Design of Micro Grid

EE-570 Renewable Distributed Generation and Storage PROJECT-2

EE570: Renewable Distributed Generation and Storage

DESIGN PROJECT 2

SYSTEM PLANNING/CONVERSION

Converting an Existing Non-Islanded grid section to a fully functional

Microgrid System with the ability to operate in an islanded mode.

Pithapur Mohammed

Cheruvattath Sneha

Tavadia Urvakhsha

Page-1


TABLE OF CONTENTS

TOPIC DESCRIPTION PAGE NO.

Introduction 51. Microgrid Description 62. Technical Design and Configuration 9

2.1 Microgrid infrastructure and operations 9 2.2 Load Characterization 11 2.3 Distributed Energy Resources 15 2.4 Effect of Weather on DERs 22 2.5 Feasibility Study 24 2.6 Electrical Infrastructure 32 2.7 Microgrid Control 38 2.8 Telecommunication Infrastructure 40

3. Assessment of Microgrid’s commercial and financial feasibility 43 3.1 Commercial Viability 43 3.2 Value Proposition 44 3.3 Creating and Delivering Value 47 3.4 Financial Viability 52 3.5 Legal Viability 53

4. Information for benefit cost analysis 57 4.1 Facility and Customer Description 54 4.2 Characterization of DER 57 4.3 Capital Impacts and Ancillary Services 63 4.4 Project Costs 64 4.5 Cost to maintain services during power outage 64 4.6 Services supported by microgrid 64

5. Environmental Considerations 665.1 Environmental Regulations and Standards 665.2 Environmental impacts 68

6. Social Considerations 707. Safety Considerations 708. Health Considerations 719. Ethical Considerations 7110. Sustainability in Power Systems 7211. Conclusion 72

References 73 Appendix A 75

Page-2


LIST OF ALL FIGURES

FIG NO. DESCRIPTION PAGE NO.

1 Proposed microgrid with boundaries 62 Schematic layout of proposed microgrid 93 Microgrid model in ETAP 94 Single line diagram 105 Residential load for single household: Daily, Seasonal and Yearly Profile 116 Consolidated Residential load: Daily, Seasonal and Yearly Profile 117 Critical load Canandaigua School: Daily, Seasonal and Yearly Profile 128 Critical load (Medical Center) + Commercial Load: Daily, Seasonal and

Yearly Profile12

9 Industrial Load: Daily, Seasonal and Yearly Profile 1310 Deferrable Load: Daily, Seasonal and Yearly Profile 1311 Thermal Load: Daily, Seasonal and Yearly Profile 1412 Fuel consumption vs output power curve for CHP used in microgrid 1513 Efficiency vs output power curve for CHP used in microgrid 1714 Available biomass for CHP used in microgrid 1715 Monthly solar global horizontal irradiation data 1816 Monthly average wind speed at Canandaigua 1917 Power curve for 100kW wind turbine 1918 Fuel consumption vs output power curve for hybrid generator 2019 Efficiency vs output power curve for hybrid generators 2020 Storage system using vanadium redox flow 2121 Ice accretion on US Wind power 2222 Cost summary of microgrid during grid connected mode 2423 Monthly average electric production breakdown during grid connected mode 2524 Cash flow of microgrid in grid connected mode 2525 Energy purchased and sold in microgrid in grid connected mode 2626 AC primary load and total load served during grid connected mode 2627 Grid sales and purchase of microgrid during grid connected mode 2728 Unmet electrical load and renewable penetration during grid connected mode 2729 Cost summary of microgrid in islanded mode 2830 Monthly average electric production breakdown during islanded mode 2931 Cash flow of microgrid during islanded mode 2932 Hybrid generator output for islanded mode 3033 Wind turbine power output for islanded mode 3034 AC primary load and total load served in islanded mode 31

Page-3


35 Renewable penetration and unmet electrical load in islanded mode 3136 (a) IEC circuit breaker symbol

(b) Air blast circuit breaker33

37 Puffer type SF6 circuit breaker 3438 Lightning Arrestors 3539 Lightning arrestors installed in distribution tower 3540 Typical layout of an outdoor substation 3641 Output of a static switch 3842 Interoperability in the microgrid 41

LIST OF TABLES

Page-4

Table no. Description Page no.

1 Detailed Analysis of DERs in grid connected mode 242 Detailed Cost Analysis of DERs in islanded mode 283 Diesel consumption chart 614 Natural gas consumption chart 62


CANANDAIGUA MICROGRID DESIGN, CONTROL AND ANALYSIS

Pithapur Mohammed, Cheruvattath Sneha, Tavadia Urvakhsha

Department of Electrical Engineering, State University of New York at Buffalo

Abstract - A microgrid consisting of 250 houses, critical facilities such as VA medical center,

Canandaigua school, Pactiv corporation as well as sheriff’s office is designed and analyzed.

Residential, Industrial, Commercial as well as Thermal Loads are incorporated to visualize an

actual Microgrid. Control strategies and load priority levels are explored. Microgrid – utility

connections and contracts are proposed. Finally, a detailed and thorough feasibility study of the

model is carried out which proves that the microgrid is capable of operating in grid connected as

well as islanded modes.

INTRODUCTION

Department of Energy defines a Microgrid as a group of interconnected loads and distributed

energy resources (DER) with clearly defined electrical boundaries that acts as a single

controllable entity with respect to the grid (and can) connect and disconnect from the grid to

enable it to operate in both grid connected or island mode.

The aim of the project is to develop and simulate a plan to convert a current electrical

distribution grid structure in a Renewable Distributed Generation (DG) and Distributed Storage

(DS) setup. The goal is to design a community grid that improves the local electrical distribution

system performance and resiliency in both a normal operating configuration as well as during

times of electrical grid outages. The local utility seems amenable to this conversion taking place

within their service territory. In addition, the excess generation should have the option/ability to

sell power back to the grid when connected. A careful assessment of an area to be turned into a

Microgrid needs to be performed. Microgrids are essentially self-sustaining, small electric grids

with their own generation resources and internal loads that may or may not be connected to the

larger electric utility “macrogrid”.

The report is organized as follows: Section 1 provides the description of Microgrid, the

location, geography and special features. Section 2 discusses the components and the feasibility

Page-5


study of the Microgrid. Section 3 talks about the commercial and financial aspects while Section

4 produces a benefit cost analysis. Environmental, Social, Economic, Safety and Health

considerations are then discussed. Finally, the report is concluded in Section 10.

1. MICROGRID DESCRIPTION

For this project, the microgrid is built in the city of Canandaigua, a city in Ontario County,

New York, United States. The coordinates of the location are 42º54’21’N 77º16’25’W. As per

the 2010 census, the total population of Canandaigua was 10,545. The Microgrid is spread in an

area of 2.9 mile². The City of Canandaigua is located on the northern end of Canandaigua Lake,

24 miles (39 km) southeast of Rochester and 58 miles (93 km) west of Syracuse. Parts of six

neighboring towns also share the Canandaigua mailing address and 14424 ZIP code.

Page-6


Fig. 1. Proposed Microgrid with boundaries

A. GEOGRAPHY

According to the United States Census Bureau, Canandaigua has a total area of 4.8 square

miles (12.5 km²), of which 4.6 square miles (11.9 km²) is land and 0.2 square mile (0.6 km²)

(4.75%) is water. The city is at the northern end of Canandaigua Lake, in the Finger

Lakes region, the largest wine producing area in New York State. The city is located on U.S.

Route 20 and NY Routes 5 and 21.

Municipality - Canandaigua Municipality is located at City Hall, 2 North Main Street,

Canandaigua, NY 14424, (585)396-5000.

B. MAIN COMPONENTS

The proposed Microgrid has the following components:

1. Canandaigua VA Medical Center

2. Canandaigua Academy

3. Ontario County Sheriff’s Office

4. Industrial Load: Pactiv Corporation Manufacturing Company

5. Residential load

6. Commercial Load: Bank, Gas Station and Shopping Complex

7. Solar Array Integration

8. Suitable Wind Power Generation

The proposed microgrid has state-of-the-art Energy Management System (EMS) which

allows two-way communication as well as control between the Community Grid owner/operator

and the local distribution utility through automated, seamless integration. SCADA is used for

communication and control/communication systems are secured from

Page-7


cyber-intrusions/disruptions using Advanced Firewalls so as to protect the privacy of sensitive

data.

The HOMER Pro microgrid software by HOMER Energy is extensively used for the design

and feasibility analysis of the proposed microgrid. HOMER PRO is the global standard for

optimizing microgrid design in all sectors, from village power and island utilities to grid-

connected campuses and military bases. Originally developed at the National Renewable Energy

Laboratory, and enhanced and distributed by HOMER Energy. [1]

All the graphs in this project as well as the feasibility studies are carried out in HOMER Pro.

C. UTILITY GRID

Rochester Gas & Electric is the prime utility that serves Canandaigua. Year over year in

Canandaigua (NY), electricity rates decreased 14 %, from 19.31¢/kWh (January 2015) to

16.54¢/kWh (January 2016). [2]

D. MICROGRID CAPABILITIES

In Islanded mode, generation follows the system load and maintains system voltage as

specified by ANSI c84-1 standards.

CHP as well as the Hybrid Generator set possess black start capability. Explained in detail in

Topic 2.5.3.

Advanced and innovative technologies such as Microgrid Logic Controllers, Smart Grid

Technologies, Smart Meters, Distribution Automation are used in the proposed Microgrid.

An active network control system that optimizes demand, supply and other network

operation functions within the microgrid;

Energy efficiency is realized by using biogas in conjunction with Natural Gas. Also,

Distributed Energy Resources such as PV array and Wind mills are used to minimize new

microgrid generation requirements.

Biogas is mainly composed of Methane (CH4) gas which has catastrophic impact on the

Ozone layer. Consumption of Biogas thus minimizes environmental impacts

Peak Renewable Penetration for the proposed Microgrid was found to be as high as 58%.

Thus 58% of the loads in the Microgrid are based on Carbon-free fuels.

Page-8


2. TECHNICAL DESIGN AND CONFIGURATION

2.1 MICROGRID INFRASTRUCTURE AND OPERATIONS

The schematic layout and ETAP model of the Microgrid are depicted in figures 2 and 3

respectively.

Fig. 2. Schematic layout of the Proposed Microgrid

Page-9


Fig. 3. Microgrid Model built in ETAP

The single line diagram of the proposed microgrid can be seen in figure 4.

The proposed microgrid

uses existing distribution network. The utility connection is available through overhead system.

The microgrid has underground networks. Cables of appropriate ratings are placed in conduits to

prevent cable faults.

Page-10

Fig. 4. Single Line Diagram


2.2 LOAD CHARACTERIZATION

Loads in the proposed Microgrid can be characterized as described below.

1) RESIDENTIAL LOAD

An average household load in Canandaigua region was obtained from NREL [3]. Based on

the data obtained a normalized load profile for 250 households was used to undergo feasibility

studies. In real life, variance is observed for the load. However, keeping the average load

constant, the variations in the residential loads can be defined using Deferrable Loads. Since

New York state observes harsh winter, the load is greater for winter period.

Page-11


Fig. 5. Residential Load for a single household: Daily, Seasonal and Yearly Profile

Fig. 6. Consolidated Residential Load: Daily, Seasonal and Yearly Profile

For the consolidated residential load mentioned above, the average load per hour is

142.77kW while the peak load that the system faces is 464.08 kW with a loading factor of

around 0.31. The average consolidated residential load per day is around 3426.5kWh.

2) CRITICAL LOAD - Canandaigua School

The Canandaigua school timings are 7am to 4 pm. The average load is 94.79kW and the peak

load is 273.89kW. The load factor is around 0.35 and the school consumes around

2275kWh/day.

Fig. 7. Critical Load Canandaigua School: Daily, Seasonal and Yearly Profile

The school possesses solar installation. This can prove vital during power outage as the

critical load can be supplied by the PV arrays.

3) CRITICAL LOAD (VA MEDICAL CENTER) + COMMERCIAL LOAD

Page-12


The Canandaigua VA Medical Center is a critical facitlity. With a peak load of 250kW, the

center also possesses a CHP of 450KW capacity. Commercial load accounts for a small shopping

complex, gas station and bank. The combined load profile is demonstrated below:

Fig. 8. Critical Load (Medical Center) + Commercial Load: Daily, Seasonal and Yearly Profile

The VA Medical Center has a peak load of about 300kW and an average load of 149.38kW.

It consumes 3585kWh/day. The commercial loads on the other hand account for peak load of

100kW and an average of 40kW.

4) INDUSTRIAL LOAD

Pactiv Corporation situated at 2480 Sommers Dr, Canandaigua, NY 14424 is one of the

world’s largest manufacturers and distributors of food packaging and foodservice products.

