine to generate electricity

Solar energy can be converted to electricity in two ways:

Photovoltaic (PV devices) or solar cellschange sunlight directly into electricity. Individual PV cells are grouped into panels and

arrays of panels that can be used in a wide range of applications ranging from single small

cells that charge calculator and watch batteries, to systems that power single homes, to large

power plants covering many acres.


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Solar Thermal/Electric Power Plantsgenerate electricity by concentrating solar energy to heat a fluid and produce steam that is

used to power a generator

THEORY

Theory of Solar Photovoltaic/Cells

Photovoltaic Cells Convert Sunlight into Electricity

A photovoltaic cell, commonly called a solar cell or PV, is the technology used to convert solar

energy directly into electrical power. A photovoltaic cell is a nonmechanical device usually made

from silicon alloys.

Figure 2: PV cell

Photons Carry Solar Energy

Sunlight is composed of photons, or particles of solar energy. These photons contain various

amounts of energy corresponding to the different wavelengths of the solar spectrum. When photons

strike a photovoltaic cell, they may be reflected, pass right through, or be absorbed. Only the

absorbed photons provide energy to generate electricity. When enough sunlight (energy) is absorbed

by the material (a semiconductor), electrons are dislodged from the material's atoms. Special

treatment of the material surface during manufacturing makes the front surface of the cell more

receptive to free electrons, so the electrons naturally migrate to the surface.


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The Flow of Electricity

When the electrons leave their position, holes are formed. When many electrons, each carrying a

negative charge, travel toward the front surface of the cell, the resulting imbalance of charge between

the cell's front and back surfaces creates a voltage potential like the negative and positive terminals

of a battery. When the two surfaces are connected through an external load, such as an appliance,electricity flows.

How Photovoltaic Systems Operate

The photovoltaic cell is the basic building block of a photovoltaic system. Individual cells can vary

in size from about 0.5 inches to about 4 inches across. However, one cell only produces 1 or 2 watts,

which isn't enough power for most applications. To increase power output, cells are electrically

connected into a packaged weather-tight module. Modules can be further connected to form an array.

The term array refers to the entire generating plant, whether it is made up of one or several thousand

modules. The number of modules connected together in an array depends on the amount of power

output needed.

MINI PROJECT (SOLAR ENERGY RESEARCH)

OBJECTIVES

A mini project of solar energy is performed as a research to investigate the process of solar energy

conversion into electrical power. The objectives of this mini project are:

To design, construct and converting of energy of solar resource from renewable energy whichis the sun.

To produce the output (electrical power) from the solar panel. To display and measure the output from the solar panel.

METHODOLOGY

The Mini Project Overview

Design circuit Produce hardware

Record data

(output/display

from hardware)

Produce results and

analysis

Record data (Measureoutput using

multimeter)


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The solar mini project is performed by using the main element in converting solar energy into

electrical power, which is the solar panel. The solar panel used (shown in Figure 3) is able to produce

maximum voltage of 18V, 0.3A current, 5W power.

Figure 3: Solar panel

The other part in this solar mini project is the hardware for displaying output, which is the electrical

power from the solar panel. Various electronics components are assembled in a circuit in order to

construct a hardware which can display the output of solar energy in form of electric voltage and

current. The following components were used:

1. 7805 voltage regulator2. 16V 1000F capacitors3. 3V dc motor4. Bulbs (types: 2.5V and 3.8V)5. LEDs6. Resistors7. Wire phone charger

The figure below showed the circuit of the hardware:

Figure 4: The hardware for displaying output


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Circuit Diagram of Solar Mini Project

Figure 5: Circuit diagram

Explanation

The solar panel produces maximum voltage and current of 18V, 0.3 Amp. However the components

in the circuit which are motor, bulbs and LEDs require below 18V to making them work, as well as

the phone charger. Mostly mobile phones are charged in range of 3V to 6V and the maximum current

is 1 Amp. In other words, if the components in circuit are still using supply 18V from the solar panel,

they may blow or explode because of overvoltage. The 7805 voltage regulator is very important in

the circuit to regulate and step down the voltage as well as the current. The regulator will produces

maximum voltage of 5V and for the current is 0.4 Amp. Two capacitors which are connected at the

voltage regulator is function as filters to remove voltage and current distortion. The components

which are motor, bulbs, LEDs and phone charger are not connected directly to the power source of

solar panel. There are switches in between these components and solar panel. The connection of

components to solar panel simultaneously can cause the draws power from solar panels will take

place with a lot, and causing the power is not enough to be distributed to all components.


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RESULTS

The data collected at different times, from at 9am to 5pm:

Time Outputvoltage (V)

from solar

panel

Outputcurrent (A)

from solar

panel

Energy consumption at the componentsMotor speed

(fast/slow)

Bulb

brightness

(bright/

dim)

LED

brightness

(bright/

dim)

Phone

charger

(charge/not

charge)

9am 10.06 0.10 slow dim dim Not charge

10am 14.62 0.15 slow dim dim Not charge

11am 18.53 0.23 Fast Bright Bright Charge

12pm 19.47 0.28 Fast Bright Bright Charge



3pm 16.15 0.16 Fast Bright Bright Charge4pm 14.30 0.14 Slow Dim Dim not charge

5pm 13.00 0.12 Slow Dim Dim Not charge

Table 1: Results

ANALYSIS

Based on the table 1, we can see that the output varies from time to time. If the voltage high, the

current also high and the motor speed rotates fast while bulb and LED brightness is bright and the

phone charger is charging. If the voltage low, the current also low and the motor speed rotates slow

while bulb and LED brightness is dim and the phone charger is not charging. The the performance of

functionality of these components are depend on the voltage produced by the solar panel.

DISCUSSIONS

From the result obtained, the voltage and current output are varies from time to time. It is because of

the brightness of the sunlight. The peak of the brightness of the sunlight as we can see is around

12pm till 1pm because the output power that were produced are the highest. So, we can say that thebrighter the sunlight, the more output power that will produced.

However, studies have shown that the output voltage and current from solar panel can be increased

by the using of boost converter circuit. A boost converter is a DC to DC converter with an output

voltage greater than the source voltage. A boost converter is sometimes called a step-up converter

since it steps up the source voltage. Since power ( ) must be conserved, the output

current is lower than the source current. Besides, there is also some other ways to increase the output

power from solar panel, such as the application of joule thief circuit.


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As for a consistent power supply for a long time, the battery is perfectly to be used with the solar

panel. Without batteries to store energy, we would only have power when the sun was shining. Solar

energy is equally not available on cloudy days and during the nighttime, so stored energy must be

available to compensate for the loss of sunlight.

CONCLUSIONS

Solar energy is a clean power source which does not pollute the evironment. The sun is a great

energy source and it will never finish even we used too much of energy. Some solar system works

even if sun does not shine because of the evacuated heaters. Eventhough solar energy can be found

easily, but the cost to make the system is expensive. So, the used of solar energy are not too

comprehensive. In Malaysia, this kind of renewable energy can be found easily because the stable

weather through the year. From this experiment, we know that the solar energy can produce a high

power output based on the how many cell are used in a panel.

Advantages and Disadvantages of Solar Energy:

Solar advantages

1. Clean power source, it does not pollute the environment! Even the manufacturing process

2. Of the solar heater is very gentle against the environment.

3. The sun is a great energy resource, and it will never end.

4. Some solar systems works even if the sun does not shine (evacuated heaters).

Solar disadvantages1. Expensive

2. A solar heater produces most energy when we do not need it, in the summer. But there are ways to

store the energy from the summer to the winter.

Documents

Mini Project Renewable