THE PENNSYLVANIA STATE UNIVERSITYSCHREYER HONORS COLLEGE

THE SCHOOL OF ENGINEERING DESIGN, TECHNOLOGY, ANDPROFESSIONAL PROGRAMS

DEVELOPMENT OF AN APPROPRIATE SOLAR AND WIND HYBRID CHARGING STATION FOR ELECTRIC VEHICLES

IN DEVELOPING COUNTRIES

ERIC MICHAEL SAUDER

Fall 2008

A thesissubmitted in partial fulfillment

of the requirementsfor a baccalaureate degreein Mechanical Engineering

with honors in Engineering Design

Reviewed and approved* by the following:

Andrew S. Lau Associate Professor of Engineering Thesis Supervisor

Thomas H. Colledge Assistant Professor of Engineering Design Thesis Supervisor

Richard F. Devon Professor of Engineering Design Honors Adviser

*Signatures are on file in the Schreyer Honors College.

We approve the thesis of Eric Michael Sauder:

Date of Signature

_______________________________ ______________ Andrew S. Lau Associate Professor of Engineering Thesis Supervisor

_______________________________ ______________ Thomas H. Colledge Assistant Professor of Engineering Design Thesis Supervisor

_______________________________ ______________ Richard F. Devon Professor of Engineering Design Honors Adviser

9-3087-7017

Abstract

Mustard Seed Communities (MSC) is a faith based non-profit organization working in

Jamaica to provide care for mentally and physically disabled youth. MSC began a partnership

with Penn State to develop sustainable technologies for Jacobs Ladder a new care facility for 500

residents. Until the donation of two golf carts, the Jacobs Ladder operators were having

problems getting caretakers to travel the final mile into the site every morning. The path is

dangerous, and taxi drivers charge exorbitantly. Jacobs Ladder operators identified the charging

of these electric vehicles as a significant need for the development of the site.

A solar and wind hybrid charging station was designed to take advantage of seasonal

wind and sun. According to the predicted vehicle usage data, estimations of vehicle and charger

efficiencies, the charger is required to generate two kilowatt hours daily. The charge demand will

be met with a wind turbine rated for 400 W, and a 260 W solar array. The charge storage is

designed to allow the vehicles to be in operation during the day, and onboard vehicle batteries

during the night. To increase the versatility of the charging station, the direct current is inverted

to 110 V alternating current receptacles.

The charing station will be constructed on the roof of the site library, built by Penn State

University in Fall 2008. The solar panels will help to shade the roof of the library, cooling the

structure. To promote the continued sustainability of the charger, the station will be installed by

Students from the University of Technology (UTech) in Jamaica, providing a local knowledge

bank capable of maintaining the energy system. After successful installation, MSC will host a

one day alternative energy conference. University students from Penn State and UTech, local

businesses, and curious neighbors will join to reassemble portions of the charger, and share

knowledge about alternative energy technologies.

Keywords

Alternative Energy Systems, Solar, Wind, Hybrid Power System, Renewable Energy,

Sustainability, Jacobs Ladder, Mustard Seed Communities, Jamaica, Charge Controller, Inverter,

Lead-Acid Batteries, Solar Panels Wind Turbine, Sustainable Community, Appropriate

Technology, Shipping Container

Table of Contents2. Introduction 1

2.1 Project Background Information 12.1.1 Mustard Seed Communities 12.1.2. Jacobs Ladder 22.1.3 Bauxite Mining: A Local Problem 22.1.4 Future Goals For Jacobs Ladder 32.1.5 Preliminary Community Assessment of Jacobs Ladder 4

2.2 Project Definitions 42.2.1 Problem Statement 42.2.2 Project Goals 52.2.3 Project Planning 5

3. Project Needs and Specifications 63.1 Customer Input 63.2 Determination of Design Specifications 8

4. Preliminary Research 84.1 Solar Photovoltaic System Sizing Research 8

4.1.1 Science of Solar Photovoltaic Cells 84.1.2 Types of Solar Modules 84.1.3 Solar Insolation 94.1.4 Array Orientation 94.1.5 On-Grid and Off-Grid Systems 104.1.6 System Components 104.1.7 System Sizing 11

4.2 Charge Storage Research 125. Concept Development 12

5.1 Existing Product Search 125.2 Problem Decomposition 145.3 Preliminary Design Concepts and Ideation 145.4 Charge Storage Design Concepts 15