Fig. 9. Industrial Load: Daily, Seasonal and Yearly Profile

Page-13


The average load of the plant is 206.25kW and peak load is about 476.75KW with a loading

factor of 0.43. Packaging machines and conveyor belts are the main consumers. [3]

5) DEFERRABLE LOAD

Fig. 10. Deferrable Load Yearly Profile

Since electrical load is keeps changing constantly, a deferrable load is added to the load

estimation which takes into account the variation in load. The average deferrable load is assumed

10kWh/day for the consolidated residential loads.

6) THERMAL LOAD

A thermal load is essentially used to model a building, an industrial process, equipment such

as a thermal absorption chiller, and any other system that consumes heat energy.

Since, the combined heat and power plant is used, a part of the thermal load can be satisfied

with the given "Heat Recovery Ratio" of CHP.

Fig. 11. Thermal Load: Daily, Seasonal and Yearly Profile

Page-14


With a peak thermal load of 12kW per day the thermal load accounts for a small portion of

total load.

7) CRITICAL LOAD CLASSIFICATION

The major critical loads for the system are:

1) Canandaigua VA Medical Center

2) Pactiv Corporation Emergency Supply

3) Canandaigua Academy School

4) Ontario County Sheriff’s Office

5) Bank, Gas station and Commercial Emergency power for elevators

Once the Microgrid is in an emergency condition, power is supplied to different loads as

per a pre-set Priority level which is discussed at length under the Load Shedding topic.

2.3 DISTRIBUTED ENERGY RESOURCES

The proposed microgrid possesses the following generation sources:

A. Type: COMBINED HEAT AND POWER PLANT

Rating:450kW

Fuel: Mixture of Natural Gas and Biogas

The Canandaigua Medical Center recently installed a 450KW biomass plant which serves as

a Combined Heat and Power plant for increased efficiency. Natural Gas co-fired with Biogas is

used as fuel. Excess heat is recovered thereby achieving an efficiency of 70%. Two biomass

(wood chips) fueled steam boilers utilizing computer controlled gasification technology for high

efficiency and low emissions are installed in addition to the existing central steam plant

building. The new building would additionally house a steam driven generator, automated

conveyers, 14 days’ woodchip storage, emission control equipment and supporting utilities. [4]

Maintenance:

Preventive maintenance is carried out on an annual basis to ensure reliability and durability

of the machine. It consists of the following operations: a) General inspection b) Lubrication

Page-15


service c) Cooling system service d) Fuel system service e) Servicing and testing starting

batteries f) Regular engine exercise. A detailed checklist is provided in [5].

Lubrication and Oil change are carried out once every 1000 hours.

The oil change process may take up to 10 hours.

Fig. 12. Fuel Consumption vs Output Power curve for the CHP used in the Microgrid

Fig. 13. Efficiency vs Output Power curve for the CHP used in the Microgrid

Fig. 14. Available Biomass for the CHP used in the Microgrid

Page-16


CHP plants and Diesel Gen set, with their many systems, need careful condition monitoring

to get the best out of them. Predictive and periodic maintenance techniques are essential to

obtain best service and life. An excellent way of achieving this is to use remote monitoring

techniques. Remote monitoring systems typically employ:

i. Hard-wired fieldbus systems for plant-wide applications

ii. Wireless systems such as radio frequency or GSM telemetry for remote communication

iii. Internet for global communication.

B. PHOTO VOLTAIC ARRAY

Rating: 550kW (150kW installed, 400kW proposed)

PV or solar arrays are devices that produces DC electricity in direct proportion to the global solar radiation. The power output of a PV array can be calculated by the following formula

PPV=RPV f PV

CT

CT , STC¿

If there is no effect of temperature on the PV array, the temperature coefficient of the power is zero, thus the above equation can be simplified as

PPV=Y PV f PV

CT

CT , STC

where, RPVis the rated capacity of the solar array, f PV is the de-rating factor, CTsolar radiation incident on PV array in current time step, CT , STC incident radiation under standard test conditions, α ptemperature coefficient of power, T C - PV cell temperature in current time step, T C ,STC-PV cell temperature under standard test conditions.

Generic Flat plate PV panels are installed in the proposed Microgrid. The total installed capacity is 550KW, out of which 150KW is installed on the Canandaigua Primary, Middle and Academy rooftops [6]. They have been in operation since March, 2012. Performance of PV array depends on de-rating factors like temperature, dirt and mismatched modules.

Page-17


Fig. 15. Monthly Solar Global Horizontal Irradiance Data [7]

On sunny days, each school building can capture a maximum of about 50 kWh of electricity

from the solar panel arrays which is directly consumed by the building. Remaining 400kW

solar arrays are proposed to be installed at sites as shown in Fig 1. The capital cost is

incurred by the residents.

The irradiance data for Canandaigua region as collected from National Solar Radiation

Database (National Renewable Energy Lab) and plotted in figure 7. [7]

The panel slope of 32.89º gives the maximum output. Ground reflection is assumed to be

20%.

Converter-The DC output of Solar arrays is connected to the AC bus via a Generic manufactured

converter. The efficiency of converter is 97% and it is rated up to 800KW.

Maintenance- Solar panels generally require very little maintenance since there are no moving

parts. A few times a year, the panels should be inspected for any dirt or debris that may collect.

C. WINDMILLS

Rating: 500kW

Five windmills each of rating 100kW, 400V ac are installed in the proposed Microgrid at

4962 N Rd, Canandaigua, NY 14424 (Location: 42.910365, -77.281707)

The windmills are manufactured by Norvento (nED100 model). The windmill specifications

are as follows: Rotor Diameter – 22m, Hub Height 24.5 – 29.5 – 36m, direct drive with Active

Page-18


variable pitch control and active variable speed control. It houses an inbuilt IGBT based full

power converter. It is designed and certified to IEC IIIA standards.

Fig. 16. Monthly Average Wind Speed at Canandaigua

Important features:

a. Improved Safety: Because safety is paramount, nED turbines are equipped with an advanced

control system which monitors all operating variables in real time and manages all the turbine’s

systems in order to guarantee safety and optimize energy production. This includes continuous

analysis of vibration levels; unique in medium-scale wind turbines.

b. Environmentally aware: nED turbines are oil free, negating the risk of spillages.

c. High Performance

The combination of advanced aerodynamics, variable speed and variable pitch controls and

the direct drive concept results in an improved power curve with the optimum availability in real

wind conditions.

Fig. 17. Power Curve for a 100kW Wind Turbine

Page-19


The annual average wind speed of the region is 6.57m/s as per the data collected from NASA

Surface Meteorology and Solar Energy Database. [8]

D. HYBRID GENERATOR

A 500kW rated diesel generator is installed at the Pactiv Corporation at 5250 North St,

Canandaigua, NY 14424. The generator is specifically used only during Islanded mode. The

generator uses hybrid fuel – a combination of natural gas and/or diesel. Adequate storage of

diesel is maintained. Also, black-start capability is provided by this generator.

The generator is not operated in normal operating conditions since the cost of electricity is

very high. Also, CO2 emissions and environmental impacts make it infeasible. Figures 18 and 19

show the Fuel consumption and efficiency curve for a typical 500kW generator with respect to

the power output.

Fig. 18. Fuel Consumption vs Output Power curve for the Hybrid Generator

Fig. 19. Efficiency vs Output Power curve for the Hybrid Generator

Maintenance:

Page-20


Preventive maintenance is carried out on an annual basis to ensure reliability and durability

of the machine. It consists of the following operations: a) General inspection b) Lubrication

service c) Cooling system service d) Fuel system service e) Servicing and testing starting

batteries f) Regular engine exercise. A detailed checklist is provided in [5].

Lubrication and Oil change are carried out once every 1000 hours. The oil change process

may take up to 10 hours.

CHP plants and Diesel Gen set, with their many systems, need careful condition monitoring

to get the best out of them. Predictive and periodic maintenance techniques are essential to

obtain best service and life.

An excellent way of achieving this is to use remote monitoring techniques. Remote

monitoring systems typically employ:

a. Hard-wired fieldbus systems for plant-wide applications

b. Wireless systems such as radio frequency or GSM telemetry for remote

communication

c. Internet for global communication.

E. BATTERY

A large-scale storage system CellCube FB 200-400, based on the vanadium redox flow

technology, is used in the proposed Microgrid. It is modular in nature. [9]

Page-21

Figure 20. Storage System using Vanadium Redox flow [10]


With a capacity of 800kWh and a power rating of 200 kW, battery provides large energy

reserves to cover power failures or limit peak loads.

Whether in combination with photovoltaic systems, wind power plants, diesel, gas or biogas

generators, or operated in parallel to the public grid, batteries provide optimal backup

solution to provide uninterrupted power supply.

Maintenance: Maintenance of Batteries normally includes

1. frequent monitoring,

2. Preventive maintenance every year – water level checked, individual cell output is

checked.

3. Conducting a Battery Discharge test every two years.

2.4 EFFECT OF WEATHER on DERs

Geographical location of Canandaigua makes it vulnerable to the following extreme weather

conditions:

1) Coastal Storm:

2) Cold Weather

3) Earthquake

Cold Weather – Snowfall and Icing

1. Photovoltaic system

Losses due to snowfall are dependent on the angle and technology being considered and the

effects of increased albedo in the surroundings of a PV system can increase expected yields,

particularly in the case of high tilt angle systems. Existing methods for predicting losses due to

snowfall were found to provide overly conservative estimates of snow losses. Overall the results

show that the proper assessment of snow related losses can help improve system performance

and maintenance. It is concluded that proper characterization of the snowfall effect on PV system

performance can influence better systems optimization for climates experiencing snowfall.

An approach to the impact of snow on the yield of grid connected PV systems. A report was

compiled by the Bavarian Association for the Promotion of Solar Energy and is an analysis of

snow losses on a 1MW roof mounted array in Germany at an incline of 28 degrees. The major

Page-22


findings from this report are that snow clearing can occur at panel temperatures as low as -10

degrees C, and that snow losses can range from 0.3% to 2.7% for this type of system, based on

six years of data.

2. Wind Turbines

There are three general issues important to the operation of wind turbines in cold

weather. These issues could be classified under three categories:

a. the impact of low temperatures on the physical properties of materials

b. the ice accretion on structures and surfaces

c. the presence of snow in the vicinity of a wind turbine.

Cold weather operation of wind turbines requires

these issues to be examined in the design or at least in the

phase preceding the installation of the turbines in their

working environment. Not doing so would mean

prolonged period of inactivity required for safety

purposes or because turbines inability to perform

satisfactorily.

Ice collects on both the rotating and non-rotating

surfaces. The most adverse effect of icing occurs on the

rotor itself. Its consequences on the rotor are the

following:

Interfere with the deployment of speed limiting devices

such as tip flaps or movable blade tip

Increase the static load on the rotor

Change the dynamic balance of the rotor, thereby

accelerating fatigue

Reduce the energy capture by altering the aerodynamic

profile of the rotor

Ice fragments can be propelled and represent a safety hazard for population and property in

the vicinity of wind turbines. Larger chunk can also strike the rotor and damage it.

Proposed Solutions

Page-23

Figure 21. Severe rime ice accretion on a US Windpower 56-100 turbine installed on Mt.Wquinox Vt. Note the magnitude and extent of the ice coverage. (University of Illinois at Urbana-Champaign, Dept. of Aeronautical and Astronautical Eng.)


Some solutions are already known for cold weather wind turbine operations. In fact, they

are the same as any other cold weather engineering applications. This is especially true for

materials whose low temperature behavior is well understood. For instance, the service

conditions of a steel tower will determine the type alloy used in its fabrication. This is similar for

lubricants; the application it will serve and the outside temperature will dictate the choice of a

specific lubricant.

2.5 FEASIBILITY STUDY

A. MICROGRID OPERATION

(a) Under normal conditions, the microgrid operates in Grid connected mode. Minimal

energy is imported from the grid, mainly for peak loads and load variations.

(b) Under emergency condition, the Microgrid isolates itself using the Static Switch. Loss of

Main Detection is carried out using a PLL (Phase Locked Loop). The output of the PLL

is fed to the EMS as well as IEDs and Static switches.

The proposed Microgrid is tested under two modes:

1) GRID CONNECTED MODE

In this mode, the utility is parallel to the microgrid generation. During peak hours, power is

purchased from the utility. However, there is also a provision to inject surplus power back into

the power grid with a rate of 0.105$/KWh. When running in grid connected mode, the

generation follows the load while maintaining the voltage and frequency within their tolerance

levels.

Page-24


Fig. 22. Cost Summary of Microgrid during Grid Connected Mode

Table 1. Detailed cost analysis of DERs in Grid Connected Mode

The system cost of the project for a period of 25 years is calculated which comes out to

be $3.34million. The breakdown of cost such as Operation & Maintenance, cost of

replacement if any in 25 years as well as fuel cost are shown in Table 1 pertaining to

individual DER.

