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Village Water Ozonization Solutions Power Source

Engineering Senior Project Final Design Report

Composed by:

Ian Leslie Computer Engineering Concentration Messiah College

Gerald Mwangi Computer Engineering Concentration Messiah College

Advised by:

Dr. Timothy Whitmoyer Engineering Department Messiah College

Ariela Vader Biology Department Messiah College

In Cooperation with:

Village Water Ozonization Water Group The Collaboratory

Solutions Team

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Table of Contents

Contents

Acknowledgements........................................................................... 3

Introduction ......................................................................................... 4

Design Process ................................................................................. 15

Implementation ............................................................................... 24

Project Management ..................................................................... 32

Budget .................................................................................................. 34

Conclusions ........................................................................................ 35

Future Work ...................................................................................... 38

Bibliography ...................................................................................... 39

Appendix Contents ......................................................................... 40

VWOS Solar Installation and Maintenance Manual ........ 41

Solar Power Source Specifications ......................................... 59

Pictures ................................................................................................ 62

Cost Analysis ..................................................................................... 72

Gantt Charts ....................................................................................... 73

Testing Results & Raw Data ....................................................... 75

Budget .................................................................................................. 79

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Acknowledgements We would like to thank the following people for their valuable advice and continued

support throughout our project:

Dr. Timothy Whitmoyer

Prof. Ariela Vader

Water Purification Team

Steve Frank

Adelani Osunsakin, Evan Liem

Prof. Carl Erikson

Dr. Donald Pratt

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Introduction 1.1 History

In Laguna, Honduras, there is an existing need for clean water which exceeds the

community resources. As a result of lack of clean water, most people in these

communities are subject to water related diseases where the prevalence of waterborne

diseases among community members has been on a steady increase. Previous tests

carried out on the water indicate high levels of bacteria and contamination in the water.

As a developing country where most people are not making enough money to buy

bottled water, which is considerably expensive, most of the local people are bent to use

the unclean water for their daily needs.

The other problem exists in the fact that Laguna does not have reliable electricity to

power the Ozone Water Purification System. As a result, our fundamental focus was to

design a solar based power source for the purifier that would supply enough electrical

power to run the system all year round at maximum performance.

1.2 Abstract

An ongoing project, the Ozone Water Purification system design aims at disinfecting

water using ozone. In order to provide clean drinking water to roughly one thousand

(1000) people in Laguna, our team had the task of designing a power source capable of

giving a power output of over 300 watts at maximum performance. A fundamental goal

focused on designing a Photovoltaic (PV) system to provide enough power to run the

purification system for a potential 10 hours a day at 3 gallons per minute.

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The project team members are Gerald Mwangi and Ian Leslie, computer engineering

seniors at Messiah College. The project faculty advisors are Dr. Timothy Whitmoyer, and

Prof. Ariela Vader. This project was executed in conjunction with the Water Purification

group in The Collaboratory for Strategic Partnerships and Applied research.

1.3 Project Description

Initial tests of the prototype Ozone Water Purifier were run on a standard 12 volt lead-

acid battery connected to a 400 watt inverter. The outcome was a functional system

with a 12 to 15 minute lifetime. A significant reason to the low performance in system

run time greatly attributed to lack of a deep cycling battery to run the tests. Building on

the principles of the initial design, our team designed and assembled a PV based system

to power a full scale Ozone Water Purification unit generating comprehensive data

guaranteeing maximum performance of the system. (See test results)

The Ozone Water Purifier consists of two key components that use electrical power: the

ozone generators and the water pump. These components had a total current rating of

2.5 amps drawing a maximum of 300 watts. (See Appendix for further Design

Calculations)

A key aspect of our system is the grid and generator capabilities with limited tweaking of

the existing system. Our team was not able to test grid and generator capabilities but

underlying technology and technical research proves that these extra power sources

would be easy to integrate with our present system.

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A fundamental achievement is that our solar system meets the water purification

specifications exceeding them by 7% in terms of power supply needed, maintenance

and installation costs.

1.4 Purpose

Continuing the work of the previous senior project team, we built a cost effective PV

system that not only met the expected standards but exceed them allowing room for

system expansion beyond the 1000 people radius. In meeting our financial constraints

(see cost analysis), we designed a PV system that is rugged, easy to operate and

maintain thus proving more favorable for our installation environment. With the need

to be environmentally sensitive, our system exploits natural resources with no negative

repercussions to the surrounding environment.

A key motivation for our involvement in this project was the recognition and the

familiarity we both, being international students from Africa, have had with the lack of

clean drinking water both directly and indirectly. Therefore having experienced similar

problems, we felt that it was in part our obligation as engineers, to be sensitive to the

need at hand. Being a service oriented project, we realized that it was a unique calling

and divine opportunity to serve the less fortunate with a timely completion of the

project.

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1.5 Objectives

To ensure the completion of the project, we enacted several major objectives that

would serve as the project roadmap:

To a PV system that will provide 375 watts for 9 hours a day all year round at

maximum performance as dictated by our system specifications.

To have a fully functional and ready to implement power source by May 2nd,

2008.

To Complete The VWOS installation and maintenance manual

Completed a detailed financial analysis showing break even points and overall

cost of running the system.

To design a simple, effective power source for less than $3000 hundred dollars

including installation cost.

To complete the initial design and integration phase by mid April, 2008.

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1.6 Literature review

There are several units that have been put together and are out in the industry that

combine the use of solar energy and basic water purification systems for remote areas.

At the moment, we have not been able to get any information on Ozone water

purification systems that are based on solar systems but the following systems that use

other purifications styles have a close correlation with our system.

A specific system that was of great interest to as is designed and manufactured by Aqua

Sun Water Purification Company. With a potential to produce 3 gallons per minute,

most of their systems are solar powered and do not require grid electrical energy to run

them. They are often dual powered systems integrating solar energy and battery power.

Below is a link to some of their solar based designs.

http://www.aqua-sun-intl.com/products/swp-c3.htm

The battery system in this design requires 6 sun-hours to be fully charged while running

the system at maximum potential. Despite the lack of an immediate price quote, their

system has great similarities to our system.

Another system that we looked at is designed and manufactured by Wycomar UV and

Purification systems. Below is a diagram of their portable solar based water purification

system.

http://www.aquatechtrade.com/marketplace/mypage/products_detail.asp?mypageid=

785&productid=728

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From this research, it is evident that solar energy has become a contributing factor in

the development of water purification systems for rural areas. The longevity of solar

powered systems offsets the initial cost of the system making it the most appropriate

source of energy for these kinds of systems. The underlying concept of using solar

energy to power basic water purification systems seems be taking more ground thus

giving purification companies a wider variety of options when it comes to powering their

systems.

Another key state of the art technology combining solar energy and water purification is

designed for large scale production by GE Global Research in München, Germany. Their

system can produce over 2.000 liters of clean water from any well that is available. A

tool for sizing the needed PV generator, for identifying the appropriate pump including

controls and water storage is currently designed by GEGR-E.

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Solar Cube, a collaborative effort by Spectra WaterMakers, San Rafael, Calif., and

Switzerland-based Trunz has taken the step further by providing a multifunctional PV-

Wind based water purifier that can be used to support domestic power needs. Designed

to provide relief to communities affected by natural disasters, the system can supply

1,000 gallons of drinkable water from a saltwater source and up to 3,500 gallons of

clean drinking water per day from a polluted freshwater source, including rivers, creeks,

and wells. Moreover, the Solar Cube can generate enough energy for disaster officials to

power refrigeration for emergency medical supplies, keep a laptop online, or charge a

cell phone. Depending on the solar and wind conditions, excess electricity to run

emergency equipment is approximately 1,200W.