5.4.1 Description of Concepts 155.4.2 Option 1: DC to AC 155.4.3 Option 2: DC With Storage 165.4.4 Option 3: Onboard Storage 16

5.5 Charge Storage Concept Selection 17

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6. System Level Design 186.1 System Sizing 18

6.1.1 Vehicle Usage 186.1.2 Estimated Vehicle Efficiency 196.1.3 Available Energy: Local Solar Insolation 206.1.4 Anticipated System Efficiencies 206.1.5 System Load Sizing Calculations 21

6.2 Available Charge Sources 216.2.1 Meeting the Power Needs with Photovoltaics 216.2.2 Available Wind Energy Production Resources 226.2.3 Advantages and Disadvantages of Hybrid Power Systems 226.2.4 Mustard Seed Wind Development Plans 236.2.5 Wind Availability at Jacobs Ladder 23

6.3 Station Location Concepts: Finding the Optimum Placement 236.3.1 Option 1: Site Entrance 236.3.2 Chapel 246.3.3 Demonstration Village 25

6.4 Station Location Selection 256.5 Station Configuration Concepts: A Functional Design 26

6.5.1 Mounted on Existing Building 266.5.2 Mounted on Proposed Library 266.5.3 Ground Mount 27

6.6 Station Configuration Selection 27Detailed Design 27

7.1 Station Design: The Charge Sources 287.1.1 Solar Array 287.1.2 Solar Integrated Green Roof 287.1.3 Solar Array Mounting Configuration 297.1.4 Wind Turbine 317.1.5 Wind Turbine Placement 31

7.2 Station Design: Processing Electronics 337.2.1 DC Breaker Box 337.2.2 Wire Sizing Calculations 337.2.3 Charge Controller 347.2.4 Battery Bank 357.2.5 Inverter 36

ii

7.3 Station Design: The Charger - User Interface 387.3.1 Benefits of an AC Receptacle 387.3.2 Golf Cart Charger 38

7.4 Station Overall System Design 387.4.1 Charging Unit Placement 387.4.2 Electrical Component Arrangement 397.4.3 Solar Charging Station Rack Mount 40

7.5 Project Budget and Cost Analysis 41Implementation: Jamaica Design-Build 41

8.1 Overview of Design Build Week 418.2 Murphys Law 41

8.2.1 Weather 418.2.2 Where are the Solar Components? 42

8.3 Revised Plans 428.3.1 Theory of Appropriate Technology 428.3.2 Installation and Instruction Manual 438.3.3 Developing Local Connections 438.3.4 Future Alternative Energy Conference 44

8.4 Results of Design-Build Week 448.4.1 Placement and Finishing of Container Library 448.4.2 Completed Library Interior 458.4.3 Identification of Electrical Vehicle Specifications 46

Conclusions 469.1 Experiences and Lessons Learned 469.2 Improvements: A Marketable Design 46

9.2.1 A Justification for Alternatives: The Cost of Power 469.2.2 An Analysis of the Project Costs 479.2.3 The Redesign 48

9.3 Feasibility of Implementing Design in Developing Nations 509.4 Personal Impact of Development Work 50

10. Acknowledgments 51Appendix 1

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2. Introduction 2.1 Project Background Information2.1.1 Mustard Seed Communities

Mustard Seed Communities (MSC) is a faith-

based non-profit organization working in central Jamaica

to care for mentally and physically disabled young

adults.1 Although care facilities for the disabled exist in

Jamaica, they do not continue care for individuals after

reaching the age of 18. MSC operates seven sites on the island, striving to build a community of

caring, sharing, and training.2 The goals of MSC are to provide exceptional care for disabled

individuals, present them with opportunities to develop skills, and to live in an encouraging

community setting.3

Funding for MSC comes primarily from donors and supporting congregations abroad.