Fig. 23. Monthly Average Electric Production Breakdown of Microgrid during Grid Connected Mode

Figure 23 represents the electrical cost bifurcation for the microgrid running in grid

operated mode. Figure also represents how much each Distributed Energy Resource generate,

Page-25


the consumption of energy, how much percentage of total load is supported by each DER and

the Grid sales in kWh/year.

Fig. 24. Cash flow of Microgrid during Grid Connected Mode

Figure 24 represents the amount of costs that the project will bear for a pan of 25 years.

As seen from the figure, cost is salvaged at the end of the project meaning the microgrid does

reap benefits despite high capital investment of around $1.3million.

Fig. 25. Energy Purchased and Sold in the Microgrid during Grid Connected Mode

The energy purchased from the grid in times of peak loads and the energy sold to the grid are

shown in figure 25. Annually, 953,886 kWh are purchased from the grid and 1,215,806 kWh energy

is injected in the grid. This results in a net benefit of approximately 35000$ annually.

Page-26


Fig. 26. AC Primary Load and Total Load served in the Microgrid during Grid Connected Mode

During grid connected mode, the AC load served as well as the total electrical load served

are shown in figure 26. The curves are mostly similar since no DC load is connected except the

Battery.

The distribution of energy purchased from the grid and energy sold to the grid during a year

is highlighted in figure 27.

Fig. 27. Grid sales and purchases of Microgrid during Grid Connected Mode

Page-27


Figure 28 shows the distribution of renewable penetration over a year. The unmet electrical

load is also shown. It should be noted that all load is served during the grid connected mode.

Fig. 28. Unmet Electrical Load and Renewable Penetration during Grid Connected Mode

2) ISLANDED MODE

Islanding can be defined as a condition in which a DG remains energized in a localized area

while the remainder of the electric power system loses power – a situation that can cause

damaging surges and danger to linemen who might not realize that power is still present. The

proposed microgrid is capable of sustaining itself in case of a power outage or deliberate

disconnection from utility.

Fig. 29. Cost Summary of Microgrid during Islanded Mode

Page-28


Table 2. Detailed cost analysis of DERs in Islanded Mode

The system cost of the project for a period of 25 years in islanded mode only is calculated

which comes out to be $5million. Thus, if the microgrid is operated for a year in islanded

condition, the cost would be $200,000. The breakdown of cost such as Operation and

Maintenance, cost of replacement if any in 25 years as well as fuel cost are shown in Table 1

pertaining to individual DER.

During islanded mode, the 500kW Hybrid Diesel generator is used. From Table 2, it can

be deduced that a fuel cost is considerable (around $1million) for the genset.

Figure 30 represents the Monthly Average Electric Production Breakdown for the islanded

mode. The figure also represents how much each Distributed Energy Resource generate, the

consumption of energy, how much percentage of total load is supported by each DER. The

renewable penetration in islanded mode is as high as 62%.

Fig. 30. Monthly Average Electric Production Breakdown of Microgrid during Islanded Mode

Page-29


Figure 31 represents the amount of costs that the project will bear for a pan of 25 years. As

seen from the figure, cost is salvaged at the end of the project $200,000 meaning the microgrid

does reap benefits despite running in Islanded mode. The capital investment is around

$2.3million.

Fig. 31. Cash flow of Microgrid during Islanded Mode

The Hybrid generator set uses Natural Gas and Diesel. The following figure gives a

detailed explanation of the properties of Genset in Islanded mode. The maximum and minimum

outputs of the generator are set at 150 and 500kW respectively. The fuel consumption, and the

mean electrical efficiency over a year is also shown in the figure.

Page-30


Fig. 32. Hybrid Generator Output during Islanded Mode

Wind power forms the backbone of the microgrid system during Islanded mode. Figure 33

represents the mean output as well as the capacity factor (31.56%) of the wind turbines. Wind

energy itself accounts for around 29.2% of the total load.

Fig. 33. Wind Turbine Power Output of Microgrid during Islanded Mode

During islanded mode, the AC load served as well as the total electrical load served are

shown in figure 34. The curves are mostly similar since no DC load is connected.

Page-31


Fig. 34. AC Primary Load and Total Load served in the Microgrid during Islanded Mode

Figure 35 shows the distribution of renewable penetration over a year. The unmet electrical

load is also shown. It should be noted that some load (around 40kW) is not served during the

islanded mode.

Fig. 35.

Renewable Penetration and Unmet Electrical Load of Microgrid during Islanded Mode

The national standard requires a loss of grid connection to be detected by DGs within 2

seconds, leading to an immediate trip of the DGs from the electric power system.

Page-32


So before we can connect DGs, we must evaluate the risk of violating that requirement. [11]

In case of power outage or an intentional disconnection from utility, the proposed microgrid

is capable of providing power to all the loads. However, contingencies such as Maintenance

of Windmill, inadequate irradiation or fuel unavailability (it should be noted that CHP has a

minimum of 7-day Fuel reserve) may arise.

In such cases priority levels are set and critical loads such as the VA Hospital, School and the

Sheriff’s office are given the highest priority.

PRIORITY LEVEL

Priority levels are set when the microgrid forms an intentional or unintentional island.

Level 1: Critical Facilities viz. Canandaigua VA Medical Center, Canandaigua Academy,

Ontario County Sheriff’s Office and emergency supply to Pactiv Corporation.

Level 2: Semi Critical Facilities: This includes Gas stations and banks.

Level 3: Residential Load.

Biogas is mainly composed of Methane (CH4) gas which has catastrophic impact on the

Ozone layer. Consumption of Biogas thus minimizes environmental impacts

Peak Renewable Penetration for the proposed Microgrid was found to be as high as 58% in

grid connected mode. Thus 58% of the loads in the Microgrid are based on Carbon-free fuels.

2.6 ELECTRICAL INFRASTRUCTURE

Microgrid will be connected to the utility grid at only one Point of Common Coupling

(POCC).

Microgrid will be interconnected with the grid with a transformer and a static switch.

Intelligent Electronic Devices (IED) are used for protection and bi-directional power transfer.

IEDs also have the capability of rapid communication with one another. Smart Meters are

placed at the residential and industrial loads. Smart meters have remote metering facility and

electricity consumption can be directly accessed by the user.

Lightning Arrestors are provided at the transformer for protection against lightning and

surges.

Page-33


Circuit Breakers are provided for automatic isolation of a faulty area of a network or for

intentional isolation. SF6 Circuit Breakers with rating of 1000A are used for the main

Transformer. Vacuum Circuit Breakers with 800A capacity are placed at the CHP plant; low

capacity air circuit breakers are used for DERs and fuses are used for loads.

All electrical equipment and safety devices have enough thermal capacities to sustain rated

load and even overloads.

A. CIRCUIT BREAKER

The Circuit Breakers are automatic Switches which can interrupt fault currents. The part of the

Circuit Breakers connected in one phase is called the pole. A Circuit Breaker suitable for three

phase system is called a ‘triple-pole Circuit Breaker. Each pole of the Circuit Breaker comprises

one or more interrupter or arc-extinguishing chambers. The interrupters are mounted on support

insulators. The interrupter encloses a set of fixed and moving contacts. The moving contacts can

be drawn apart by means of the operating links of the operating mechanism.

(a)

(b)

Fig. 36. (a) IEC Circuit Breaker Symbol (b) Air blast circuit breaker rated for 500 kV

Page-34


The operating mechanism of the Circuit Breaker gives the necessary energy for opening and

closing of contacts of the Circuit Breakers. The arc produced by the separation of current

carrying contacts is interrupted by a suitable medium and by adopting suitable techniques for arc

extinction. The Circuit Breaker can be classified on the basis of the arc extinction medium.

The Fault Clearing Process

During the normal operating condition, the Circuit Breaker can be opened or closed by a

station operator for the purpose of Switching and maintenance. During the abnormal or faulty

conditions, the relays sense the fault and close the trip circuit of the Circuit Breaker. Thereafter

the Circuit Breaker opens. The Circuit Breaker has two working positions, open and

closed. These correspond to open Circuit Breaker contacts and closed Circuit Breaker contacts

respectively. The operation of automatic opening and closing the contacts is achieved by

means of the operating mechanism of the Circuit Breaker. As the relay contacts close, the trip

circuit is closed and the operating mechanism of the Circuit Breaker starts the opening operation.

Fig. 37. Puffer Type SF6 Circuit Breaker Operation

(Arc is extinguished in the nozzle using compressed SF6 gas)

The contacts of the Circuit Breaker open and an arc is draw between them. The arc is

extinguished at some natural current zero of AC wave. The process of current interruption is

completed when the arc is extinguished and the current reaches final zero value. The fault is said

to be cleared.

The process of fault clearing has the following sequence:

Fault Occurs. As the fault occurs, the fault impedance being low, the currents increase and

the relay gets actuated. The moving part of the relay move because of the increase in the

Page-35


operating torque. The relay takes some time to close its contacts. Relay contacts close the trip

circuit of the Circuit Breaker closes and trip coil is energized.

The operating mechanism starts operating for the opening operation. The Circuit Breaker

contacts separate. Arc is drawn between the breaker contacts. The arc is extinguished in the

Circuit Breaker by suitable techniques. The current reaches final zero as the arc is extinguished

and does not restrict again.

B. LIGHTNING ARRESTERS

Lightning arresters are used in power and communication distribution systems to protect the

conductors from damage by a lightning strike. A standard typical lightning arrester has two

terminals namely the high-voltage terminal and a ground terminal. When the lightning hits the

distribution systems/towers, the surge introduced travels along the line to the arrestors which

then divert the current of the surge to earth.

Page-36


Fig 38. Lightning Arrestors

Lightning arrestors are placed where wires enter a structure, preventing damage to connected

electronic instruments and ensuring the safety of individuals near them. Lightning conductors are

always connected between the conductors and earth. The best part is that lightning arrestors

prevent the flow of normal power to ground, but provide a path only to high-voltage lightning

current flows, thus bypassing the connected equipment and thereby ensuring its safety. The aim

of the lightning arrestor is to prevent voltage rise in the conductors in an even of a lightning

strike. If protection fails or is absent, lightning that strikes can potentially introduce thousands of

kilovolts that may damage the distribution systems, transformers and other electronic devices.

C. SUBSTATION

Substations transform voltage from high to low, or the reverse, or perform any of several

other important functions. Substations may be owned and operated by an electrical utility, or

may be owned by a large industrial or commercial customer. Generally, substations are

unattended, relying on SCADA for remote supervision and control. A substation may

include transformers to change voltage levels between high distribution voltages and lower

distribution voltages, or at the interconnection of two different distribution voltages.

Page-37

Fig 39. Lightning arrestors installed on distribution tower


Elements of a substation:

In a large substation, circuit breakers are used to interrupt any short circuits or overload

currents. Smaller distribution stations may use recloser circuit breakers or fuses for protection of

distribution circuits. Other devices such as capacitors and voltage regulators may also be located

at substation.

Fig 40. Typical Layout of an Outdoor Substation

A. TYPES OF SUBSTATIONS

Distribution substation

A distribution substation connects two or more distribution systems. A distribution station

may have transformers to convert between two distribution voltages, voltage control/power

factor correction devices such as capacitors, reactors or static VAR compensators and equipment

such as phase shifting transformers to control power flow between two adjacent power systems.

The largest distribution substations can cover a large area (several acres/hectares) with multiple

voltage levels, many circuit breakers and a large amount of protection and control equipment

(voltage and current transformers, relays and SCADA systems).

Page-38


Distribution substation

A distribution substation transfers power from the distribution system to the distribution

system of an area. The input for a distribution substation is typically at least two distribution or

sub distribution systems. In addition to transforming voltage, distribution substations also isolate

faults in either the distribution or distribution systems. Distribution substations are typically the

points of voltage regulation.

B. DESIGN OF SUBSTATION

Selection of the location of a substation must consider many factors. Sufficient land area is

required for installation of equipment with necessary clearances for electrical safety, and for

access to maintain large apparatus such as transformers. Environmental effects of the substation

must be considered, such as drainage, noise and road traffic effects. A grounding (earthing)

system must be designed. The substation site must be reasonably central to the distribution area

to be served

Steps

The first step in planning a substation layout is the preparation of a one-line diagram, which

shows the switching and protection arrangement and the outgoing feeders or distribution

systems. In a common design, incoming lines have a disconnect switch and a circuit breaker. A

disconnect switch is used to provide isolation. A circuit breaker is used as a protection device to

interrupt fault currents automatically, and may be used to switch loads on and off, or to cut off a

line when power is flowing in the 'wrong' direction. The lines of a given voltage connect to one

or more buses. These are sets of bus-bars, usually in multiples of three. Once having established

buses for the various voltage levels, transformers may be connected between the voltage levels.

Along with this, a substation always has control circuitry needed to command the various circuit

breakers to open in case of the failure of some component.

2.7 MICROGRID CONTROL

The proposed Microgrid has a dedicated Microgrid Control Center (MGCC). It employs

EMS and SCADA for energy management, economic analysis, data logging and control

actions.