Portable and self-contained, the Solar Cube operates by storing energy from the sun via

photovoltaic solar panels — or from wind by means of a wind generator — into a bank

of built-in 24V batteries. The batteries send power to the water delivery pump and the

pre-filtration system to remove large matter. Next, the water is run through the reverse

osmosis desalinization module, which purifies the water by eliminating bacteria, viruses,

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salt, and chemicals. If the water is contaminated with oil, an oil-water separator or an oil

pre-filter can be added to the unit as needed.

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1.7 Alternatives

There are several other energy alternatives that we looked at before we concluded with

going solar. The other key sources we looked at are as listed:

Wind energy - The reality of using wind energy was limited by efficiency and lack

of a site survey. At the same time, wind energy is not as reliable as solar energy.

While we can expect about three hours of solar energy on a minimum, we can go

for a few days without enough wind energy to run the system. We therefore

concluded that despite wind energy being a great idea, solar energy would be

more reliable, cheaper and effective.

Hydro power - The site has good running water that could be potential for hydro

power. Unfortunately, the size of the project would increase by nearly four times

and would require a detailed ground implementation team while solar energy

can be implemented by a smaller team with little solar expertise. Another reason

we did not explore this option so much was the potential cost of building and

installing a hydro power station to run the system. Water level reduction would

also mean reduction in electricity produced as a result minimal performance.

Integration with the grid system and a generator would even prove to be more

challenging.

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Our system thus qualifies on the following advantages:

Portability - we are in a potential to design a small portable and easy to assemble

power source. The size of the system will thus not be occupying a lot of space

thus making it easier for the installation team to work with it. Despite the weight

of the batteries, our analysis proved that the system will be portable at a

minimal cost. With our prototype, enthusiastic entrepreneurs could further

make portable Solar-Ozone based purification systems for small scale and

individual production at minimal costs.

Efficiency - Solar energy is readily available thus a great natural resource to tap

into. Our system will get great performance from tapping into this alternative

energy source and it will be easy to supplement it with generator energy on days

when we do not have enough sunshine.

Cost - In comparison with the other sources of energy mentioned above, solar

energy is the cheapest to work with in respect to longevity and maintenance

costs. While we might pay a lot of money up front to put together the solar

system, there will be no more significant charges to maintain the system. In

comparison to hydro thermal for instance, it would need regular oiling of

turbines and clean up of the system that would demand well trained personnel

and finances to do system upkeep.

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Longevity - Solar energy can be harnessed from this kind of a system for a period

of close to 25 years with minimal maintenance requirements thus solidifying our

argument that solar energy is the best alternative for this design.

1.8 Funding

Our key sources for funding are:

1. The Collaboratory in coordination with the Ozone Water purification group.

2. Messiah College Department of Engineering.

3. Fund raising from friends and family through The Collaboratory.

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Design Process The rating of our final design is 375 Watts. This was achieved by using three 125 Watt

solar arrays. Our design also incorporates a 400 Ah battery bank. As part of our design

the system voltage is constant throughout at 12 Volts.

Our initial design last semester was for a 300 Watt system. This power rating was based

on the prototype purification system designed by last year’s senior project. The

electrical components on that system included two ozone generators and an ultraviolet

light filter, combining for a total peak power rating of around 190 Watts. As the

prototype underwent changes this year, our designs went through a few revisions as

well. Ultimately, the VWOS team decided to go for a system that had a peak load of 257

Watts. Reflecting this, our final system is rated at 375 Watts. This takes into account

losses due to voltage drops across wiring and components. It also accounts for the fact

that while the solar panels are each rated at 125 Watts, this rating assumes optimal

operating conditions, which won’t always be the case.

There are several technical issues that were focused on in our design:

Functionality: With Laguna having no grid power, we built a multi-source power

supply. Our PV system is capable of simple integration to a generator power

source.

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Due to the somewhat expensive transportation cost of the heavy solar batteries,

the VWOS team decided not to purchase batteries in the US but to do it in

country. A secondary but expensive option was to design our system to run on

car batteries, an option that would have rendered an efficiency loss of

approximately 25% in terms of maximum power production and sustenance,

thus rendering a challenge to find deep cycling solar batteries to test our system

with.

Continued redesign of the Purification System demanded power recalculations

on our end. We as a result had to redesign our system three times to incorporate

the Water Purification System changes.

Timely delivery from a supplier failed due to departmental miscommunication.

This in effect demanded significant accommodating changes to our time

schedule.

Solar power can be challenging and costly. In designing the solar interface, we

built a cheap, efficient and long lasting system.

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2.1 Feasibility

There are several key constraints that we had to accommodate to facilitate the

completion of this project:

Time: With a one year time frame, we built our system meeting the time limits

and were able to effectively test our system to determine overall performance.

Having completed our research and primary cost analysis as the first phase of

our design, we were able to assemble, test and document our system by April

22nd 2008.

Financial analysis (see appendix) of the entire system puts it at reasonable price

facilitating completing the project in a timely fashion.

The very fact that solar energy will only have a significant upfront cost and lower

maintenance costs makes a better choice of energy to implement.

Site Survey: A key procedure in the installation of solar energy is calculating tilt

angles and site survey for the prospective location. Lack of site accessibility a

fundamental challenge of calculating over estimates on system performance to

compensate potential loss in system performance due to the installation errors.

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2.2 Other Challenges

Limited familiarity with the production of solar energy set a limit into our understanding

of some of the design challenges. A key challenge was narrowing down on parts needed

due to different manufacturer’s ratings and overhead costs to different components.

The functionality of each of the components based upon the manufacturers ratings

were often times slightly above or below our expectations demanding slight changes in

our system specifications. (See appendix for final design components)

A secondary challenge posed was in designing a system that would have an aesthetic

appeal, user friendliness, ruggedness, with state of the art technology; a system that

meets the standards described in our objectives and at the same time, beats other

systems in the market by scaling down manufacturing, assembly and maintenance costs

in respect to our budget.

A third and fundamentally crucial challenge was to design a system with projected site

data. Since we could not do an actual onsite survey, we for one had to project our test

results in hopes that would fall within a reasonable margin of error. Another key aspect

was the fact that we could not calculate actual tilt angles or measure sunlight intensity

at the actual site and thus had to rely on projected data in regards to overall system

performance.

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2.3 Analysis/Experimental Work

Power sources are seen as the heart of electrical components and their failure renders

the entire electrical system a failure. To ensure we have a stable power source, we

subjected it to a multiplicity of tests.

Heat tests - most power sources due to drawing large currents tend to

overheat. We therefore examine how much heat our power source will be

generating and with that information determine how we can compensate

that for a long lasting performance.

Cost Analysis between using a generator all year round in comparison to a

generator and solar power alternatively (See appendix).

Battery Performance Testing - we will hopefully be able to subject the

battery storage to a potential load for a maximum time that we hope to run

the system daily in hopes to determine the actual amount of time the battery

storage can run the system with no recharge.

Ruggedness testing - we will test the basic system setup to determine how

rugged the system is and in writing the maintenance manual can make it

clear how the system should be handled and what level of care is needed

with it.