To build this funding base, and to decrease the operation costs of their sites, MSC attempts to use

sustainable technologies in their communities. These technologies are able to reduce the financial

strain on operation costs by replacing previously

outsourced tasks with local products.2 At the

Jerusalem! site in Spanish Town, MSC is cultivating

sustainable agriculture programs to feed the

residents. At the My Fathers House site in

Kingston, MSC raised chickens to provide a source

of protein for the residents, and used the manure to

provide energy for cooking.4

Figure 1: MSC LogoA

Figure 2: Jerusalem! resident participating in MSC sustainable agricultural development

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2.1.2. Jacobs Ladder

Mustard Seed approached Penn State in

the Fall of 2007 to design and implement

sustainable technologies at the newest MSC site,

Jacob's Ladder. The new site will be the largest

care community operated by MSC when fully

developed. Five-hundred residents will live in

one-hundred cottages, and as many as one-

hundred caretakers and staff will work at the site daily. 5 Jacobs Ladder will require more

planning, and conscious design than MSC has needed on previous projects.

2.1.3 Bauxite Mining: A Local Problem

MSC hopes to develop technologies on the one-hundred acre Jacobs Ladder site that can

be replicated for surrounding poor Jamaicans. Like many areas in Jamaica, Jacobs Ladder once

had large deposits of Bauxite, the primary aluminum ore. Although mining operations

terminated at the site in the 1970s, the site remains pocketed with deep depressions.2 Jamaican

legislation specifies a maximum slope for mined bauxite pit walls and requires the land to be

returned to a grazing pasture, however, these lands are often lack fertility.6

Jacobs Ladder is located in a remote area of the Blue Mountains of Central Jamaica, just

north of Moneague, and approximately ten miles South of Ocho Rios. This mountainous area

contains the largest deposits of bauxite on the island, and is also home to many of the nations

poorest people. For many, the reclaimed mines are the only affordable lands for their farms and

homes. As a result, the problems existing at Jacobs Ladder: poor soil for crops, limited energy

resources, and scarce water supplies, are very real and practical problems for many Jamaicans.2

Figure 3: Homes at Jacobs Ladder

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2.1.4 Future Goals For Jacobs Ladder

As a service to their community, MSC hopes to make the Jacobs Ladder site a facility

where local community members can learn about the sustainable technologies that helped relieve

these problems. Through conversations with Mustard Seed planners, site operators, and staff,

Penn State is hoping to develop solutions that promote sustainability and increase the quality of

life for the residents and workers at the Jacobs Ladder site.2

Figure 5: Jacobs Ladder Site - Developmental Concept PlanC

Figure 4: Location of Jacobs Ladder SiteB

Jacobs Ladder

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2.1.5 Preliminary Community Assessment of Jacobs Ladder

Penn State students traveled to Jacobs Ladder on two community assessment trips in the

Spring of 2008. After conducting a community survey and customer needs analysis at the Jacobs

Ladder, it was determined that the energy demands of transportation was a significant problem

facing further development of the site. Access

is provided by a one mile long, pothole filled,

dirt haul road used during mining. Staff

workers can afford the taxi fares from the

nearby towns to mine entrance; however, taxi

drivers charge exorbitant amounts to travel the

final mile into the site. Workers do not feel safe

walking this road, as people have been robbed and mugged there in the past, but are forced to

because no transportation is available. Inclement weather can also make the long walk a

miserable experience for the staff. MSC was finding that these factors would occasionally keep

staff from coming to work. At a care facility, where all workers are needed to take care of the

residents, MSC must make every effort to assist their workers in coming to work. To do this,

MSC has purchased electric powered golf carts to shuttle workers from the entrance. Power has

been provided, but the service is not regular. Site operators expressed the need for a reliable

means to charge the electric transport vehicles at Jacobs Ladder.7

2.2 Project Definitions2.2.1 Problem Statement

To incorporate alternative energy and improve the transportation at the Mustard Seed

Communities Jacob's Ladder site, design an appropriate charging station to power existing

electric golf carts. The design must allow for the carts to be operated for transportation

throughout the day.

Figure 6: Students Conducting Site Assessment

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2.2.2 Project Goals

The project is defined and driven by the following three goals:

I. Integrate sustainable technologies into the Jacobs Ladder site.

II. Improve transportation systems for staff.

III. Design a simple and appropriate charging station for site vehicles.

2.2.3 Project Planning

Penn State engineers have been working with site operators and planners at MSC to

determine the course of action for the University involvement with Jacobs Ladder. This is a pilot

project, and will be the first Penn State design-build project to be integrated with the Jacobs

Ladder site.

To ensure that the needs of the customer are met, design specifications are developed

according to their needs, and that an objective design and implementation are chosen, a project

planning diagram has been developed.