Page-39


The Microgrid operator controls the power flowing through the Microgrid.

The control options that are available in the proposed Microgrid are:

1. Automatically connecting to and disconnecting from the grid:

Microgrid isolation can occur either due to a fault in the utility grid or it could be intentional

islanding. Isolation of microgrid from the utility grid is carried out by Web-Enabled Static

Transfer Switches (eSTS) sizing 1500A. [12]

eSTS is designed to transfer power between multiple sources without interrupting critical

load

eSTS has an integrated Triple Modular

Redundancy, Power Quality Monitoring,

Remote Connectivity, Dynamic Phase

Compensation, in a convection-cooled, safe-

to-maintain design.

Transfers are very fast, less than 1/4 of an

electrical cycle, maintaining continuity for

the critical load from lapses that may be as

short as a few electrical cycles long.

The eSTS requires two or three input power sources (Preferred Source + Secondary

Source) and outputs one power source. eSTS monitors the power quality, and if a source

goes out of specification, it automatically transfers from the Preferred to the Secondary

source. [6]

2. Load shedding schemes:

During emergency conditions i.e. Fault in the utility or natural disasters such as snowfalls

or storms, IEDs will make sure that above mentioned facilities are having continuous power

[13]. Since the VA Medical Center already possesses a CHP, it will be capable of sustaining

itself. BEMS (Building Energy Managements System) [14] used in the microgrid, provides

required power initially to Canandaigua Academy School and Sheriff’s office. If the

microgrid is has excess generation, then electricity is supplied to semi critical facilities such

as Gas stations and Banks. Finally, residential areas are served.

Page-40

Figure 41. Operation of a Static Switch. CB are Circuit Breakers


3. Black start and load addition:

Biomass plant has black start capability. It employs a 120Ah DC battery for starting the

generator. Also, the storage system is capable to produce starting power. Penetration of

renewables also makes power available without any fuel. If there is load addition, new solar

panels and windmills can be constructed. Space is provided near Pactiv Corp and Canandaigua

Academy to house additional panels.

4. Performing economic dispatch and load following:

In the proposed Microgrid, economic evaluations for the best possible scenario is carried out.

The results are provided under the Feasibility study topic. The generation follows the load with

system parameters within their respective limits.

5. Demand response

Demand side Management is applicable in the proposed Microgrid. Using smart meters,

consumers can be made aware of benefits if they shift their load during peak hours.

6. Storage optimization

A 200kW, 800kWh storage system is used in the microgrid. Efficient converter control

results in storage optimization. The battery stores energy during light load conditions when

generation is greater than the demand. It functions as a DC source during peak hours or

conditions when generation is less than demand.

7. Maintaining frequency and voltage:

Frequency and Voltage of the microgrid are maintained within the tolerance limits using

MGCC and IEDs.

8. PV observability and controllability; forecasting:

The irradiance data for Canandaigua region as collected from National Solar Radiation

Database (NREL). Individual Array controls and full array controls are available at the MGCC.

Page-41


9. Coordination of protection settings:

Bi-directional Protective relays are used in the microgrid to identify faults. Overload settings

of feeders are at 120% and over-current at 150% of rated output. Standby earth fault and

differential protection are used for transformer. Protective settings of all areas are coordinated.

Extra Digital inputs and digital outputs are given to IEDs to segregate load priority levels. [16]

10. Selling energy and ancillary services:

Rochester Gas & Electric charges 16.54¢/kWh to the residential consumers. A separate smart

meter is installed to calculate energy flow from utility to microgrid and vice versa. Excess energy

is sold to the grid at 8.5¢/kWh.

11. Data logging features:

SCADA system integrated with EMS is used for data logging. Measurements are recorded

every one second and data is stored in data storage facility in MGCC.

12. Resilience:

MGCC is made up of blast proof material. It can withstand extreme conditions. Under severe

conditions, certain resources of the Microgrid may be unavailable. However, EMS and MGCC

makes sure that at least the critical loads are fed. [17]

2.8 TELECOMMUNICATIONS INFRASTRUCTURE

A) COMMUNICATION PROTOCOL

For protection and power control in Microgrid communication systems are very important.

The basic communication methods so far used in existing microgrid testbeds are: power-line

carrier, broadband over power line, leased telephone line, global system for mobile (GSM)

communication, LAN/WAN/Internet (TCP/IP), wireless radio communication, optic fiber, WiFi

802.11b, WiMAX 802.16 and ZigBee/IEEE 802.15.4 (automated metering system) [6].

The proposed microgrid system is based on the IEC 61850 protocol. It consists of a

microgrid monitoring system, a protocol converter that transforms serial data to IEC 61850 data

and distributed energy resource controllers for varied distributed energy resources nodes. IEC

Page-42


61850 has been adopted as an international communication protocol to monitor, control, and

measure power utilities.

B) CYBER SECURITY

Using Modbus again as an example, there is no authentication required for any request,

whether it be a monitor or control request. If one has access to an IP network that a Modbus

device resides on, packets can be sent to the device, and as long as they are well-formed Modbus

packets, the device will react to the packets. The DNP3 protocol, which is commonly used in

United States (US) electric power systems, has an option that some might consider a form of

authentication wherein a DNP3 device can be programmed to only respond to requests coming

from whitelisted IP addresses. However, this is not a strong form of authentication.

In the proposed Microgrid, Transport Layer Security/Secure Sockets Layer (TLS/SSL) which

is an optional cryptographic protocol is implemented on top of the TCP transport layer protocol;

it encapsulates and protects data sent using other application layer protocols. Advanced Firewalls

are also used for enhanced security. [18]

INTEROPERABILITY (IEEE 2030)

Interoperability is defined as the

capability of two or more networks, systems,

devices, applications, or components to

externally exchange and readily use information

securely & effectively. [19] Figure graphically

depicts the interoperability focus areas for the

electric power, communications, and

information technologies that constitute the

technological heart of the Smart Grid.

Figure 42. Interoperability in Microgrid

Page-43


3. ASSESSMENT OF MICRO GRID’S COMMERCIAL AND FINANCIAL

FEASIBILITY

a. 3.1 Commercial Viability:

Number of individuals: The number of people affected by this project is roughly 2500. Out of

which, 1000 are residential consumers. 350 people in VA medical center, 300 in

Canandaigua school, 500 people are in Industry and 350 people in commercial centers.

Microgrid Operator is responsible for billing the consumers based on the direct services.

However, prepaid services are offered wherein the consumers can avail the benefit of

purchasing the amount of electricity that they want.

Three main categories of customers are expected to purchase services from the micro grid.

They are namely the residential population of the location, the Pactiv Corporation

Manufacturing Company (Industry) and a group of critical centers which include

Canandaigua VA Medical Centre, Canandaigua Academy and Ontario County Sheriff’s

Office.

The other major micro grid stakeholders are the owners, government, union and employees.

All the customers and stakeholders are expected to have a positive outcome because the

micro grid is

1. Environment friendly,

2. Reduced emission due to use of biogas,

3. High renewable penetration of around 58%,

4. Minimum dependence on the grid.

5. Since CHP is used, it is able to recover the heat from the system and redirect for

steam and hot water for heating purposes.

6. The distributed generation system used requires very little maintenance and avoids

heavy costs.

7. There is a provision to inject surplus power back to the grid.

8. In the micro grid design, the critical centres are assigned certain priority levels so that

the power can be divided accordingly during faults or disturbances.

9. The technology used in the system like the Web enabled Static transfer switches

allow for power transfer without interrupting the critical load.

Page-44


The relationship between the micro grid owner and the purchaser of power can be of two

kinds:

1. One is where the customer directly pays the main utility and then depending on the

power supplied by the micro grid, the utility can pay the micro grid or

2. A Microgrid System Operator who is primarily responsible for segregating the money

paid by the customer.

During normal conditions, the micro grid operates in Grid connected mode and supplies

power to all the loads. Minimal energy is imported from the grid, mainly for peak loads and load

variations. In the islanded mode, priority levels are set and critical loads which includes the VA

Hospital and industry are given highest priority i.e. Level 1. Level 2 includes School and

Sheriff’s Office. Level 3 has semi critical facilities like gas station and banks. Level 4 is

commercial load and finally Level 5 is residential load.

The planned or executed contractual agreements with any load, critical or non-critical is

made on the basis of two parameters. The first one is on the basis of priority levels as mentioned

before. The second parameter is revenue. The contract is made on the basis of who is willing to

pay extra during an emergency situation. Microgrid Operator has a contract with the Utility

operator. The contracts are hour-based and day based.

VOLL (Value of Lost Load) is charged to interested parties who want security or

uninterrupted supply during a black out. Pactiv Corporation has a contract with the Microgrid

Operator wherein some minimum amount of power needs to be supplied to them in case of

blackout. This load is basically for the safe shutdown of the plant and functions as an emergency

supply.

One of the best ways to soliciting and registering for customers is online. This can be made

flexible with added benefits of charging the customers less if they refrain from using heavy loads

during peak hours. This works for industrial, commercial or residential customers. Microgrid

operator generally considers the residential load as a lump sum and is responsible for bidding on

their behalf and even charging them.

Since one of the distributed generation units is CHP, the heat from the system is recovered to

produce steam and hot water which could be further used in HVAC (Heating Venting and Air

Conditioning) and/or thermal absorption chiller.

Page-45


b. 3.2 Commercial Viability- Value proposition

The micro grid is environment friendly, has extremely reduced emission due to use of

biogas, a high renewable penetration of 58%, minimum dependence on the grid. Since it uses

CHP, it is able to recover the heat from the system and redirect for steam and hot water for

heating purposes. The distributed generation system used require very little maintenance and

avoid heavy costs. There is a provision to inject surplus power back to the grid. Customers not

using heavy loads during peak hours are charged less whether they are residential, commercial or

industrial. The residential customers can save money and space by installing the generation

systems like PV or small wind systems on the rooftops. In the micro grid design, the critical

centres are assigned certain priority levels so that the power can be divided accordingly during

faults or disturbances. The technology used in the system like the Web enabled Static transfer

switches allow for power transfer without interrupting the critical load.

The micro grid offers several benefits to the utility which includes concessions, decrease

in congestion, and improvement in reliability and efficiency. If utilities team up with micro grids

it can be a good revenue stream. The micro grid can provide ancillary services which the grid

can’t and a premium service charge can be applied. It is also much easier to implement

renewable through micro grids.

SWOT Analysis

The business model of the micro grid system can be elaborately explained using a SWOT

analysis.

Strengths

The micro grid is environment friendly, has extremely reduced emission due to use of biogas,

a high renewable penetration of 58%, minimum dependence on the grid. Since it uses CHP, it is

able to recover the heat from the system and redirect for steam and hot water for heating

purposes. The distributed generation system used requires very little maintenance and avoids

heavy costs. There is a provision to inject surplus power back to the grid. In the micro grid

design, the critical centres are assigned certain priority levels so that the power can be divided

accordingly during faults or disturbances. The technology used in the system like the Web

enabled Static transfer switches allow for power transfer without interrupting the critical load.

Page-46


Customers not using heavy loads during peak hours are charged less whether they are

residential, commercial or industrial. The residential customers can save money and space by

installing the generation systems like PV or small wind systems on the rooftops. In the micro

grid design, the critical centres are assigned certain priority levels so that the power can be

divided accordingly during faults or disturbances

Weaknesses

Extreme weather conditions can affect power supply and even cause utility failure. However,

there is enough generation during emergency conditions to provide uninterrupted power supply

to majority of the residents of Canandaigua. Since renewable resources are integrated in the

micro grid the peak demand may not necessarily remain same at all times, but this has been

accounted for using demand side management. Additionally, renewable system tends to be

intermittent, but a diesel generator has been added to account for such lapses.

Opportunities

One main opportunity is to extend the micro grid to the entire city of Canandaigua to ensure

uninterrupted power supply for the entire city. Another major opportunity for this system is for

the utilities to team up with micro grids which can be a good revenue stream. The micro grid can

provide ancillary services which the grid can’t and a premium service charge can be applied. It is

also much easier to implement renewable through micro grids.

Threats

The biggest threat to the micro grid is opposition from the utilities. This is due to decreasing

prices, ease of interconnection, resilience, reliability, easy to implement newer technology due to

its smaller size and mainly owing to the fact that they are able to independently meet most of the

demand.

The unique features of this micro grid include state-of-the-art Energy Management System

for two way communication, SCADA for control, communication and advanced firewalls for

cyber security, Micro grid Logic Controllers, Smart Grid technologies, Smart Meters, Distributed

Automation, Static Switches, Intelligent Electronic Devices, CellCube battery with vanadium

redox flow technology, Micro grid control center, Web Enabled Static Transfer Switches and

Building Energy Management System, High Performance IT.

Page-47


Replicability and Scalability

This project is definitely replicable due to its various benefits as explained before. The

same can be implemented in city scenarios with certain replacements in distributed generation

depending on the resources available in the city. For example, if the location doesn’t have strong

winds, instead of a PV wind hybrid, a PV micro turbine hybrid can be used.