System stability tests - Most electronic devices behave differently when

subjected to different voltages outside their specifications. A major problem

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is when you have device failure or shut down due to high voltage, low

voltage and thermal loading. A system can be quite indeterminate if these

factors have not been taken to account.

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2.4 Specifications

Target System: System Load : 257 W (±10 %) Load time/day : 2.2 kWh

Solar Panel Specifications: 12 V Output Voltage Max. Power : (depends on configuration) Max. Voltage : 19 V (± 10%) Max. Current : 7.5 A (± 5%) Open Circ. Voltage. : 21.7 V (± 5%) Short Circ. Current : 7.1 A (± 5%) Max. System Voltage : 750 VDC Weight : 30 lbs (± 10%)

Battery Specifications: Sealed Lead AGM Voltage : 12 V Amp-Hrs : 100 A-H (± 10%) Dimensions: Length : 25” (± 10%) Width : 15” (± 10%) Height : 15” (± 10%) Weight : 66 lbs (± 10%)

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Inverter Specifications:

Cont. Power rating : 600 W Output Waveform : Pure Sine Wave Peak Power rating : 1000 W, 10 minutes (± 10%) DC Input Voltage : 10.0 V – 15.5 V AC Output Volt. (RMS) : 115 V (± 10%) AC Output Frequency : 60 Hz (± 0.1%) Peak Efficiency : 90 % (± 5%) Low Voltage Disc (LVD) : 10.5 V (± 0.5%) Low Voltage Reconnect : 11.6 V (± 0.5%) LVD Warning : 10.8 V (± 0.5%) High Voltage Disc : 15.5 V (± 0.5%) High Voltage Reconnect : 14.5 V (± 0.5%)

Charge Controller Specifications:

Type : PWM Output Current Rating : 25 A (± 10%) System Voltage : 12 V Max Open Circ. Volt. : 30 V Charge Volt. Adjust. : 13 V – 16 V

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2.4 Final Design

Our final design incorporates three solar panels wired in parallel, going through a

combiner box with a 25A DC fuse, through the charge controller, and into the battery

bank, through an inverter, to which the load is connected.

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Implementation

The system was assembled at Professor Erikson’s farm.

3.1 Components and Assembly

1. Solar Array: This is the heart of the solar power system and also happens to be

most expensive part of our project. The solar array consists of solar cells that

chemically convert solar energy to electrical energy. In assembly, we wired the

panels in parallel using compatible adapters to increase amperage while holding

the voltage at 12 volts constant. Our system has three 12 volt Kyocera modules

wired in parallel. The solar panels output variable DC current. This raw output

cannot run directly into the battery pack hence, the need for a charge controller.

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The PV modules that we decided on are Kyocera KC125G panels. They are 125

Watt panels rated at 12 Volts. The 125 Watt rating is called peak wattage, which

is the output power under very specific conditions of solar irradiance and

temperature. The power output will be below that under normal operating

conditions. The conversion efficiency, which is the percentage of power

converted (from absorbed light to electrical energy) and collected, is about

15%...which is good by industry standards. It has a life span of 25 years plus. The

solar cells in the module are encapsulated between a tempered glass cover and a

back sheet to provide good protection from severe environmental conditions.

The entire laminate is contained in an anodized aluminium frame to provide

structural strength and ease of installation.

2. Charge Controller: The charge controller protects the battery from overcharging

and also protects the solar panels from damaging effects of reverse currents. It

regulates the rate of electricity going into the battery and keeps it constant.

Most charge controllers will use a relay with a blocking diode to prevent reverse

currents at night to the PV system.

The charge controller prevents battery overcharge by reducing the flow of

energy to the battery system upon the batteries achieving a set voltage. When

the charge drops below the nominal value due to lower sunlight intensity or as a

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result of electric load increases, the charge controller then allows more energy

into the battery system. (Voltage Regulation)

In our particular design, we implemented a PWM (pulse with modulation) charge

controller. A two stage regulator was more preferable in that it first holds the

voltage to a safe maximum for the battery bank to achieve their full charge

capacity. Upon full charge, the charge controller drops the voltage lower to

sustain a "finish" or "trickle" charge.

Our design also took into account overload situations. Overloads happen when

more current flows than the system can handle. This can cause overheating and

can even be a fire hazard. Built-in overload protection can be useful, but most

systems require additional protection in the form of fuses or circuit breakers and

our system took great use of breakers and fuses. A circuit with a wire size for

which the safe carrying capacity is less than the overload limit of the controller,

requires circuit protection with a fuse or breaker of a suitably lower amp rating.

We thus decide to buy a charge controller that has inbuilt temperature

compensation which works by checking the battery temperature and comparing

that with the controller set points. Set points, the voltages at which the

controller changes the charge rate, and their determination depends on the

anticipated patterns of usage, the type of battery, and to some extent, the

experience and philosophy of the system designer or operator. In our design,

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when the controller senses a low battery temperature, it will raise the set points,

otherwise when the battery is cold, it will reduce the charge too soon.

3. Battery Pack: The batteries are one of the most important components in the

power system. As mentioned earlier, the batteries used in this project are test

batteries that will not be used on site. The batteries store the charge generated

by the solar panels so that it is available in a stable, usable form. We most likely

be using two 12 Volt batteries. We will be using sealed lead AGM batteries as

they are simple and maintenance free. The batteries we eventually decided on

are Trojan CB27 sealed lead AGM (Absorbent Glass Mat) batteries. They are 100

Amp hrs and 12 Volts each. We chose these over standard lead acid batteries

because they have a number of advantages: they are completely sealed, so they

can't be spilled, they do not need periodic watering, and they emit no corrosive

fumes, and no equalization charging is required: perfect for rugged, low

maintenance applications. They can also be transported easily and safely by air.

Last, but not least, they can be mounted on their side or end and are extremely

vibration resistant. Initially, we had decided on different batteries; however,

they weighed 150lbs each, and so would have caused significant transportation

problems. We decided to go with the Trojans instead because they are only

66lbs each. Batteries should not be set directly on concrete surfaces as self

discharge will be increased, particularly if the surface gets damp. Adequate

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venting must be provided to minimize explosion hazard if open-cell batteries are

used.

4. Inverter: The inverter converts the DC current stored in the batteries to AC which

can be used by the components of the water purification system. Both the ozone

generators and the pump use AC, so this is the last cog in the power system.

There are several factors that we considered in choosing the type of inverter to

use and they are as listed below.

a. Electric standards and power capacity- reference Specifications.

b. Power quality or wave form- our design uses a pure sine wave which

generates an ideally smooth AC.

c. Internal protection- Our inverter can handle overloads, surge protection

and low voltage shut off.

d. Inverter efficiency in our design is rated 90% and nothing less meaning

10% power loss.

5. Solar Array Mounting- Solar electric arrays are mounted in several unique and

innovative ways. The key factors to consider in the installation of the array are

the tilt angle and array orientation since they affect array performance to a

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significant percentage. The key objective in building our mount surface is a

solidly mounted solar panel array that will with stand all types of weather.

Whatever the mounting system, there is significant need to make sure that the

array modules are restrained and firmly anchored. With that in mind, there are

we decided to purchase a pole mount.

Passive Mount Structure

As shown above, the passive pole structure is ideal for our system. We calculated

sunlight angles and tilt angles to have our solar system mounted onto this kind of

a mount. The only disadvantage with this system in comparison to the Passive

Mount is that the array will not be automatically adjusted to fit the sun’s

position. This design thus demands that the engineers implement the best tilt

angle for the array since this is a set standard.