Figure 7: Project Planning Diagram Showing Steps of Design Process

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When beginning a design-build project, it is important to assess the possible risks

encountered throughout the duration of the work, from preliminary planning to final

development. International projects working with limited time and budget constraints face

many challenges and risks. These are listed below in the Risk Assessment Figure 8.

Figure 8: Risk Assessment Table

3. Project Needs and Specifications3.1 Customer Input

The project will meet the needs of two primary customers, both long-range MSC

planners, and MSC site operators. Although these two groups both have the same end goal of

providing care for handicapped youth and young adults, they envision different operational

paths. Complete customer needs information can be found in Appendix E.

Long-Range MSC Planners

The Long-Range MSC Planners are geographically separated from the day to day

operations at the Jacobs Ladder site, although an individual in this role does not immediately see

the impact of his or her decisions on the site, with proper communication, these individuals are

able to develop successful goals for site development.

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MSC Site Operators

Matthew Moran

Students from Penn State University began working with Mustard

Seed Communities in the Fall of 2007. Matthew Moran is the United States project

relations director for Mustard Seed, based in New York. He contacted the University

beginning a partnership to develop sustainable initiatives into the site, with hopes

that Jacobs Ladder would become a community showcase of sustainable and

renewable technologies.

Brother Anthony

Brother Anthony is the site operator for the MSC Jacobs Ladder.

Through two visits, Brother Anthony communicated the need for improved

transportation for staff workers to and from the site.7

Clyde Ramkissoon

Clyde coordinates supplies, and manages many of the day to day

needs for all of the Mustard Seed Jamaica sites. When questioned about Brother

Anthonys golf cart request During a March 13, 2008 meeting, Clyde informed the

Penn State engineers that Jacobs Ladder would be receiving a shipment of two

electric powered golf carts to be used for transportation on and to the site.4

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3.2 Determination of Design Specifications

The customer needs have been compiled into a Quality Function Deployment (QFD)

Matrix. This tool is used to translate the customer needs into engineering specifications, which

can then be used to develop the design concepts. The QFD matrix can be found in Appendix F.

4. Preliminary Research4.1 Solar Photovoltaic System Sizing Research

To meet the sustainability design objectives expressed by the Mustard Seed planning

staff, alternative sources will be used to provide the energy required to charge the electric golf

carts used on site.

4.1.1 Science of Solar Photovoltaic Cells

Solar cells generate power by absorbing the energy of photons from the Sun. When a

photon strikes the surface of a solar cell, electrons are transferred through the cell, and a

measurable current is formed. This process is known as the photoelectric effect, and it is the basis

for solar power. The total power produced by a solar module is limited by the total amount of

solar energy, in the form of photons, striking the surface of the panels.8

4.1.2 Types of Solar Modules

Three types of solar modules are commonly used to generate electricity. A

polycrystalline cell is created by chemically treating thinly sliced silicon sheets. Monocrystalline

cells are cut in the same manner, but are uniquely sliced from a single crystal of silicon. Though

thin film panels lack the efficiency of the crystalline cells, the thin film technique is becoming

more common because the coating can be deposited cost effectively using similar techniques to

an ink jet printer.8

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Figure 9: From Left to Right: Monocrystalline, Polycrystalline, and Thin Film CellsD

4.1.3 Solar Insolation

Solar insolation can be thought of as the solar potential of a region, and is typically

expressed as the ideal number of kilowatt hours per square meter per day. For example, if a

region has a solar insolation of 4.5, a solar panel (with 100% efficiency) could produce 4.5 kWh in

one day of operation.8 It is important to remember that solar panels seldom operate at

efficiencies better than 20%.9

4.1.4 Array Orientation

The orientation of a solar array is important

to maximize the total power output of the system. In

the course of the year, the altitude of the Sun may

vary greatly depending on the latitude of the

installation site. In order to maximize the power

generation capabilities of a solar array, some

mounting structures are constructed to adjust angle

throughout the year. As a general rule, the optimum annual altitude angle for a solar panel is the

degrees latitude of the installation site.8 For example, a solar array installed in State College, PA

(40 48' N 77 52' W) would be installed at approximately 41 degrees from horizontal.10

Figure 10: Operable Solar WindowE

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4.1.5 On-Grid and Off-Grid Systems

Alternative energy systems fall into one of two categories: grid-connected, and off-grid

power systems. Grid-connected systems are used to replace a portion of the power provided by

the energy companies. Users installing grid-connected systems are typically attempting to cut

their energy costs by reducing the quantity of power purchased from the power companies. Off-

grid systems are able to deliver electricity to users far from power lines.8 In many remote areas,

the cost of running an electric cable from the electric service can be insurmountable. Here, off-

grid systems can be used to provide the required power. Off-grid systems are relatively simple.