The project is also scalable. Say for example, if a rural scenario is taken into

consideration, the size of the PV or wind say can be reduced to meet the necessary demand. And

any excess power can be sent back to the grid for a price reduction.

Need for the Project

The main purpose and need for this project is to meet the demand of the considered

location and provide a means to keep the system working even during emergency conditions.

Reliability and resilience is important for any location in order to handle any disruptive

phenomenon like weather conditions and power outages.

In this particular location, the main disruptive phenomenon is from extreme weather

conditions like rain or snowfall. This kind of a situation can affect the distribution systems of the

power system which can say, create voltage sags which can create outages. In this case, the

micro grid goes into islanding mode and supplies power based on the priority level that have

been mentioned previously. Since the PV and wind generation do not require any fuel they can

be used for their lifetime (close to 25 years). Even in the case that either of them needs a

maintenance check, the CHP system has a 7-day fuel reserve. This definitely adds value to the

system, by making it flexible, efficient, resilient and reliable.

The project adds overall value to all its customers and stakeholders. The residential and

commercial customers can save money and space by installing the generation systems like PV or

small wind systems on the rooftops. There is a provision to inject surplus power back to the grid.

Customers not using heavy loads during peak hours are charged less whether they are residential,

commercial or industrial. In the micro grid design, the critical centres are assigned certain

priority levels so that the power can be divided accordingly during faults or disturbances. The

industry can also be supplied with power during outages for a fixed charge. The micro grid offers

several benefits to the utility which includes concessions, decrease in congestion, and

Page-48


improvement in reliability and efficiency. If utilities team up with micro grids it can be a good

revenue stream. It is also much easier to implement renewable through micro grids. Other than

this the owner, government, union and employees benefit from profits made by the micro grid.

The micro grid can provide ancillary services which the grid can’t and a premium service charge

can be applied.

The added revenue streams include recovering heat from the CHP for heating purposes and

producing hot water or steam. Another stream of revenue is for the micro grid to provide

ancillary services which the grid can’t and applying a premium service charge. Also as more

biomass is used, more biogas is created which can be sold at a profit.

New York Reforming Energy Vision Objective

Since the selected location is in New York, the main policy objective to be implemented is

the New York Reforming Energy Vision Objective (NY-REV). The aim of this objective is

threefold. Firstly, it aims at 40% reduction in greenhouse gas emissions. Secondly, 50% of NY

energy should be supplied by renewables. Finally, there should be 23% decrease in energy

consumption. The proposed micro grid fulfills all the three goals. The biomass fueled CHP

systems allow for minimized emissions. Since the system allows for a maximum of 58% of

renewable penetration, the second goal is fulfilled. With an effective Energy Management

System and technology like smart meters and demand side management, the energy flow is

balanced and energy consumption can be reduced. Any surplus power can be sent back to the

utility.

c. 3.3 Commercial Viability- Creating and Delivering Value

The technologies being used here have been indicated in the map. The PV which is being

deployed at the area marked in the map and Canandaigua Academy. The CHP is at the hospital

and finally the wind systems are installed area given in the map.

PV: The advantages of PV include clean energy, decreasing operation and maintenance costs,

lack of moving parts, no noise, easy to install on rooftops or ground. Its disadvantages include

intermittency issues, unpredictability, need for inverters and storage systems, large area

requirement, low efficiency levels.

Page-49


Wind: Its benefits involve sustainable and clean source, cost effective, zero emissions, can be

used in remote areas, availability in various sizes for different applications. Its challenges are

high cost, large area for installation, noise and aesthetic pollution, damage to local wildlife.

CHP: Its pros include increased efficiency, increased reliability, independence from the grid,

acts as an energy multiplier. Its cons are high cost, suitable mostly when both hot water and

electricity are needed.

Distributed Automation: It is essential in reducing line loss, improving power quality, energy

cost reduction and optimal energy use and improved reliability. But they may not be able to

withstand a severe environment. Weak distribution systems disrupt it from working effectively.

Intelligent Electronic Devices: These devices are helpful in increasing power availability and

improving power quality in Power Distribution Networks. They can help optimize the controller

directly and record the load curves for future planning. They also help prevent overload

situations. But its initial cost is high and it requires highly qualified professionals for operation.

Automatic Metering: Its advantages include improved security and energy management, less

expenditure, improved billing etc. Its disadvantages are loss of privacy, reduced reliability, and

increased security risks.

Logic Controllers: They can be re-programmed and can create complex logic without complex

wiring. It I also flexible, space efficient and comes at a low cost. But they are easily affected by

environment, high temperatures and harsh vibrations.

The already available assets being included in this project are the 450KW biomass plant at

the Canandaigua Medical Plant. The PV systems installed at the Canandaigua Academy.

Design: The design of this system is planned keeping in mind the needs of all the loads in

consideration including the peak loads and generation units of the necessary ratings have been

Page-50


taken. The ratings have been mentioned earlier. This has been down not only with peaks but also

by keeping the disruptions and islanding in mind.

Technology: The IEDs manage the system by controlling the operation off circuit breakers,

transformers and capacitor banks. Distributed Automation performs real time adjustment and

managing of loads, generation, and distribution without the need of an operator. The automatic

metering systems helps in accurate readings and improved billing and the logic controller can

help control the system with the ability to be re-programmed. All of these systems allow for a

good control and monitoring system of the entire power system which helps in balancing the

power flow through the system and ensuring there is no power loss and in immediately detecting

any faults or disruptions.

Contracts: The contracts mainly ensure that during islanded mode, the power is balanced by

setting up priority levels for all the loads which has been discussed before. This is mainly to keep

important systems up and running like the critical loads. In the grid connected mode it is

necessary to maintain contracts on which loads the micro grids will serve and the utility rates for

the power generated. Furthermore, contracts can be set up for municipalisation of the micro grids

in order to improve reliability and reduce overall costs.

The main permissions needed for this project include land acquisition permission for the

solar and wind farms. And the land/building owner’s consents for installing any of generating

unit. And in case the micro grid needs to through the utility regarding the services to be provided

and the charges applied. These generally apply to any micro grid. Since most micro grids involve

PV or wind they need to acquire land depending on the demand. Even if other units are micro

turbines or CHP are being installed then there is the question of where they will be installed and

whether permission will be given. And since most micro grids need to work in coordination with

the main grid they need to work out the necessary details.

About 50% of the micro grid is already developed. The biomass plant being used for CHP

was installed in 2009. And the PV system in Canandaigua Academy have been in operation since

March 2012. The newer systems proposed is expected to be implemented in 1.5 years. Also

Page-51


another proposal is to use an independent system operator that can coordinate, monitor, and

control the utility and the micro grid.

The micro grid benefits passed to the community have been explained earlier. The additional

costs include capital cost, maintenance cost, electrical inspection costs and system operator cost.

The utility can improve the value for the customers by ensuring that the any ancillary service that

the utility itself cannot provide can be taken over by the micro grid. And an independent system

operator can be set up to coordinate between utility and the micro grid.

PV: PV systems have been used in multiple micro grids. For example, in Kythnos Island a

10KW of PV systems have been used in a micro grid to power a village. PV systems are mainly

used in location where there is warm weather for most of the year. The important things to keep

in mind is to maintain a very good storage system due to its intermittency. Usually PV is paired

with another generation system to account for outages.

Wind: After PV, Wind is the most popular renewable generation system. The heat can be

recovered and used for heating systems. For example, Bornholm Island in Denmark uses wind

turbines to power its micro grid. The key lessons here are similar to the PV system. Since even

wind is a renewable source, it requires to be paired with another generation system or an efficient

energy storage.

CHP: This generation system is known for its high efficiency. For example, New York

University uses CHP to power its campus. But the most important aspect to be taken care of is

that it is usually suitable in areas where there is a need for steam or hot water.

Diesel Generator: They are the most efficient and cost effective generating systems

available and their reliability has given them an edge over other generators. For example, along

with wind turbines the Bornholm Island micro grid used diesel generators. With respect to diesel

generators it is important to realize that if they are looked after on a regular basis they can be

long lasting.

Battery: The vanadium redox battery being used is a comparatively new technology but has

many advantages including almost unlimited energy capacity, safe and non-inflammable and its

ability to be left completely discharged for long periods with no ill effects. The micro grid being

Page-52


set up jointly by California Energy Commission and the US Navy will have vanadium redox

batteries. The lesson here is that these are useful only for stationary applications.

SCADA: This system is used for control, communication as well as for cyber security. It

provides centralized monitoring and improved efficiency along with full use of communication

availability. But its installation and maintenance cost need to be considered before including it in

the plan.

EMS: This system uses an advanced energy system which is the first of its kind. This is used

for data logging, monitoring and control.

Technical: Under normal conditions micro grid operates in Grid connected mode. Minimal

energy is taken from the grid for variations and peak loads. Under emergency condition, micro

grid isolates itself from the grid using static switch and operates in islanded mode.

Financial: The customers can pay the grid directly and the micro grid can be paid based on

the supply. Or an ISO can be set up. The customers can be pay directly to the ISO which divides

the cost to the utility and micro grid based on the supply.

Transactional: For the customers two ways of transactions are possible. Firstly, they can have

an end of the month payment plan or if they prefer otherwise, they can use a prepaid system.

Schools and industries are charged less because they are heavy loads and require constant

supply.

Decision Making: The entire system is monitored using SCADA and EMS system. This

system can effectively and quickly detect any system faults and disruptions and take immediate

action. The power system also has a system operator to take important decisions.

The customers can pay the grid directly and the micro grid can be paid based on the supply.

Or an ISO can be set up. The customers can be pay directly to the ISO which divides the cost

to the utility and micro grid based on the supply. Also if any of the customers are able to give

back surplus power to the grid, they are charged less. Smart meters are used meter the

purchasers’ use.

There is a high probability of business/commercialization and replication for this type of a

project. For example, if we were to find a location with similar resources it would be possible

to replicate this project as PV and wind are the most abundantly available renewable

resources. Also since this project has a high level of renewable usage, it is possible to replace

Page-53


the system with resources already available such as a micro turbine running on natural gas.

The main barrier for the market entry of micro grids is the opposition from the utilities. But

of late, even utilities have begun to realize that teaming up with micro grid can actually be a

good revenue stream say for example providing extra services through the micro grid and

charge a fixed price.

Yes, the proposer demonstrates the steps to overcome barriers. The contracts that have been

proposed for the system allows the micro grid is subjected to buy a minimum amount of

electricity from the grid. Micro grid allows for provision of black start capability will help

the utility in case the utility fails. It also has an effective load shedding scheme which ensures

that the critical centres are always in operation. Demand side management being

implemented provides a huge benefit to the customers. Most importantly the Micro Grid

Control Centers are made of blast proof material and are extremely resilient to extreme

weather conditions.

Yes, the market has been identified and characterized. The main customers have been

identified depending on which strategies and contracts have been proposed. There is a clear

picture of what should take place in case of an outage, what to do in case of islanded mode,

how VOLL is charged, how Black start capability is exploited, etc.

d. 3.4 Financial Viability

The charges will include basic service charge which is fixed, a sales tax and tariff surcharge

which varies depending on the location. Apart from this additional charges like capital cost,

maintenance cost, inspection cost and system operator cost which are all variable depending

on the location. Also there is the cost of congestion, because if congestion occurs during peak

loads, it can cause an increase in Marginal price at a few locations.

The main incentives of the system include steam, hot water, decrease in emission, high use of

renewable sources and constant power supply. These don’t require any timing to be taken

into consideration.

The capital and operating costs are separate for building each generation, distribution and

distribution system. These costs are variable depending on the required demand.

This system is made profitable by the resources used including the high performance IT

systems, control and communication systems involving EMS, SCADA etc. which along with

Page-54


the provision to send surplus power back to grid ensure minimum power loss. Also CHP

systems used recover costs by recovering the heat and using it to produce steam or hot water.

Both PV and wind avoid further costs due to negligible maintenance. The battery storage

system also is a onetime cost as it a long lifetime. It will take 1.5 years to reach a break-even

point. Also, the considered loads are peak loads which is generally not the case but this helps

us get more savings.

There are three main ways of financing a micro grid. One is Power Purchasing Agreements

(PPA), where the customer agrees to buy all or a part of the electricity generated by a micro

grid for a specific period. Here the customer pays only if power is actually generated. Second

way is leasing which is third-party-ownership system, where a leasing company owns the

micro grid and leases it to the customer over a period of few years. For this term customer is

responsible for operating and maintaining the micro grid and for consuming the electricity it

generates. In exchange a series of recurring lease payments is made to the leasing company.