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3.2 Testing and Analysis

We conducted a variety of tests. We ran a number of battery discharge tests, where we

discharged the batteries under various loads to test the capacity of the battery bank. We also

tested the open circuit voltage of the solar panels to make sure they were within manufacturer

specifications. We logged the incoming current from the panels on different days with varying

solar intensities: cloudy days, sunny days. (See appendix for attached results). The test results

confirmed the outputs we had expected.

Here we see the results of a discharge test under a 260 Watt load, which is equivalent to

the peak load of the water purification system. The batteries performed very well,

lasting for almost nine hours before the low voltage disconnect was triggered.

0

2

4

6

8

10

12

14

16

0:0

0

0:28

0:5

7

1:2

6

1:55

2:2

4

2:52

3:2

1

3:5

0

4:19

4:4

8

5:1

6

5:4

5

6:1

4

6:43

7:1

2

7:4

0

8:0

9

8:3

8

Vo

ltag

e (V

)

Discharge Test with 260 W Load

Voltage (V)

Time (hrs)

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This test was done under a higher load; we wanted to stress the system a little. The

batteries still performed quite well. One thing to note is that these tests were

performed using batteries that were exclusively for testing, not the actual batteries we

were planning to order.

0

2

4

6

8

10

12

14

16

0:00

0:23

0:46

1:09

1:32

1:55

2:18

2:41

3:04

3:27

3:50

4:13

4:36

4:59

5:22

5:45

6:08

Discharge Test with 400 W Load

Voltage (V)

Time (hrs)

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Project Management As a cohesive two-person team, we worked closely together in meeting the project time

line. We also worked closely with the water purification team as a whole in meeting the

specific project time lines as dictated by our Gantt chart.

4.1 Problems

We faced a number of challenges during the implementation phase:

Some of our materials did not arrive on time, which meant that we had to

readjust our schedule slightly.

Since we had no experience with solar wiring, we had to spend a considerable amount

of time researching wire gauges and knowing the proper gauge to use.

During the assembly we realized that we needed to put extra fuses in which caused

more slight delays

The circuit breaker we had ordered did not meet our specifications and had to be

changed. We had some initial difficulty finding the DC circuit breaker in the area.

The order did not include enough battery interconnect cable and certain other wiring

which we had to purchase later on during the assembly.

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4.2 Materials

12V Solar Panels

12/24/48V Charge Controller

300 Ah AGM Battery bank

600W 12V Pure Sine Wave Inverter

Connectors/wiring

4.3 Personnel

We worked closely with the Water Purification team of the Collaboratory during the

project. In a sense, they are our direct clients, although we also worked together as a

team on various non-electrical aspects of the project. Our aim was to extend the scope

of our contribution to the entire project and not just limit it the electrical portions.

We also availed the assistance and guidance of Mr. Steve Frank in towards the solar

aspects, as we did not have much experience in this area. We were also in touch with

members of the Energy team of the Collaboratory, as they have been involved in setting

up solar energy projects and were a valuable source of advice.

4.4 Economic Factors

A solar system in Laguna will be cost effective in the long run, provided they do not get

connected to the power grid in that period. If they do get connected within a period of

three years, then using a generator system will be more cost effective. The prospects of

Laguna getting connected to the grid in three years are remote however.

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Budget

Solar systems have a fundamentally expensive upfront cost that pays up with time. Our

cost analysis project 3 year pay off time. Alongside our cost analysis is a financial

breakdown of our system (See Appendix). Attached in the appendix is a financial

analysis covering the upfront cost of a 375 watt PV system.

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Conclusions To ensure the completion of the project, we enacted several major objectives that

would serve as the project roadmap:

To a PV system that will provide 375 watts for 9 hours a day all year round at

maximum performance as dictated by our system specifications.

To achieve this goal we built a system that will be able to support a 2 to 3

gallon flow rate per minute. In considering low sunlight days, we sized

our battery system to be able to run the system at maximum

performance without having to recharge them for about 3 days at a

minimum. (See Design Calculations).

Our tests results yielded at 2.9 gallon per minute flow rate.

To have a fully functional and ready to implement power source by May 2nd,

2008.

On April 11th, 2008 we completed the entire assembly phase and ran our

first tests.

Fully assembled our system for demonstration and testing purposes.

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To Complete The VWOS installation and maintenance manual

We completed the installation manual and documentation by 21st April

2008.

Completed a detailed financial analysis showing break even points and overall

cost of running the system.

We examined the cost of installing a solar system with battery support to

the cost of using a generator. We compared the upfront cost of installing

a solar system, coupled with the minimal maintenance costs in

comparison to running the entire system on a generator. Our conclusive

analysis led us to believe that a solar system was more cost effective with

time. (See Cost Analysis in Appendix)

To design a simple, effective power source for less than $3000 hundred dollars

including installation cost.

Considering the financial constraints given, we purchased and were able

to assemble a PV system for less than $2500 dollars. With the present

upfront cost for solar energy, the price range for our system fell within a

reasonable standard.

To complete the initial design and integration phase by mid April, 2008.

P a g e | 37

In order to subject the unit to appropriate testing and redesign, we met

the assembly time frame of by April 14th 2008.

Coupled with the assembly, we completed the VWOS Solar Installation

and Assembly Manual by April 21st, 2008.

In accordance with our project time frame, we completed the assembly

training session on the 21st April 2008.

Overall, we feel that our project was a success. We were able to satisfy most of our

starting objectives and have a fully functional system.

P a g e | 38

Future Work Future work will consist of final checks and after that, installation. We designed the

system to allow for easy expansion, which will also be carried out if necessary. The

battery bank needs to be purchased as well. If there is a need for expansion, we would

not recommend wiring any extra modules in parallel as there is already a high enough

current coming through. Instead, we would recommend using both parallel and series

connections in order to keep the current down, as any more current that what comes in

presently will result in significant losses with the current gauge of wire used. Careful

thoughts also need to be given if a redesign is done as the inverter is only rated at 12V,

and wiring a system with any other voltage will destroy it. Also, further testing could be

carried out.

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Bibliography Solar Energy International. (2004). Photovoltaics: Design and Installation Manual. 2004:

New Society Publishers.

P a g e | 40

Appendix Contents Gantt charts (Fall and Spring semester)

Design Diagrams

Design Calculations

Test Analysis

Cost analysis

Budget

VWOS Solar Installation and Maintenance Manual

Assembly Pictures

P a g e | 41

VWOS Solar Installation and Maintenance Manual

TABLE OF CONTENTS

1. Introduction…………………………………………………………………………

….. 2

a. Must know

2. Safety

Precautions…………………………………………………………………….... 3

a. Basic installation safety tips

b. Site Preparation Tips

c. PV Module safety

3. The VWOS Solar

System………………………………………………………………. 8

a. Pictures

b. System Specs

4. Assembly……………………………………………………………………………

….. 4

a. Mounting System

b. Solar Panels

c. Shunt

d. Charge Controller

e. Inverter

f. Batteries

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5. Troubleshooting……………………………………………………………………

…17

6. Appendix

a. Solar Electric (PV) System Installation Checklist

b. System Specs

c. Pictures

Introduction

For installation personnel

1. This manual provides guidelines for installation, but it does not guarantee the

quality of installation work. Please complete all work in a responsible and

professional manner. (All electrical work should be performed by qualified or

trained personnel)

2. Read the installation guide carefully before assembly.

3. Personnel who have trained with the VWOS team only shall only install the

system.