They only require a charge generation source, and typically utilize some form of charge storage.

4.1.6 System Components

A charge generation and storage system has several required components: a charge

source, a charge storage, and a charge monitoring device.

Charge Sources

Solar panels and wind turbines are commonly used charge sources for alternative energy

systems. These devices are relatively inexpensive, require no input fuel, and little maintenance.

Charge Storage

Although the energy produced by a charge source can be used immediately by a load,

few systems are sized exactly to match the load. A charge storage is often utilized to build a

reserve of power which can be used as needed. An example of a system not requiring a charge

storage would be a solar powered attic fan. The fan would only operate during the brightest sun

lit hours of the day. This is an ideal schedule for an item such as fan, where the only necessary

run time is during the heat of the day. Systems must be carefully evaluated to determine if a

charge storage device is necessary.

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Charge Monitoring

If a charge storage device is utilized, a control system is usually required to monitor the

charge state of the storage. These devices, called charge controllers, often contain

microprocessors that can determine what to do with the incoming charge: store it or dissipate the

excess. More sophisticated charge controllers offer monitoring options to determine total power

production.

4.1.7 System Sizing

The ideal off-grid solar power system is designed to store at least all of the charge

produced on a sunny day, and preferably enough to carry the loads through a few days of poor

electric generation potential. All system sizing begins with a thorough analysis of the load.

Whenever possible, the load should be reduced. Load reductions can dramatically decrease the

cost of alternative energy systems. Different charge storage scenarios also require additional

considerations to determine the total amount of charge storage demanded by the system. For

example, electrochemical batteries will last longer if not discharged completely. A common

recommendation for the regular, or cycling, depth of discharge of a battery is 50%. This means

that the total charge storage potential of the battery is only half of the listed to avoid over

discharge of the battery.8

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4.2 Charge Storage Research

Several methods exist for storing the large amounts of charge needed to power a golf

cart. Of these, the most feasible have been chosen and are described below.

Batteries

Batteries utilize electro chemical reactions to store energy. Lead-acid batteries are

the most common batteries used for storage in small-scale alternative energy systems. Lead

dioxide (PbO2) is used for the cathode, metallic sponge lead (Pb) is used for the anode, and the

electrolyte is a mixture of sulfuric acid (H2SO4) and water. A single cell exhibits a nominal

voltage of 2.1 V. These cells are then combined in series to sum voltages to the desired battery

voltage. Commonly six cells are used to form a 12 VDC battery.8

Capacitors

Ultracapacitors differ from batteries as they store charge between solid state

materials, instead of through electrochemical reactions. This allows ultracapacitors to discharge

quickly and deeply without damage to the capacitor. Though ultracapacitors have many ideal

operating characteristics, their cost and must be lowered, and reliability improved before their

wide-spread usage in alternative energy systems.12 F

5. Concept Development5.1 Existing Product Search

Many electric vehicles are designed to meet some portion of their electrical demand with

alternative power sources. Many of these systems utilize solar panels to generate the charge

needed for powering the vehicles. These various designs can be used as benchmarks to rate the

success of the golf cart charging system for Jacobs Ladder. Following are some of the best

competing products:

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Sunray Solar Roof Kit

The Sunray Solar Roof Kit is sold through the Cruise Car golf cart company of

Sarasota, Florida. The kit utilizes a 180 watt panel to supply a current of three amperes at 60

volts. A charge controller regulates the charging of the onboard cart batteries. The panel is

integrated into a roof replacement kit which can be purchased for $1895.00.12 The company

claims that the cart can travel 30% farther because power is constantly being supplied to the

batteries.13

Santa Monica 2.1 kW Solar Electric Vehicle Charging Station

Electric vehicles were first marketed in Arizona and California in the 1997 model

year.4 To prepare for these new vehicles, several cities began incorporating solar charging stations