This system can be modified based on customer needs. Another way is Energy Savings

Performance Contracts (ESPC). This requires no upfront capital from the customer. The

contractor provides the initial capital which can be recovered if there is cost savings. So it is

cash flow neutral. So, the amount of monthly energy savings is supposed to be minimum

equal to the monthly payment needed to finance the improvements.

e. 3.5 Legal Viability

There are mainly three types of ownerships that can be implemented. Direct ownership,

where the owner controls all aspects like financing, building, operation and maintenance. It has

the highest return and the largest risk. Joint ownership, where one party finances and the other

agrees to develop and operate the micro grid. There is a slight risk here. Third party ownership,

where everything including finance, developing, operation and ownership are outsourced. There

is significant risk but also good potential returns. The team members include owner, government,

union and employees. Also there can be representatives for the residential and industrial sections

to supervise the development and come up with possible solutions for various scenarios.

The project owner can be a company set up by the residents or a semi private company which

has the residents has stakeholders and it manages the project. System Operator is a part of this

company and is responsible for operating, maintaining and if necessary developing the system.

Page-55


There is generally a different operator for the distribution system and a different one for the

distribution system. Even the utility can set up its own micro grids.

Yes, the project owner in this case owns the site too where micro grid systems need to be

installed. If the situation was otherwise, the site owner can be paid an appropriate amount for

acquiring the land.

To maintain the privacy of all customers and securing the data, the control and

communication systems will be enabled with advanced firewalls. The system will also be

enabled with remote monitoring to promote efficiency, early detection and decrease in

disruption.

On a technical note the micro grid can face problems with voltage and frequency, islanding

and protection which can be prevented using micro grid controllers, effective communication

systems and efficient protection systems. Apart from this which is currently being worked

upon is the lack of an established standard for micro grids. Recently the IEEE 1547.4 was

adopted for the same. Another challenge discussed previously is the lack of support and

consent from utility which is slowly changing as the utilities have recognized the importance

of micro grids.

4. INFORMATION FOR BENEFIT COST ANALYSIS

a. 4.1 Facility and Customer Description

1) RESIDENTIAL LOAD

Rate class- Residential

Economic Sector- Private residential.

Priority Level- Non critical load.

Type of rate payer- There are approximately 250 apartment buildings in the designated

microgrid region. Though most of them would be single family apartments (single rate

payers), some of them could be a multi-family structure as well. Since there is Canandaigua

Academy in the vicinity, it is not uncommon for apartments to be rented out separately as

lower and upper levels.

Average Annual Electricity demand- 142.77kWh

Peak electricity demand- 464.08kWh

Page-56


Percentage of load demand that can be covered by the micro grid in case of an outage- It falls

under the least essential load category. The loads have been divided into priority levels and

the residential load is at the last rung. Only If there is extra generation available after feeding

the critical loads, the residential load will be supplied. However, Canandaigua receives harsh

winters, it is not possible to expect the residence to live without heat and in complete

darkness in an event of an outage during the winter. For this case a critical load for worst

case scenario has been calculated as 100 kwh

The number of hours per day, on average, the facility would require electricity from the

microgrid- As explained above, the electricity supplied is designed to vary with seasons. For

outages during winter months’ electricity will have to be supplied all day long to power the

heaters and other minimal essentials. So the critical residential load for these months would

be higher than those during spring and summer. The residential load is at its minimum from

eight in the morning to six in the evening. Except heat no electricity will be supplied during

these hours except on Sunday’s. For the remaining hours 100kwh or electricity will be

supplied with the residence requested to use bare minimum.

2) INDUSTRIAL LOAD

Rate class- Pactiv Corporation is one of the world’s largest manufacturers and distributors of

food packaging and foodservice products. It falls under the rate category of large industrial

load.

Economic Sector- Large scale manufacturing.

Priority Level- Critical Load Level 1 (EMERGENCY POWER)

Type of rate payer- The Pactiv Corporation is taken as a single load and thus is a single rate

payer.



Percentage of load demand that can be covered by the micro grid in case of an outage-

150kW is calculated critical load which will be met at all times irrespective of the grid

connection mode.


microgrid: Being a manufacturing industry, Pactiv Corp plants runs a shift with peak hours

Page-57


from 10am to 6pm. During non-peak hours, salient operations and preparations are carried

out. During an outage, the industry would work at full output from 10am till 6 pm.

3) COMMERCIAL LOAD

A. Canandaigua VA Medical Centre

Rate class- Large Commercial Load.

Economic Sector- Non-profit social welfare organization.

Priority Level- Critical load level 1.

Type of rate payer- Single rate payer.


Peak electricity demand-300kWh

Percentage of load demand that can be covered by the micro grid in case of an outage- The

Canandaigua Medical Center recently installed a 450KW biomass plant which serves as a

Combined Heat and Power plant for increased efficiency. Natural Gas co-fired with Biogas is

used as fuel. Being a level 1 critical load, the onsite CHP is more than capable of satisfying

the demand of the medical center.


microgrid- The medical center will receive electricity throughout the day. It will have the

ability to operate at full scale without the need to cut down on usage. In case a scenario arises

where due to lengthy outages, a choice needs to be made, the medical center will be the first

priority above all other loads. Also the critical load for the medical center has been calculated

as 100kwh.

B. Canandaigua Academy School

Rate class- Large Commercial Load.

Economic Sector- Non-profit educational organization.

Priority Level- Critical Load Level 2


Average Annual Electricity demand-94.79kWh


Page-58



academy has an onsite solar array installed capacity of 150kW. 400kW of solar capacity is

further proposed. The place of installation will be the academic campus itself. The academy

functions from eight in the morning to five in the evening. Only the library remains open

after hours. Also the school remains shut on Saturdays and Sundays which makes it easy to

satisfy other loads such as residential loads.


microgrid- Being designated as a critical load, it will be supplied with electricity throughout

its working hours. However, the library may be asked to remain shut after operating hours to

conserve energy and lower the loads in an event of a complete grid outage.

C. Ontario County Sheriff’s office

Rate class- Small commercial load

Economic Sector- Non-profit social development and protection organization

Priority Level- Critical load level 2


Average Annual Electricity and Peak electricity demand- The load demand has been

calculated and taken into consideration along with residential loads. However, the sheriff’s

office has a higher priority level and will take priority over all residential loads.


sheriff’s office will have emergency lightings, which will sustain some amount of electric

load that is essential to the office such as lightings and computers.


microgrid- The sheriff’s office is a critical structure that needs to be operational always.

Though designated as level 2 priorities it will always have some amount of electricity to keep

it operational at all times.

b. 4.2 Characterization of Distributed Energy Resources

I. SOLAR PANEL ARRAY

Energy/fuel source- Natural renewable sources of energy (Sun)

Nameplate capacity- 150kW installed and 400 kW proposed to be installed.

Page-59


Estimated average annual production (MWh) under normal operating conditions has been

presented earlier.

Average daily production (MWh/day) in the event of a major power outage has been

presented earlier.

For fuel-based DER, fuel consumption per MWh generated (MMBtu/MWh) has been

presented earlier.

The maximum amount of time it would be able to operate in islanded mode without

replenishing its fuel supply and the amount of fuel consumed during this period – The solar

panel runs on energy from the sun. Fuel is of no problem. It does not need to be refueled. It

will produce energy as long as the sun shines.

The percentage of nameplate capacity at which each backup generator is likely to operate

during an extended power outage-The percentage output depends on the intensity of the sun

and weather phenomena’s.

Average daily electricity production (MWh/day) for each generator in the event of a major

power outage which has been presented earlier.

Population served by this facility- It is primarily set up to power Canandaigua’s Academy,

but in an event of an outage the power would be diverted to loads in a manner of priority

level. The remaining 400kW, will serve the residential load and commercial load primarily.

Describe how a power outage would impact this facility’s ability to provide services. If

possible, estimate a percentage loss in the facility’s ability to serve its population during a

power outage, relative to normal operations (e.g., 20% service loss during a power outage),

both when the facility is operating on backup power and when backup power is not available-

The PV’s on an average generate only around 100kWh of energy despite the installed

capacity being of 400kW. As explained above, the PV’s are primarily for set up to power

Canandaigua’s Academy, but in an event of an outage the power would be diverted to loads

in a manner of priority level. When excess power is generated, it will either be stored in the

batteries or sold back to the grid. However, in an outage if the power is redirected say to the

industry or to the medical facility, the service loss during this period would then be the other

remaining facilities like the Academy and residential.

Apart from installation cost, the only other cost incurred would be cost of maintenance. The

maintenance would ideally be carried out every 3 to 6 months and would involve basic

Page-60


maintenance like cleaning the surface of the PV cells and conducting a systems check. The

cost has been presented through the earlier graphs.

II. WINDMILL

Energy/fuel source- Natural renewable sources of energy (Sun)

Nameplate capacity- 5 windmills of 100 kW capacity each. Total capacity 500kW

Estimated average annual production (MWh) under normal operating conditions is shown

earlier.

Average daily production (MWh/day) in the event of a major power outage is shown earlier.

For fuel-based DER, fuel consumption per MWh generated (MMBtu/MWh is shown earlier.


replenishing its fuel supply and the amount of fuel consumed during this period- The

windmills runs on energy from the sun. Fuel is of no problem. It does not need to be refueled.

It will produce energy as long as the sun shines and the wind blows.


during an extended power outage is shown earlier.


power outage, and the associated amount of fuel (MMBtu/day) required to generate that

electricity- percentage output depends on the intensity of the winds and other weather

phenomena’s

Estimate the population served by this facility- The power generated from the windmills is

turning out to be cheaper than the grid. So the windmills along with the PV’s and CHP (VA

medical facility requires only around 200kWh-250kWh from the 450 KWh installed

capacity) have the ability to completely satisfy the load. Similar to PV’s when excess power

is generated, it will either be stored in the batteries or sold back to the grid. However, in an

outage if the power is redirected say to the industry or to the medical facility, the service loss

during this period would then be the other remaining facilities like the Academy and

residential.

Describe how a power outage would impact each facility’s ability to provide services. If



Page-61



The installed capacity of the windmills is 500Kw, however on an average only 169KW’s of

energy is produced. In grid connected mode as explained wind power is cheaper than that of

the grid so it takes preference above the grid. It gets stored in batteries as well as sold back to

the grid. But during periods of extended outage say if the CHP and the PV array satisfy the

loads for the industry and the medical facility, the wind power will be used for residential

load. A combination of any of the DER’s can be used to satisfy various loads at different

times.

Apart from installation cost, the only other cost incurred would be cost of maintenance. The

maintenance would ideally be carried out every 3 to 6 months and would involve basic

maintenance like cleaning the blades of the windmill and conducting a systems check. The

costs have been discussed earlier through the graphs.

III. Hybrid Diesel Fuel Generator

Energy/fuel source- Diesel and natural gas

Nameplate capacity- 500kW


earlier.


For fuel-based DER, fuel consumption per MWh generated (MMBtu/MWh) is shown earlier.


replenishing its fuel supply and the amount of fuel consumed during this period- The facility

will have a fuel storage capacity of 10,000 gallons of diesel storage and 538,188 cubic feet of

natural gas storage. (Refer Appendix A, Table 3 and 4) This would give it 15-20 days of

supply at full load.

The installed gen set is of 500KW capacity. The amount of fuel consumed would vary

according to the load as can be seen from the figure.


during an extended power outage- The generator is a prime type generator which can operate

for extended periods of time at varying loads. This would be ideal for extended periods of

outage. We are installing a prime type generator instead of a standby generator as standby

Page-62


generators have a rated period of continuous operation and operating them over lengthy

periods of time results in frequent breakdowns. If the gen set is powering only the industry, it

can operate at 50% of the capacity but if it were to power other loads as well in addition to its

industrial load then it would operate at 100% rated capacity.



electricity. It can operate at 100% rated capacity as Prime Generators have larger cooling

systems compared to continuous type or standby type. The amount of diesel consumed would

vary from 11gallons to 35.7 gallons depending upon the load satisfied and the natural gas

consumed would vary between 2276 cubic feet to 6407 cubic feet depending on the load.

Estimate the population served by each facility- The gen set is primarily as a backup for the

industry.





The gen set will only be used during an event of an outage as it is costlier than the grid. It is

an emergency backup for the manufacturing facility but for extended outage it has enough

fuel for up to 20 days. Depending upon the fuel availability for the CHP, the generator may

even power the medical facility in case of an emergency.

Kindly refer Maintenance under 2.3 and the aforementioned graphs.

IV. COMBINED HEAT AND POWER PLANT

Energy/fuel source- Natural Gas co-fired with Biogas

Nameplate capacity-450Kw


earlier.


For fuel-based DER, fuel consumption per MWh generated (MMBtu/MWh) is shown earlier.


replenishing its fuel supply and the amount of fuel consumed during this period- For 15 to 20

Page-63


days. The natural gas storage capacity is similar to that installed at the industry. In addition,

the hospital already has a 7-day storage capacity for biogas, which would be upgraded to 15

days.


during an extended power outage- If the CHP is powering only the medical facility it can

operate at 50% of the capacity but if it were to power other loads as well in addition to this

load then it would operate at 100% rated capacity.



electricity- Commonly accepted heating values for natural gas and diesel fuel are 1020 Btu

per cubic foot of natural gas and 138,000 Btu per gallon of diesel fuel. It has an efficiency of

up to 70%.