4. The manual gives basic safety standards that can be used on any PV system. A

detailed installation guide goes in hand and in accordance with the VWOS solar

system.

For safe installation work

1. To prevent corrosion, scaling, and freeze damage, it is recommended to use a non-

toxic anti-freeze/corrosion inhibitor in the solar loop.

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2. Stop work during stormy weather. Solar modules can be caught in the wind,

causing you to fall. Ensure the mounting is firm to avoid such scenarios.

3. Never step or sit on the glass surface of a solar module. The glass may break,

resulting in shock or bodily injury. This could also cause module failure.

4. Always use the supplied parts to attach the solar modules and mounts.

5. Use of weaker parts, such as screws that are too short, is dangerous and may

cause the solar modules or mounts to fall.

6. Always use the specified tools. The solar modules or mounts may fall if the

installation is not strong enough, for example when parts are not tightened

sufficiently.

7. If installing on a roof, make sure that sheathing is taken care of to avoid potential

leaks in case of rain.

8. In accordance to meeting the expected performance standards, make use of the

prescribed material for better performance.

9. Do not install system in a location within 0.3 miles from the ocean or any salt

water.

10. Do not install in corrosive locations classified C5 by ISO.

11. Protective earth grounding of the individual photovoltaic modules is achieved by

the securing of the modules to the mounting frames. The assembly instructions

should be closely followed, in order to ensure a reliable ground connection.

12. Install wires and cables with appropriate hardware in accordance with applicable

electrical codes.

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1.1 Safety Precautions

1. Do not drill holes in frame. Do not cut or modify parts or rails.

2. Work under dry conditions with dry tools.

3. Do not stand or step on solar module.

4. Do not install near flammable gases.

5. Do not drop or allow objects to fall onto module.

6. Completely cover solar module with opaque materials when wiring to halt

production of electricity.

7. Keep the back side of solar module surfaces free of foreign objects.

8. Do not use chemicals on solar modules when cleaning.

9. Do not wear metallic jewelry, which may cause electrical shock.

10. Do not touch cable electrical contacts.

11. Do not expose solar modules to sunlight that is concentrated with mirrors, lenses

or similar means.

12. Consult local codes and other applicable laws and statutes concerning required

permits and regulations concerning installation and inspection requirements.

Install solar modules and systems according to applicable code.

13. Product should be installed and maintained by qualified personnel. Keep

unauthorized personnel away from solar modules.

14. Avoid shadowing cells in order to prevent solar module hot spots and/or reduction

in power.

15. Avoid installing modules and mounting system in high corrosion areas.

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Assembly

4a. Mounting System Safety tips

To prevent accidents, safety regulations must be observed. Always take the following

precautions to prevent accidents and damage to the system.

1. Take the following precautions before starting work

- Plan the job and visit the site before starting work.

- On site, do not work alone. Always work with at least one other person.

- Inspect power tools before using them.

2. When conditions make it necessary, tell workers to stop working

- When it is raining, or there is a strong probability that it will start raining.

- Immediately after rain, and when work areas are slippery.

- When high wind conditions exist, or are expected, or when a high wind warning

has been issued.

- When it is snowing, or when there is snow underfoot.

3. Wear appropriate work clothes and protective equipment.

- Work clothes for both the upper and lower body should fit well and allow you to

move freely.

- Always wear protective equipment such as harnesses and lifelines.

- Wear a helmet and secure it correctly.

- Wear non-slip shoes. Shoes get dirty when worn on a roof, so keep the soles clean

P a g e | 46

4. When working in high places wear harnesses and use scaffolding.

- When working at heights of 6 ft or more use scaffolds or other equipment to

ensure stable work platform

- Scaffolds should be designed and erected by a qualified person.

- When it is difficult to erect a stable work platform, install safety nets, wear

harnesses, and take other measures to prevent falls.

4b. PV Modules

Wiring work should be performed according to the provisions of the National Electrical

Code. Grounding work and wiring connections to the inverter should be performed by a

qualified electrician.

The solar array generates electricity whenever it is exposed to sunlight. Be careful when

handling it. There is a danger of shock if you touch the connectors or wires of the electric

cables.

Points to check before wiring

- The solar modules generate electricity when exposed to light. You will need to

wear insulating gloves.

- You will need a multimeter for volts, amps, resistance and continuity capable of

measuring system electrical data.

- Make sure your tools are insulated

Wiring the solar modules

- When you install the solar modules on the mount, never allow an output cable to

be caught between the mount and frame.

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- Solar modules generate electricity when exposed to sunlight thus you should take

care not to short circuit the output cables. The cables can become overheated and

their cable sheaths can melt.

- Ensure the module connectors are fully inserted. There is a risk of malfunction if

they are not pushed in all the way.

- Support output cables so that there is no slack. High winds can blow slack cable

against the mount damaging the cables or even causing a short.

Wiring from solar arrays to the inverter (connector box)

- For wiring through walls, protect the cables with metal conduits, flexible metal

conduits, or other protection. Failure to do so can result in shock and short

circuits. Always use conduit to protect sections of array output cables that are

exposed to sunlight.

- For wiring outdoors, protect cables with PVC conduits, metal conduits or flexible

conduits.

- To prevent shock, tape and label the cut ends of array output extension cables (the

side opposite to the connector side) before connecting to solar module output

cables. Further, tape them again after measuring the voltage of each array.

- To prevent shock when you connect the array output cables to the inverter,

remove the tape one cable at a time as you connect the cables.

Measuring array output voltage

- Set the volt meter measurement range to a DC voltage, greater than the expected

measurement (for example 600 VDC).

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- Keep the plus (+) solar array output cables away from the ends of the minus (-)

cables. Dangerous arcs can occur. (The array output voltage under normal

conditions (clear skies) can be very high.)

Grounding the mount

- To prevent shock, always connect a ground wire from the mounting hardware to

earth.

4c. MNPV Installation manual

Select the location to install your combiner first. Some systems have PV modules

located close to the inverters and or battery system. If this is the case you can

elect to mount the MNPV inside and run each PV string down to the MNPV

inside the house.

For outdoor combiner installation, the combiner can be mounted in the vertical

position or slanted backwards to accommodate 3/12 roof pitch.

All unused holes should be blocked using RTV sealing or some similar goop to

avoid bugs and rain into the box.

See attached drawings for clear illustration of how to go about installing the box.

4d. Solar Charge Controller

A. Quick Start Instructions

Mount the ProStar to a vertical surface allowing space for air flow on top and

below. The heat sink must be in a vertical position.

Make sure the Solar and Load currents do not exceed the ratings of the ProStar

version being installed.

Connect the battery first. Make sure that the Battery Status LEDs blink in

sequence one time. Torque all the ProStar terminals tightly, but do not exceed 35

in-lb.

Connect the battery sense. This is recommended but not required, if the battery is

located more than five meters from the controller.

Connect the Solar. With sunlight, the green Charging LED will light.

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Connect the Load. If there is Fault, the LEDs will begin blinking. Refer to

section…..to indentify the fault.

Select the proper charging for battery in use, Turn the rotary switch with a

screwdriver to the Battery Type printed on the label. The Battery Status LEDs

will blink 1, 2 or 3 times depending on battery type chosen.

For 12 and 24 volt systems, the ProStar will automatically select the system

voltage. If the system is 24 volts, confirm that the battery is above 15.5 volts. The

controller selects 12 or 24 volts at start-up.