for electric vehicles into the plans for new development areas. Some of these, such as the 2.1 kW

charging station in Santa Monica, California utilized solar photovoltaic cells to provide the

necessary power for the charging of seven electric vehicles.5 The station is located near, and grid

connected to, the Santa Monica City Hall building. The photovoltaic panels provide a shaded

parking stall for the electric vehicles they charge, and incorporate educational displays to

demonstrate the power generated.4

Solar-Shell Electric Bike Charging Station

The Solar-Shell is an enclosure that provides shelter and power for two electric

bicycles. The Shell uses solar panels to charge a 12 VDC battery bank. Charge is converted from

the DC battery storage back to AC with an inverter, allowing for any 110 VAC bike charger to be

used inside the station. The unit retails for $2,700. 6

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5.2 Problem Decomposition

A black box model is a simple tool used to determine the input and output parameters.

Regardless of the specific design used for the charging station, these components must be present

for the charging station to function. An important result of the black box model is determining

the desired outputs, and required inputs. The system outlined below will produce a charged

vehicle, and allow for a means to monitor the charge state of the vehicle given an input of charge,

here from solar energy.

Figure 11: Black Box Model

5.3 Preliminary Design Concepts and Ideation

Ideation is the process of collecting rough

ideas and gathering them into design concepts. In

the weeks after the community assessment site visit,

ideas were generated, and developmental concepts

were produced to match the functions described in

the black box model. The charging system shown

in figure 12 was one of the first complete concepts

for a stand-alone charging station. Figure 12: Preliminary Charger Concept

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5.4 Charge Storage Design Concepts5.4.1 Description of Concepts

Several charging options and current configurations could be used to deliver charge to

the golf carts at Jacob's Ladder. The following three concepts were developed through the

ideation and external research processes. Some of the advantages and disadvantages of the

concepts are also discussed to highlight the most important features of each design.

5.4.2 Option 1: DC to AC

The direct current (DC) produced by the solar array would be stored in a battery bank to

allow charging to take place at night, when the vehicle would not be in use. The batteries would

be protected from overcharge or overdraw by a charge controller. The current would be

transformed from direct to alternating current (AC) with an inverter. After the inverter, the

current will be the same as nominal household current at 110 V, 60 Hz, and can be used to power

a receptacle. This design allows for the most versatile end use because any AC appliance or

device could be plugged into the AC receptacle. If the charging station is located in a remote part

of the site, work lights, tools, and other equipment could be powered by the charging station.

Although the design is not complex, adding an inverter adds complexity, opportunity for

equipment failure, and added difficulty in servicing a broken system.

Figure 13: DC - AC Charge Storage Concept

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5.4.3 Option 2: DC With Storage

The DC to DC storage design allows charge to be delivered to the golf cart without the

incurring the losses of inverting the charge current twice, once to operate the AC charger, then

back to DC within the commercial charger unit itself. This design also avoids the complexity and

cost of the inverter. The charge controller monitors the state of the batteries, as the bank is

charged by the DC power generated by the solar array. In the evenings, the electric vehicle is

plugged directly into the charge controller load circuit, and is charged by the stored energy in the

batteries. This arrangement cannot be used to power anything except golf carts with a similar

voltage. No tools or other AC devices can utilize power generated by the charging station. This

is beneficial because it focuses the use of the charging station, and guarantees that the station will

be able to charge the vehicles it was designed for. No other devices can steal power intended for

the vehicle charge.

Figure 14: DC - DC Storage Concept

5.4.4 Option 3: Onboard Storage

Instead of using a fixed-location charging station, a solar array could be placed directly

on the roof of the electric vehicles. This system would not likely provide enough power to

completely recharge the vehicle, however, it would be able to extend the traveling range of the

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cart, or lessen the required amount of charge time in the overnight hours. A mobile power source

would also help if the vehicle ran out of charge while far away from the charging station. The DC

solar array would be connected to the batteries of the cart through a charge controller. The

system is simple and inexpensive, however, it can not meet the entire power demand of the

electric vehicle. The vehicle must also always be in direct sunlight for charging to take place.