Estimate the population served by each facility- The CHP will only serve the medical

facility. It will not serve any other load during an event of outage as the CHP’s fuel source

needs to be conserved to ride through extended periods of outages.





The facility will continue to serve the medical facility. No loss of service.

Kindly refer Maintenance under 2.3 and the earlier graphs.

CellCube FB 200-400 Battery-

Based on the vanadium redox flow technology.

Capacity of 800kWh and a power rating of 200 kW.

Load Served- The storage power will be used to power the residential loads so they are not

completely left without power. Residential loads which is a mix of single housing units and

separately rented upper and lower apartments belongs to the least priority load. In the event

of a lengthy outage the probability of residential loads been left in complete darkness goes up

as the power gets diverted to other higher priority loads.

Page-64


Having a battery set increases the black-start capability of the grid. (Explained in detail in

2.5.3)

c. 4.3 Capacity Impacts and Ancillary Services

The impact of the expected provision of peak load support on generating capacity

requirements (MW/year)

The onsite installed DER’s ensure the fulfilment of the peak load. In fact, the installed

combination not only full fill the load but even have the capability to sell excess energy back to

the grid there by earning revenue for the microgrid. Due to the location, the solar panels installed

are not as efficient as expected, but on the flip side the location ensures steady operation of the

wind turbines. The CHP power plant is primarily reserved for the medical centre. In the event of

a blackout the CHP will power the medical centre first. Only if excess generation is available

will other facilities be powered using the CHP. The same can be said for the hybrid diesel gen set

installed at the industry. Since both the industry and the medical centre are level 1 critical load, it

becomes imperative to ensure their loads are satisfied.

Capacity (MW/year) of demand response that would be available by each facility the microgrid

would serve- For the demand response aspect certain non-critical loads can be asked to alter their

load characteristics but the same cannot be said about critical loads. The non-critical residential

load can be made to change its load characteristics that are the time and period of its peak load

and average load. Using smart meters, the residence can be made aware of the spot prices of the

electricity at that particular instant there by instilling the habit of using house hold equipment’s

at a different time and there by altering the systems peak load. The proposed Microgrid has state-

of-the-art Energy Management System (EMS) which allows two-way communication as well as

control between the Community Grid owner/operator and the local distribution utility through

automated, seamless integration. The same can be applied for the Canandaigua Academy as well.

Since it has only specific operating hours, the period of operation and the electricity consumed

can be altered up to a certain extent.

Page-65


Associated impact (deferral or avoidance) on distribution and distribution capacity requirements

(MW/year)- Same distribution network of the grid is used for the microgrid so no changes in

capacity requirements are necessary

Ancillary services to the local utility (e.g., frequency or real power support, voltage or reactive

power support, black start or system restoration support) – In Islanded mode, generation follows

the system load and maintains system voltage as specified by ANSI c84-1 standards. CHP which

can run on natural gas and bio gas, possesses black start capability (Explained in detail in Topic

2.5.3). Advanced and innovative technologies such as Microgrid Logic Controllers, Smart Grid

Technologies, Smart Meters, Distribution Automation are used in the proposed Microgrid. An

active network control system that optimizes demand, supply and other network operation

functions within the microgrid; Energy. Also, Distributed Energy Resources such as PV array

and Wind mills are used to minimize new microgrid generation requirements. A diesel gen set is

used within the industrial complex which has the capability to use diesel as well as natural gas as

a fuel. Peak Renewable Penetration for the proposed Microgrid is as high as 58%.

Estimates of the projected annual energy savings from development of a new combined heat and

power (CHP) system relative to the current heating system and current type of fuel being used by

such system- A new CHP is not going to be installed. The VA medical centre already possesses a

450kW CHP which uses a mixture of natural gas and biogas for fuel. Excess heat is recovered

thereby achieving an efficiency of 70%. Two biomass (wood chips) fuelled steam boilers

utilizing computer controlled gasification technology for high efficiency and low emissions are

installed in addition to the existing central steam plant. The facility also houses a steam driven

generator, automated conveyers, 7 days’ woodchip storage, emission control equipment and

supporting utilities.

Environmental regulations have been discussed much in detail later.

d. 4.4 Project costs

These points have been discussed under the Feasibility section. (Refer Topic 2.4)

e. 4.5 Cost to maintain Services during power outage


Page-66


f. 4.6 Services Supported by the microgrid


5. ENVIRONMENTAL CONSIDERATIONS

5.1 ENVIRONMENTAL REGULATIONS AND STANDARDS

The Obama administration created one of the most significant milestones in the US CHP

industry’s history when it announced a presidential goal to increase the resource 50 percent by

2020. The Department of Energy’s CHP Technical Assistance Partnerships (CHP TAPs) is

focused on achieving the 40 GW goal.

The policy is expected to:

i. Cut energy bills by $10 billion a year compared to current energy use

ii. -Save the equivalent of 1 percent of all energy use in the U.S.

iii. -Reduce carbon dioxide (C02) emissions by 150 million tons annually

iv. -Infuse $40-$80 billion in new capital investment in manufacturing

Emissions regulations also are likely to encourage more CHP in North America. ICF

International estimates that 3.5 GW of CHP could be added to meet certain emissions targets. A

study by the ACEEE found that potential for CHP to save 68 million MWh of energy by 2030.

[19]

The availability of reliable, resilient, and affordable electric service is critical to the welfare of

citizenry and is essential to New York’s economy. To ensure continuing economic growth and

prosperity for New York, Governor Andrew M. Cuomo laid out an ambitious energy agenda for

the State in 2015, with the Public Service Commission (PSC) playing an important role in

crafting the significant regulatory changes needed to make the Governor’s agenda a reality.

Under Governor Cuomo’s “Reforming the Energy Vision” (REV) strategy, New York is

actively spurring clean energy innovation, bringing new investments into the State and

improving consumer choice and affordability. In its role, the PSC is aligning markets and the

regulatory landscape with the overarching state policy objectives of giving all customers new

opportunities for energy savings, local power generation, and enhanced reliability to provide

safe, clean, and affordable electric service. The REV initiative will lead to regulatory changes

Page-67


that promote more efficient use of energy, deeper penetration of renewable energy resources

such as wind and solar, wider deployment of “distributed” energy resources, such as micro grids,

roof-top solar and other on-site power supplies, and storage. It will also promote markets to

achieve greater use of advanced energy management products to enhance demand elasticity and

efficiencies. These changes, in turn, will empower customers by allowing them more choice in

how they manage and consume electric energy.

Some of the goals and guidelines set by REV strategy are

40% reduction in greenhouse gases (GHG) from 1990 level.

50% of electricity generation from renewable sources.

23% decrease in energy consumption by buildings from 2012 level. [23]

Outlined below is the four-step approach AEE Institute’s paper, A Performance-based

Approach to Allowance Allocation for Clean Power Plan Compliance, explains that allocation to

affected units on the basis of historical generation — the proposed approach under EPA’s

proposed mass-based Federal Plan and Model Trading Rule — is the least effective of the many

options available to states. For states that decide to adopt it, the historical generation approach to

allocation will limit compliance options, hamper competition, and introduce market uncertainty,

which is likely to drive compliance costs higher for electricity customers relative to other

allocation systems. This paper describes one alternative, performance-based allocation, which

would award allowances on a technology-neutral basis according to the emission reductions

achieved in the prior year. By allowing all eligible emission reduction measures to participate on

the basis of cost and value, a performance-based approach would create an open and competitive

marketplace, lowering compliance costs for affected units and ratepayers alike. The steps in brief

are outlined below:

1. Clean Energy Incentive Program (CEIP) Allocation: During the first step period, states should

set aside an allocation sufficient to support early action under the CEIP.

2. Competitive Emission Reduction Allocation: Under this, the primary allocation method,

allowances would be provided to all eligible zero- and low-emitting technologies (including

EGUs operating below their relevant subcategorized emission performance rate) in direct

Page-68


proportion to their emission reduction benefits. The allowance quantity would be based on the

number of megawatt hours (MWh) each resource generated or saved in the previous year.

3. Prevent Leakage

All states are required to avoid the risk of emissions leakage from existing EGUs, which

are regulated under the CPP, to new EGUs, which are not. Adopting the CPP’s New Source

Complement (NSC) is the most seamless way to reliably and predictably meet this requirement.

Any states that do not adopt the NSC should set aside a certain number of allowances for low-

and zero emitting technologies representing the minimum number necessary to prevent leakage

to new emitting units. (EPA has identified allocation to these resources as a mechanism to

address leakage.) These allowances would be distributed via the Competitive Emission

Reduction Allocation (Step 2) and would constitute a “floor” and not a “cap” on the total

allowances available to these measures. States, including those that adopt the NSC, could also

increase this “floor” to achieve other policy goals, such as accelerated deployment of cost-

effective advanced energy measures.

4. Distribute Remaining Allowances:

Allowances not yet awarded after the first three steps would be sold at auction, or allocated

through some other approach. An auction would help eliminate the downsides of upfront

allocation to affected EGUs on the basis of historical generation, and instead create a more

efficient market for emission reductions. State officials would determine, likely through

legislation, the most effective use of the revenue from the allowance auction, which could serve

numerous policy goals. For states in which auction is not an option, there are several alternatives,

including allocation to load serving entities (LSEs), or an updating output-based allocation.

5.2 ENVIRONMENTAL IMPACTS

Different types of Environmental Impacts owing to new Microgrid projects are:

i. Land Use: The construction and operation of distribution systems can lead to significant

land use changes in the distribution rights-of-way and on the grounds of associated

Page-69


facilities. Agriculture, transportation etc. can be affected by the placement of distribution

systems and towers near airports, roads, and waterways.

ii. Forest Impacts: distribution system construction and maintenance can lead to the

conversion of forest ecosystem into bare-land or land covered by completely different

vegetation communities. Fragmentation, pesticide use, and invasive plant species within

the right-of-way can also affect surrounding forest areas.

iii. Wetland and Riparian Impacts: distribution system construction and maintenance can

ecosystem destroy or disturb plant and animal communities, and introduce invasive

species. Soil compaction and soil erosion in wetlands and riparian areas can alter

hydrology and nutrient flows essential to ecosystem functions.

iv. Hydrologic Changes: Distribution system construction can alter hydrology, remove plant

cover, and altering existing drainages or creating new ones. Altered hydrology can affect

aquatic, wetland, and riparian habitats and species, and can affect soil moisture and

surface water availability in other kinds of ecosystems.

v. Soil Erosion: distribution system construction can lead to soil erosion by removing

vegetation cover, compacting soils, and cutting into banks. Erosion can reduce soil

fertility and lead to siltation, which affects water quality and productivity in aquatic and

wetland ecosystems.

vi. Biodiversity Impacts: The construction and operation of distribution systems can affect

habitat conversion and fragmentation, changes in hydrology, soil compaction and

erosion, pesticide use, introduced species, and hunting and harvesting enabled by rights-

of-way and construction roads. Species in small, rare, sensitive, and otherwise critical

habitats may be especially affected.

vii. Wildlife Impacts: The wildlife impacts of distribution system construction and operation

include bird electrocutions and collisions, changes in predator-prey. It increases in

hunting and fishing enabled by rights-of-way and construction/maintenance roads.

viii. Toxic and Water Pollution: Toxic pollution from distribution systems can result from

pesticide use in rights-of-way, and from the leakage of PCBs from equipment that

contains them. Water pollution can result from inadequate wastewater treatment for

construction camps, workshops, etc.

Page-70


ix. Electromagnetic Interference (EMI): Corona and induced electromagnetic fields from the

operation of high voltage distribution systems can produce electromagnetic interference

(EMI), or electrical noise. It affects the functioning of electronic and telecommunications

equipment. “Jitter” in television screens and computer monitors can result from EMI.

x. Audible Noise: Corona from the operation of high voltage distribution systems can make

audible noises, - “hissing,” in the vicinity of the right-of-way. Transformers also produce

noises often described as “humming,” which are frequently audible outside substation

borders.

Best practices for assessing and reducing environmental impacts in distribution projects

For reducing the environmental impacts of distribution system construction and operation

inevitably begin with the environmental assessment (EA) process and the preparation of written

environmental impact studies. Alternative Routings: Alternative routings must be proposed for

distribution rights-of-way, as well as alternative locations for substations and other distribution

facilities. Specific Design Features: Proposed line designs used for environmental assessment

purposes must include, for each section of each alternative route, the specific information

essential to determining potential environmental impacts, including right-of-way width.