Observe LEDs and digital meter to confirm operation.

B. LED Indicators

Charging(LED 1-green)

o On: Battery charging during sunlight(always on during sunlight)

o OFF: Normal during night(off during sunlight indicates the solar reverse

polarity or over current)

Battery Status(LEDs 2-4)

o Green: On indicates battery is nearly fully charged, Blinking indicates

PWM charging(regulation)

o Yellow: On indicates battery at middle capacity

o Red: Blinking indicates a low charge state and a low voltage load

disconnect (LVD) warning. On indicates that the load has been

disconnected(LVD)

Faults(G=green, Y= Yellow, R=red)

o G/Y/R blinking together-battery select fault

o R-Y sequencing- high temperature disconnect

o R-G sequencing- High voltage disconnect

o R/G-Y sequencing-Load short circuit or overload

Installation Steps

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o Allow at least 15-20 cm above and below for air flow

o Check array and battery ratings in respect to standards of the controller

o Connect the batteries first

For 12 volt batteries, charge must be over 8 volts

For 24 volt batteries, must be over 15 volts

Ensure that 3 Battery Status LEDs light up in sequence

Pro star is protected against fault but not reverse battery

connection. Verify polarity of battery connections is right.

Use a small screwdriver to change the battery ratings to the right

type of battery: 1- Gel, 2- Sealed and 3- Flooded.

o Turn off load before connecting it. Run load wires first before operating

the system.

o Confirm grounding and installation connections

4e. INVERTER STARTUP TESTS (hard hat, gloves, and eye protection

recommended)

o Be sure that the inverter is off before proceeding with this section.

o Test the continuity of all DC fuses to be installed in the DC string

combiner box, install all string fuses, and close fused switches in combiner

box.

o Check open circuit voltage at DC disconnect switch to ensure it is within

proper limits according to the manufacturer’s installation manual.

o If installation contains additional DC disconnect switches repeat the step 4

voltage check on each switch working from the PV array to the inverter

DC disconnect switch closing each switch after the test is made except for

the final switch before the inverter (it is possible that the system only has a

single DC switch).

.

o At this point consult the inverter manual and follow proper startup

procedure (all power to the inverter should be off at this time).

o Confirm that the inverter is operating and record the DC operating voltage

in the following space.

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o Confirm that the operating voltage is within proper limits according to the

manufacturer’s installation manual.

o After recording the operating voltage at the inverter close any open boxes

related to the inverter system

4f. Batteries

o This is a very critical part of the system

o Batteries should be stored in a cool dry place with respect to battery

standards

o When wiring batteries, make sure you use equipment that is insulated from

electricity.

o Enough battery current could cause potential harm and death in some

cases. Batteries must be handled with expert care.

6a. Troubleshooting

Factors Affecting Output

1. Standard Test Conditions

Solar modules produce dc electricity. The dc output of solar modules is rated by

manufacturers under

Standard Test Conditions (STC). These conditions are easily recreated in a factory, and

allow for consistent comparisons of products, but need to be modified to estimate output

under common outdoor operating conditions. STC conditions are: solar cell temperature

= 25 oC; solar irradiance (intensity) = 1000 W/m2(often referred to as peak sunlight

intensity, comparable to clear summer noon time intensity); and solar spectrum as filtered

by passing through 1.5 thickness of atmosphere (ASTM Standard Spectrum). A

manufacturer may rate a particular solar module output at 100 Watts of power under

STC, and call the product a ―100-watt solar module.‖ This module will often have a

production tolerance of +/-5% of the rating, which means that the module can produce 95

Watts and still be called a ―100-watt module.‖ To be conservative, it is best to use the

P a g e | 52

low end of the power output spectrum as a starting point (95 Watts for a 100-watt

module).

2. Temperature

Module output power reduces as module temperature increases. When operating on a

roof, a solar module will heat up substantially, reaching inner temperatures of 50-75 oC.

For crystalline modules, a typical temperature reduction factor recommended by the CEC

is 89% or 0.89. So the ―100-watt‖ module will typically operate at about 85 Watts (95

Watts x 0.89 = 85 Watts) in the middle of a spring or fall day, under full sunlight

conditions.

3. Dirt and dust

Dirt and dust can accumulate on the solar module surface, blocking some of the sunlight

and reducing

output. Much of California has a rainy season and a dry season. Although typical dirt and

dust is cleaned off during every rainy season, it is more realistic to estimate system output

taking into account the reduction due to dust buildup in the dry season. A typical annual

dust reduction factor to use is 93% or 0.93. So the ―100-watt module,‖ operating with

some accumulated dust may operate on average at about 79 Watts (85 Watts x 0.93 = 79

Watts).

4. Mismatch and wiring losses

The maximum power output of the total PV array is always less than the sum of the

maximum output of the individual modules. This difference is a result of slight

inconsistencies in performance from one module to the next and is called module

mismatch and amounts to at least a 2% loss in system power. Power is also lost to

P a g e | 53

resistance in the system wiring. These losses should be kept to a minimum but it is

difficult to keep these losses below 3% for the system. A reasonable reduction factor for

these losses is 95% or 0.95.

5. Dc to ac conversion losses

The dc power generated by the solar module must be converted into common household

ac power using an inverter. Some power is lost in the conversion process, and there are

additional losses in the wires from the rooftop array down to the inverter and out to the

house panel. Modern inverters commonly used in residential

PV power systems have peak efficiencies of 92-94% indicated by their manufacturers,

but these again are measured under well-controlled factory conditions. Actual field

conditions usually result in overall dc-to-ac conversion efficiencies of about 88-92%,

with 90% or 0.90 a reasonable compromise.

So the ―100-watt module‖ output, reduced by production tolerance, heat, dust, wiring, ac

conversion, and

other losses will translate into about 68 Watts of AC power delivered to the house panel

during the middle of a clear day (100 Watts x 0.95 x 0.89 x 0.93 x 0.95 x 0.90 = 67

Watts).

6. Sun angle and house orientation

During the course of a day, the angle of sunlight striking the solar module will change,

which will affect

the power output. The output from the ―100-watt module‖ will rise from zero gradually

during dawn hours, and increase with the sun angle to its peak output at midday, and then

gradually decrease into the afternoon and back down to zero at night. While this variation

P a g e | 54

is due in part to the changing intensity of the sun, the changing sun angle (relative to the

modules) also has an effect.

7a Appendix

SOLAR ELECTRIC (PV) SYSTEM INSTALLATION CHECKLIST

Following the completion of each item on the checklist below, check the box to the left of

the item and insert the date and initials of the person completing the item whether that is

the installing contractor or owner-installer. Remember to follow the proper safety

procedures while performing the system installation. The appropriate safety equipment

for each section of the checklist is listed above each section of the checklist.

Before starting any PV system testing: (hard hat and eye protection recommended)

-------- Check that non-current carrying metal parts are grounded properly. (array frames,

racks,

metal boxes, etc. are connected to the grounding system)

-------- Ensure that all labels and safety signs specified in the plans are in place.

-------- Verify that all disconnect switches (from the main AC disconnect all the way

through to

the combiner fuse switches) are in the open position and tag each box with a warning sign

to signify that work on the PV system is in progress.

PV ARRAY--General (hard hat, gloves, and eye protection recommended)

-------- Verify that all combiner fuses are removed and that no voltage is present at the

output of

the combiner box.

-------- Visually inspect any plug and receptacle connectors between the modules and

panels to

ensure they are fully engaged.