Figure 15: DC With Onboard Storage Concept

5.5 Charge Storage Concept Selection

Several choices in the design process require an objective, detailed analysis of the factors

influencing the final decisions. For these, the decisions were made with the help of concept

selection matrices. The Analytical Hierarchy Process (AHP) matrix is used to weight the

importance of each design criterion. This weight is then used with the concept selection matrices

to determine which design concept is chosen. The AHP and concept selection matrices can be

found in Appendix G.

After establishing the weight of each design criterion, it was found that the

demonstration value and versatility of the charging station were the most important criterion for

designing the method of charge storage. The heavy weight of these, led to the selection of the DC

to AC charge storage system. This charger model will function similarly to the Solar Shell Electric

Bike Charging Station. An inverter will be used to convert the DC power back to AC. The

versatility of this design will allow for any AC device to operate from the output of the inverter.

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The matrices revealed that the charger must be able to perform a wide variety of tasks, though

specifically designed for powering the golf carts.

6. System Level Design6.1 System Sizing6.1.1 Vehicle Usage

The primary use for the golf carts at Jacobs Ladder is to shuttle workers to and from the

main road. The road is known to be dangerous, and when the weather is stormy, workers will

not walk into the site. At a care facility like Jacobs Ladder where the majority of the residents

require constant care, it is essential that as many staff as possible arrive for work.

The path that workers must traverse is one mile long dirt road, constructed for bauxite

mining operations. The location of the road is shown in figure 16. Anticipated use of the golf cart

is to make two shuttle trips to the road and back in the mornings, and two shuttle trips in the

evenings, as well as some light random travel about the site throughout the day. The estimated

daily total for vehicle use is approximately ten miles.

Figure 16: Location and length of road to Jacobs LadderB

The site workers are currently used to having the electric vehicle available at any point

throughout the day, and are not accustomed to charging the vehicle at any point through the

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working hours of the day. Although they may be willing to change habits, the charging station

should be designed to meet their needs, not to change their customs. This requires the station to

have the charge storage capabilities to hold the energy needed to charge the golf carts through

the night.

6.1.2 Estimated Vehicle Efficiency

At the time of design, the golf cart make and models used on site were unknown. To size

the system without this information, estimations were conducted to determine the cart efficiency

based on hypothetically similar electric vehicles. The carts were acquired by donation, therefore

each cart will likely be of unique. The following figure is a comparison of several electric vehicle

efficiencies compiled by the Colorado University Solar Decathlon Team. Included is a wide range

of electric vehicle types. Though many are much heavier than a golf cart, the assumed

inefficiencies in the golf carts on site may make up for the weight difference.

Figure 17: Comparison of several electric vehicle efficiencies14

It will be assumed that the golf carts operate at an efficiency of 5 miles/kWh for

calculations to develop the necessary power requirements. Using the estimated trip distance, trip

frequency, and vehicle efficiency as calculation factors, the cart will require approximately 2 kWh

each day.

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6.1.3 Available Energy: Local Solar Insolation

Solar energy is more practical in some areas of the world than others. The solar

insolation value is a way to compare the equivalent power radiated on each portion of the earths

surface. Jamaica receives an equivalent average of five hours of full power sunlight each day.

Figure 18: Solar insolation for the Caribbean15

6.1.4 Anticipated System Efficiencies

The design of this storage system requires

monitored charging and discharging of a battery

bank as well as conversion of the current from DC

to AC with the use of an inverter. The addition of

each step in this process also results in additional inefficiencies of the system. The table in figure

19 shows the anticipated losses for each component. These efficiencies can be multiplied together

to get the total system efficiency. The system will deliver an estimated 50% of the energy

generated by the solar panels. Although this charge shuffling results in a great loss, the

versatility of the design makes this an essential and unavoidable cost.

Figure 19: Estimated Efficiencies

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6.1.5 System Load Sizing Calculations

Solar power systems are sized by

required loads. Compiling the information of

the total distance the vehicles travel in a day, the

efficiencies of the vehicle and of the charging

process, and the power available in Jamaica, the

required watt produced in the day can be

determined. The approximate power demand is

660 W. These calculations are shown in figure 20.

6.2 Available Charge Sources6.2.1 Meeting the Power Needs with Photovoltaics

The original intentions of the project were to power the entire charger with photovoltaic

panels, however, these are expensive. The required panels would cost approximately $4,000.