Technical Alternatives: Possible use of DC distribution, and the possible use of underground

cables to substitute for overhead lines. Comparative Assessment: Environmental assessment

stresses the comparative assessment of the proposed alternative routings, line designs, and

technical alternatives. Social Impacts: Social, cultural, and economic impacts on affected

populations are included within the meaning and basic intent of the environmental assessment

process. Expert Assessment in the Field: Empirical investigations of conditions and potential

impacts in the field must be undertaken by appropriate experts.

Public Input: The environmental assessment process must actively solicit public input,

including that of affected communities and non-governmental organizations (NGOs). Mitigation

Plans: Specific mitigation measures to reduce specific impacts identified in the environmental

assessment must be concretely described in a mitigation plan. Monitoring of environmental

impacts, and of the ongoing implementation of mitigation plans, must be an integral part of the

construction and ongoing operation of the distribution facilities.

Page-71


6. SOCIAL CONSIDERATIONS

Resettlement: The need to clear land for distribution can result in the removal of people living

in these locations, and their resettlement in new locations. It can be socially and economically

disruptive to the people affected, and ecologically damaging to the area in which they are

resettled.

Indigenous Peoples: Distribution systems and associated facilities, and roads built for

construction and access, can affect indigenous communities in a variety of ways, including

removal and resettlement from ancestral homes, destruction or damage of important cultural

sites. The opening of previously remote areas to commerce and interactions with outsiders.

Economic Disruption: The construction and operation of distribution systems and associated

facilities can affect local economies by disrupting agriculture, by producing or eliminating local

jobs in construction or maintenance. Affects property values for reasons such as aesthetic

changes, perceptions of hazard, and road access.

Cultural Sites: distribution system construction can affect cultural sites such as areas of

archaeological, historical, or religious significance. Burial sites and buried artifacts may be

disturbed, especially when trenches are required for underground cables.

Aesthetic Impacts: distribution systems and towers are unattractive to many people, especially

when located near their homes or near scenic sites such as parks and river crossings.

7. SAFETY CONSIDERATIONS

Distribution systems present a risk of electrocution to the public, by direct contact with high

voltage equipment and lines, and also by induced voltages. Humans and farm animals can also

risk electrocution or nuisance shock when inadequate grounding at substations energizes metal

objects, such as stock tanks, outside substation grounds. Other safety threats include the collapse

of distribution towers during storms. The following mentioned Health Considerations are also a

part of Safety Considerations.

8. HEALTH CONSIDERATIONS

The human body has permeability that of air, however the electromagnetic values within the

body varies with frequency. Blood and lymph are ion rich fluids which make up for the electric

Page-72


charge of the human body. These body currents are produced by induction. Charges on the

power line attract or repel the charges within the body. The charges on the power line change

from positive to negative rapidly in each second resulting in the surface body charge of the

human body to vary as well. The currents induced in the body are concentrated on the body

surface. The electric current induced varies from person to person and so does their effects. For

human beings to experience a shock limit for undisturbed field is 15 kV/m, R.M.S. When

designing a distribution system, this limit should not be crossed. According to research and

publications put out by the World Health Organization(WHO), distribution systems can cause

the following health problems:

Short term Health Problems include Insomnia, Muscle pain, Headaches, Skin rash,

Dizziness

Long term Health Problems are:

1. DNA damage: Scientific research has proved that every cell in your body may have its own

EMF. Strong, external EMFs like those from power lines can scramble and interfere with our

body’s natural EMF. Affecting sleep cycles, immune system & even DNA

2. Risk of Cancer: Recent research has confirmed the link between EMF and cancer. High

Voltage power lines are the most obvious and dangerous culprits.

3. Risk of Leukemia: Researchers found that children living within 650 feet of power lines had

a 70% greater risk for leukemia than children living 2,000 feet away or more. (As per British

Medical Journal, June, 2005).

4. Risk of Neurodegenerative disease: Occupational exposure to low frequency EMF leads to

neurodegenerative disorders (As per Epidemiology, 2003 Jul; 14(4):413-9).

5. Risk of Miscarriage: Extreme exposure to electric fields even leads to miscarriages (As per

Epidemiology, 2002 Jan; 13(1):9-20)

9. ETHICAL CONCERNS

15kV/m R.M.S is the limit above which the human body experiences a shock. Care has to be

taken that while designing the distribution systems this threshold value should not be crossed.

Due to various health effects of distribution systems, the nearby residence should be made

completely aware of the possible dangers. Though distribution systems generally pass through

isolated areas, their introduction into any locality sees a drop in the real estate price. Farmers and

Page-73


land owners have to be adequately compensated for the right of way that would be utilizes by the

distribution towers.

10. SUSTAINABILITY IN POWER SYSTEM

Sustainable energy is the form of energy obtained from non-exhaustible resources or green

resources. Green Energy is energy that can be extracted, generated, and/or consumed without any

significant negative impact to the environment. Green power is a subset of renewable energy and

represents those renewable energy resources and technologies that provide the highest

environmental benefit. Most of these technologies are economically competitive due to dip in

prices. Renewable energy technologies are essential contributors to sustainable energy as they

generally contribute to world energy security, reducing dependence on fossil fuel resources and

providing opportunities for mitigating greenhouse gases.

11. CONCLUSION

The main aim of the project is to make a self-sustaining Microgrid. Various Loads and

DERs are illustrated and explained. Feasibility analysis gives us a broader view of how the

system operates under grid connected operation and under islanded mode. Cost Analysis of both

the modes state that the microgrid is capable of handling both the cases. Almost all the load

(99.99%) is met during islanded condition. The unmet load is basically due to the scheduled

maintenance of the Diesel generator which has been set for a frequency of 1 year.

Issues that a microgrid can face owing to legal, financial and environmental matters have

been identified and potential solutions have been proposed. While designing a microgrid, apart

from the technical details, factors such as economic, environmental, ethical, health, safety and

social also needs to be considered. At the end of the day, all of these parameters need to come

together while setting up any microgrid. And as responsible Engineers, it is our duty to keep all

these in mind to arrive at the best design.

REFERENCES

[1] The HOMER Pro® microgrid software by HOMER Energy [Online] Available at:

http://www.e-wisdom.com/states/new-york/canandaigua/ [Accessed: 31-Mar-2016]

Page-74

https://en.wikipedia.org/wiki/Fossil_fuel

https://en.wikipedia.org/wiki/Energy_security


[2] Energy in Canandaigua, NY [Online] Available at: http://www.e-wisdom.com/states/new-

york/canandaigua/ [Accessed: 31-Mar-2016]

[3] Buildings Research, National Renewable Energy Laboratory, [Online] Available at:

http://www.nrel.gov/buildings/ [Accessed: 31-Mar-2016]

[4] Combined Heating and Power Renewable Energy Project [Online] Available at:

http://www.canandaigua.va.gov/features/Renewable-Energy-Project.asp [Accessed: 02-Apr-

2016]

[5] Power topic #7004, “Maintenance is one key towards generator set reliability”, [Online]

Available at: http://www.sbsbattery.com/UserFiles/File/Power%20Qual/PT-7004-

Maintenance.pdf [Accessed: 02-Apr-2016]

[6] Solar Power Updates, Canandaigua City School District [Online] Available at:

http://www.canandaiguaschools.org/district.cfm?subpage=27618 [Accessed: 02-Apr-2016]

[7] National Solar Radiation Database, National Renewable Energy Laboratory [Online]

Available at: http://rredc.nrel.gov/solar/old_data/nsrdb/ [Accessed: 02-Apr-2016]

[8] Surface Meteorology and Solar Energy Database, NASA, [Online] Available

at: https://eosweb.larc.nasa.gov/sse/ [Accessed: 02-Apr-2016]

[9] CellCube energy storage system for continuous power supply, [Online] Available at:

http://energy.gildemeister.com/en/store/cellcube-fb-200 [Accessed: 02-Apr-2016]

[10] Vanadium Redox Battery Operation, America Pink, [Online] Available at:

http://america.pink/vanadium-redox-battery_4637103.html [Accessed: 03-Apr-2016]

[11] Ben Kroposki, Charlie Vartanian, “Microgrids Standards and Protocols”, [Online] Available

at: http://e2rg.com/microgrid/standards_breakout2.pdf [Accessed: 02-Apr-2016]

[12] Static Transfer Switches, LayerZero Power Systems Inc., [Online] Available at:

http://www.layerzero.com/Products/Static-Transfer-Switches/index.html [Accessed: 02-Apr-

2016]

[13] H. Akagi, Y. Ito and Z. Yang, “DC microgrid based distribution power generation system”,

IEEE, Power Electronics and Motion Control Conference, vol3, pp1740-1745, Aug 2004.

[14] P. Piagi and R. Lasseter, “Autonomous control of microgrids”, IEEE, Power Engineering

Society General Meeting, pp 1-8, June 2006.

Page-75

http://e2rg.com/microgrid/standards_breakout2.pdf

http://america.pink/vanadium-redox-battery_4637103.html

http://energy.gildemeister.com/en/store/cellcube-fb-200

https://eosweb.larc.nasa.gov/sse/

http://rredc.nrel.gov/solar/old_data/nsrdb/

http://www.canandaigua.va.gov/features/Renewable_Energy_Project.asp

http://www.e-wisdom.com/states/new-york/canandaigua/

http://www.e-wisdom.com/states/new-york/canandaigua/


[15] F. Katiraei and M. R. Iravani. “Power managements strategies for a microgrid with mulitiple

distributed generation units”, IEEE, Transaction on power system, vol 21, pp 1821-1831,

Nov 2006.

[16] Ritwik Majumder, Manjula Dewadasa, Arindam Ghosh, Gerard Ledwich, Firuz Zare,

“Control and protection of a microgrid connected to utility through back-to-back converters”,

Electric Power Systems Research, Volume 81, Issue 7, July 2011, Pages 1424-1435, ISSN

0378-7796

[17] Michael Angelo Pedrasa, Ted Spooner, "A Survey of Techniques Used to Control Microgrid

Generation and Storage during Island Operation." AUPEC2006.

[18] Cynthia K. Veitch, Jordan M. Henry, Bryan T. Richardson, Derek H. Hart, “Microgrid Cyber

Security Reference Architecture”, Sandia Report, July 2013

[19] “Microgrids and ‘Micro-municipalization,’” Microgrids and "Micro-municipalization". [Online]. Available at http://blog.rmi.org/blog_2013_07_23_microgrids_and_municipalization. [Accessed: 07-May-2016]

[20] [Online]. Available at: http://www.dieselserviceandsupply.com/diesel_generators.aspx?filter=manufactureres. [Accessed: 07-May-2016].

[21] “Approximate Diesel Generator Fuel Consumption Chart,” Approximate Diesel Generator

Fuel Consumption Chart. [Online]. Available at:

http://www.dieselserviceandsupply.com/diesel_fuel_consumption.aspx. [Accessed: 07-May-

2016].

[22] “Energy Consumption,” American Gas Association. [Online]. Available at:

https://www.aga.org/annual-statistics/energy-consumption. [Accessed: 07-May-2016].

[23] “Department of Public Service,” New York State. [Online]. Available at:

http://www3.dps.ny.gov/. [Accessed: 07-May-2016].

[24] Diesel Generators, Supply and Fuel [Online]. Available at:

http://www.dieselserviceandsupply.com/diesel_generators.aspx?filter=manufactureres.

[Accessed: 07-May-2016]

[25] Microgrids and B. Lab, "Bornholm island," 2016. [Online]. Available: https://building-

microgrid.lbl.gov/bornholm-island. Accessed: May 9, 2016

Page-76

https://building-


[26] "Vanadium redox battery," in Wikipedia, Wikimedia Foundation, 2016. [Online]. Available:

https://en.wikipedia.org/wiki/Vanadium_redox_battery. Accessed: May 9, 2016

[27] Assignment, "Buses," 1994. [Online]. Available:

http://www.mathworks.com/help/simulink/ug/buses.html?refresh=true. Accessed: May 9, 2016

[28] "ECEN2060 MATLAB/Simulink materials,". [Online]. Available:

http://ecee.colorado.edu/~ecen2060/matlab.html. Accessed: May 9, 2016.

[29] Edvard, "8 major advantages of distribution automation | EEP," in High Voltage, EEP -

Electrical Engineering Portal, 2015. [Online]. Available: http://electrical-engineering-

portal.com/8-major-advantages-of-distribution-automation. Accessed: May 9, 2016.

[30] I. V. Banu and M. Istrate, "Figure 7. The Simulink model of the 20kV utility grid," 2008.

[Online]. Available: https://www.researchgate.net/figure/267095055_fig4_Figure-7-The-

Simulink-model-of-the-20kV-Utility-Grid-with-position-of-the-short-circuit. Accessed: May 9,

2016

[31] T. MathWorks, "Asynchronous machine," 1994. [Online]. Available:

http://www.mathworks.com/help/physmod/sps/powersys/ref/asynchronousmachine.html.

Accessed: May 9, 2016.

APPENDIX A

Table 3: Diesel consumption chart [21]

Page-77


Table 4: Natural gas Consumption chart [24]

Page-78

Documents

Design of Micro Grid