-------- Check that strain reliefs/cable clamps are properly installed on all cables and

cords by

P a g e | 55

pulling on cables to verify.

-------- Check to make sure all panels are attached properly to their mounting brackets

and

nothing catches the eye as being abnormal or misaligned.

-------- Visually inspect the array for cracked modules.

-------- Check to see that all wiring is neat and well supported.

PV Installation Guide

PV ARRAY CIRCUIT WIRING (hard hat and eye protection recommended)

-------- Check home run wires (from PV modules to combiner box) at DC string combiner

box to

ensure there is no voltage on them.

-------- Recheck that fuses are removed and all switches are open.

-------- Connect the home run wires to the DC string combiner box terminals in the proper

order

and make sure labeling is clearly visible.

REPETITIVE SOURCE CIRCUIT STRING WIRING (hard hat, gloves, and eye

protection recommended)

The following procedure must be followed for each source circuit string in a systematic

approach—i.e. east to

west or north to south. Ideal testing conditions are midday on cloudless days March

through October.

-------- Check open-circuit voltage of each of the panels in the string being wired to verify

that it

provides the manufacturer’s specified voltage in full sun. (Panels under the same sunlight

conditions should have similar voltages--beware of a 20 Volt or more shift under the

same sunlight conditions.)

-------- Verify that the both the positive and negative string connectors are identified

properly

with permanent wire marking.

-------- Repeat this sequence for all source circuit strings.

-------- Recheck that DC Disconnect switch is open and tag is still intact.

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-------- VERIFY POLARITY OF EACH SOURCE CIRCUIT STRING in the DC String

Combiner Box (place common lead on the negative grounding block and the positive on

each string connection--pay particular attention to make sure there is NEVER a negative

measurement).

--------Verify open-circuit voltage is within proper range according to manufacturer’s

installation manual and number each string and note string position on as-built drawing.

(Voltages should match closely if sunlight is consistent.)

WARNING: IF POLARITY OF ONE SOURCE CIRCUIT STRING IS REVERSED,

THIS CAN START A FIRE IN THE FUSE BLOCK RESULTING IN THE

DESTRUCTION OF THE COMBINER BOX AND POSSIBLY ADJACENT

EQUIPMENT. REVERSE POLARITY ON AN INVERTER CAN ALSO CAUSE

DAMAGE THAT IS NOT COVERED UNDER THE EQUIPMENT WARRANTY.

-------- Retighten all terminals in the DC String Combiner Box.

WIRING TESTS--Remainder of System: (hard hat, gloves, and eye protection

recommended)

-------- Verify that the only place where the AC neutral is grounded is at the main service

panel.

-------- Check the AC line voltage at main AC disconnect is within proper limits (115-125

Volts

AC for 120 Volts and 230-250 for 240 Volts).

-------- If installation contains additional AC disconnect switches repeat the step 11

voltage

check on each switch working from the main service entrance to the inverter AC

disconnect switch closing each switch after the test is made except for the final switch

before the inverter (it is possible that the system only has a single AC switch).

INVERTER STARTUP TESTS (hard hat, gloves, and eye protection recommended

-------- Be sure that the inverter is off before proceeding with this section.

-------- Test the continuity of all DC fuses to be installed in the DC string combiner box,

install

all string fuses, and close fused switches in combiner box.

-------- Check open circuit voltage at DC disconnect switch to ensure it is within proper

limits

according to the manufacturer’s installation manual.

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--------If installation contains additional DC disconnect switches repeat the step 4 voltage

check on each switch working from the PV array to the inverter DC disconnect switch

closing each switch after the test is made except for the final switch before the inverter (it

is possible that the system only has a single DC switch.

-------- At this point consult the inverter manual and follow proper startup procedure (all

power

to the inverter should be off at this time).

-------- Confirm that the inverter is operating and record the DC operating voltage in the

following space.________

-------- Confirm that the operating voltage is within proper limits according to the

manufacturer’s

installation manual.

-------- After recording the operating voltage at the inverter close any open boxes related

to the

inverter system.

-------- Confirm that the inverter is producing the expected power output on the supplied

meter.

-------- Provide the homeowner with the initial startup test report.

SYSTEM ACCEPTANCE TEST (hard hat and eye protection recommended)

Ideal testing conditions are midday on cloudless days March through October. However,

this test procedure accounts for less than ideal conditions and allows acceptance tests to

be conducted on sunny winter days.

------- Check to make sure that the PV array is in full sun with no shading whatsoever. If

it is

impossible to find a time during the day when the whole array is in full sun, only that

portion that is in full sun will be able to be accepted.

------- If the system is not operating, turn the system on and allow it to run for 15 minutes

before taking any performance measurements.

------- Obtain solar irradiance measurement by one of two methods and record irradiance

on

this line: W/m2. To obtain percentage of peak sun, divide irradiance by 1000 W/m2 and

record the value on this line . (example: 692 W/m2 ÷ 1000 W/m2 = 0.692 or 69.2%.)

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Method: Place a single, properly operating PV module, of the same model found in the

array, in full sun in the exact same orientation as the array being tested.

After 15 minutes of full exposure, test the short circuit current with a digital multimeter

and place that reading on this line: Amps.

Divide this number into the short circuit current (Isc) value printed on the back of the PV

module and multiply this number by 1000 W/m2 and record the value on the line above.

Example: Isc-measured = 3.6 Amps; Isc-printed on module = 5.2 Amps; Irradiance = 3.6

Amps/5.2 Amps * 1000 W/m2 = 692 W/m2

-------- Sum the total of the module ratings and place that total on this line WattsSTC.

Multiply this number by 0.7 to obtain expected peak AC output and record on this line

WattsAC-estimated.

-------- Record AC Watt output from the inverter or system meter and record on this line

WattsAC-measured.

-------- Divide WattsAC-measured by percent peak irradiance and record on this line

WattsAC-corrected. This ―AC-corrected‖ value is the rated output of PV system. This

number must be within 90% or higher of WattsAC-estimated recorded in step 4. If it is

less than 90%, the PV system is either shaded, dirty, mis-wired, fuses are blown, or the

modules or inverter are not operating properly.

Example:

A PV system is made up of 20, 100 WattSTC PV modules operating at an estimated

irradiance of 692 W/m2 using the method shown above. The power output is measured to

be 1000 WattsAC-measured at the time of the test. Is this system operating properly or

not?

Solution:

Sum of module ratings = 100 WattsSTC per module x 20 modules = 2,000 WattsSTC.

Estimated AC power output = 2,000 WattsSTC x 0.7 = 1,400 WattsAC-estimated.

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Measured AC output = 1,000 WattsAC-measured.

Corrected AC output = 1,020 WattsAC-corrected ÷ 0.692 = 1,474 WattsAC-corrected.

Comparison of corrected and estimated outputs: 1,474 WattsAC-corrected ÷ 1,400

WattsAC-estimated = 1.05 ≥ 0.9

(Accepted Performance)

A. System Specs

Solar Power Source Specifications

Target System:

System Load : 257 W (±10 %)

Load time/day : 2.2 kWh

Solar Panel Specifications:

12 V Output Voltage

Max. Power : (depends on configuration)

Max. Voltage : 19 V (± 10%)

Max. Current : 7.5 A (± 5%)

Open Circ. Voltage. : 21.7 V (± 5%)

Short Circ. Current : 7.1 A (± 5%)

Max. System Voltage : 750 VDC

Weight : 30 lbs (± 10%)

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Battery Specifications:

Sealed Lead AGM

Voltage : 12 V

Amp-Hrs : 245 A-H (± 10%)

Dimensions:

Length : 25‖ (± 10%)

Width : 15‖ (± 10%)

Height : 15‖ (± 10%)

Weight : 150 lbs (± 10%)

Inverter Specifications:

Cont. Power rating : 300 W

Output Waveform : Pure Sine Wave

Peak Power rating : 600 W, 10 minutes (± 10%)

DC Input Voltage : 10.0 V – 15.5 V

AC Output Volt. (RMS) : 115 V (± 10%)

AC Output Frequency : 60 Hz (± 0.1%)

Peak Efficiency : 90 % (± 5%)

Low Voltage Disc (LVD) : 10.5 V (± 0.5%)

Low Voltage Reconnect : 11.6 V (± 0.5%)

LVD Warning : 10.8 V (± 0.5%)

High Voltage Disc : 15.5 V (± 0.5%)

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High Voltage Reconnect : 14.5 V (± 0.5%)

Charge Controller Specifications:

Type : MPPT

Output Current Rating: 25 A (± 10%)

System Voltage : 12 V

Max Open Circ. Volt. : 30 V

Charge Volt. Adjust. : 13 V – 16 V

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Pictures

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Cost Analysis

Generator

Cost/Period $ 750

Interest Rate 10%

Year Present Worth

Year Future Worth

1 ($681.82)

1 ($750.00)

2 ($1,301.65)

2 ($1,575.00)

3 ($1,865.14)

3 ($2,482.50)

4 ($2,377.40)

4 ($3,480.75)

5 ($2,843.09)

5 ($4,578.83)

6 ($3,266.45)

6 ($5,786.71)

7 ($3,651.31)

7 ($7,115.38)

8 ($4,001.19)

8 ($8,576.92)

9 ($4,319.27)

9 ($10,184.61)

10 ($4,608.43)

10 ($11,953.07)

11 ($4,871.30)

11 ($13,898.38)

12 ($5,110.27)

12 ($16,038.21)

13 ($5,327.52)

13 ($18,392.03)

14 ($5,525.02)

14 ($20,981.24)

15 ($5,704.56)

15 ($23,829.36)

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Gantt Charts

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Testing Results & Raw Data What to test for:

- Length/ Duration to charge the test batteries to maximum capacity

- Length/ Duration of batteries to run a dummy load of similar characteristics to the actual

system over a projected time frame

- Measure an average array output voltage

- Monitor average heat generated and compare to factory standards

- Determine solar panel reactions to different sunlight intensity

- Determine overall charging effects based upon sunlight intensity on the entire system

Test Analysis:

- Yield maximum amount of load that the system can handle and run at least 90%

efficiency

- Maximum amount of discharge time at least with 90% of performance (in respect to load)

- Number of days/hours of running the system on batteries without requiring a recharge

- Determine number of batteries to support a 3 to 5 day of system performance at reduced

% efficiency

- Data projection analysis to determine overall potential performance of the system

Expected Results:

- Project a potential recharge time frame

- Project best performance of the system if powered by batteries

- Project solar modules % performance compared to factory ratings

- Project number of batteries needed to sustain the system for 3 to 5 days

- Project overall battery performance without required recharge

Order of Tests:

- Battery Charge Time test

- Solar Module Voltage output test

- Integrated Tests

- Overall system performance test on batteries

- Battery discharge time subject to dummy load

- Heat tests

- Sunlight Intensity Effects Test

Conclusion:

- Potential tests will facilitate in system redesign

- System testing will help the VWOS team determine the kind of Solar batteries to

purchase

- Overall system performance, despite being a projection, will give the VWOS Installation

Team a rough idea of what to expect

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discharge time frame at minimal battery charge Time(Am) voltage Flow Rate Panel Amps Power=VI Resistance

9:50 14.1 2.9 13 183.3 1.084615

9.52 13.9 2.9 12.2 169.58 1.139344

9.53 13.8 2.9 11 151.8 1.254545

9.55 13.7 2.9 10.4 142.48 1.317308

9.58 13.6 2.9 10 136 1.36

9.59 13.4 2.9 14.1 188.94 0.950355

10 13.5 2.9 14.3 193.05 0.944056

10.01 13.4 2.9 14.2 190.28 0.943662

10.02 13.5 2.9 14.2 191.7 0.950704

10.03 13.5 2.9 13.9 187.65 0.971223

10.04 13.5 2.9 13.4 180.9 1.007463

10.06 13.5 2.9 14.2 191.7 0.950704

10.09 13.5 2.9 13.7 184.95 0.985401

10.12 13.5 2.9 13.8 186.3 0.978261

10.13 13.5 2.9 13.9 187.65 0.971223

10.14 13.5 2.9 13.5 182.25 1

10.17 13.5 2.9 13.9 187.65 0.971223

10.2 13.5 2.9 14.2 191.7 0.950704

10.23 13.5 2.9 13.9 187.65 0.971223

10.26 13.5 2.9 13.7 184.95 0.985401

10.29 13.5 2.9 13.9 187.65 0.971223

10.32 13.5 2.9 14.1 190.35 0.957447

10.35 13.5 2.9 14.3 193.05 0.944056

10.38 13.5 2.9 14.2 191.7 0.950704

10.41 13.5 2.9 13.8 186.3 0.978261

10.44 13.5 2.9 13.6 183.6 0.992647

10.47 13.5 2.9 14.1 190.35 0.957447

10.51 13.5 2.9 14.2 191.7 0.950704

10.52 13.5 2.9 14.3 193.05 0.944056

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0

2

4

6

8

10

12

14

16

0:00

0:28

0:57

1:26

1:55

2:24

2:52

3:21

3:50

4:19

4:48

5:16

5:45

6:14

6:43

7:12

7:40

8:09

8:38

Vo

ltag

e (V

)Discharge Test with 260 W Load

Voltage (V)

Time (hrs)

0

2

4

6

8

10

12

14

16

0:0

0

0:2

3

0:4

6

1:0

9

1:3

2

1:5

5

2:1

8

2:4

1

3:0

4

3:2

7

3:5

0

4:1

3

4:3

6

4:5

9

5:2

2

5:4

5

6:0

8

Discharge Test with 400 W Load

Voltage (V)

Time (hrs)

P a g e | 78

y = -4.399x + 73.11R² = 0.319

0

2

4

6

8

10

12

14

16

13.2 13.4 13.6 13.8 14 14.2

Approximated Resistance

y = 0.914x + 174.1R² = 0.012

0

50

100

150

200

250

0:00 0:00 0:00 0:00

Power Over Time

Power Over Time

Linear (Power Over Time)

P a g e | 79

Budget

Budget

Item Quantity Price/unit Amount

Kyocera KC125G 125W 12V Solar Panel 3

$ 591.69

$ 1,775.07

ProStar Charge Controller 1 $ 178.00

$ 178.00

600W Samlex Inverter 1 $ 276.58

$ 276.58

Trimetric Battery Monitor 1

$ 135.24

$ 135.24

12 Amp Circuit Breaker 3 $ 10.92

$ 32.76

MNPV Combiner Box 1 $ 74.76

$ 74.76

500A, 50mV Shunt 1 $ 20.50

$ 20.50

Wiring & Misc

$ 134.24

Single Tier Pole Mount 1

$ 284.40

$ 284.40

Shipping & handling

$ 89.12

Total

$ 3,000.67