Due to the budget limitations of the project, the cost of purchasing new panels to meet the power

requirements would be much greater than the funds available. When the Center for

Sustainability at Penn State was informed of the need of solar panels for the Jacobs Ladder

project, they responded by donating six

Solarex MST43-MV panels. These

panels had previously provided power

for the solar pump house at the

Renewable Energy Homestead. The

Homestead has fallen into disrepair, and

is slated for demolition before the Spring

of 2009.

Figure 20: System Sizing Calculations

Figure 21: MST43-MV panels at the PSU CFS site.

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The panels are a thin-film design manufactured in 1999. A weakness of the panels is a

high inefficiency; each panel is rated at 43.0 W.16 The six panels available from the Center for

Sustainability total 260 W. Using the solar insolation value for Jamaica, the panels would

produce approximately .65 kWh on a sunny day. This leaves 1.35 kWh to be produced by

alternative means. The remaining panels needed to produce this remaining power could be

purchased at approximately $1000 for a 200W panel.

6.2.2 Available Wind Energy Production Resources

In addition to the solar panels

available at the Penn State Renewable Energy

Homestead, a small wind turbine has also been

decommissioned. Another option to provide

power for the charging station would be to use

a hybrid system including both solar and wind

energy sources. Wind turbines are cost

effective. The Southwest Air X turbine is priced

at approximately $600, and can provide 400 W.17

6.2.3 Advantages and Disadvantages of Hybrid Power Systems

A hybrid charging system is able to

take advantage of the benefits of both the solar

and wind. Hybrid wind and solar energy

production methods work together to supply a

more constant power source than either system

would do in a stand alone format. In many

areas, wind speeds vary seasonally. In much of

Figure 22: Air X Turbine at CFS Site

Figure 23: Hybrid Power System

-22-

the United States, wind speeds are low in the summer when the sun shines brightest and longest.

The wind is strong in the winter when less sunlight is available.18 This arrangement produces a

smooth power source, and can be installed with little extra equipment or effort. The

diversification of power sources is a key advantage of hybrid arrangement.

6.2.4 Mustard Seed Wind Development Plans

Mustard Seed Communities is hoping to expand their renewable energy portfolio to

include power generated from biofuels, waste methane, and wind energy. Small wind turbines

are simple, relatively efficient, require little maintenance, and provide an exciting visual

appearance of sustainable energy sources.2

6.2.5 Wind Availability at Jacobs Ladder

Preliminary wind data provided by AWS Truewind for the site shows little promise at

successfully placing a wind turbine on the site. This data can be found in Appendix D. In a

statement accompanying the data, however, AWS states: the proprietary data is an estimate, and

an on-site Met station must be established to confirm the potential of the region.19 Although no

anemometer has been placed on site, two site visits confirmed a steady breeze blowing out of the

mountains in the Northeast, and peaking in velocity near the crest of the main hill at the center of

the site. If any area of the site has the wind potential necessary to generate power, it would be the

location planned for the station. Regardless of the preliminary wind data, Mustard Seed is

planning to develop wind turbines on the site anyway to provide a visual of sustainability.2

6.3 Station Location Concepts: Finding the Optimum Placement6.3.1 Option 1: Site Entrance

Visitors and Staff entering Jacobs Ladder must first pass through a gated front driveway.

Although some areas of the facility are fenced to keep residents from danger, the front gate is a

traditional feature of most Jamaican businesses, public areas, and complexes. The charger could

be positioned South of a grove of trees the left side of the path leading from the site entrance.

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This position would provide optimum accessibility for staff, using the carts for transportation

into the site. As homes continue to be constructed stretching deeper into the site, this location

will not be central to the operations.

Figure 24: Proposed Site Entrance Location 6.3.2 Chapel

Faith is at the center of the mission of Mustard Seed Communities, and the chapel is

located near the proposed center of the site. This location would be an easily accessible location

for a charger. Visitors to the site, and investors interested in the development of sustainable

technologies at Jacobs Ladder will pass through this location. The chapel also serves as a

valuable central hub for transportation and the movement of people throughout the site, forming

a bridge to the rest of the currently undeveloped site.

-24-

Figure 25: Proposed Chapel Location6.3.3 Demonstration Village

Penn State has begun concentrated design work on a 10-15 acre plot of the entire 100 acre

site. This land will serve as a demonstration village to showcase the sustainable and renewable

agriculture methods Penn State is working to develop on the site.5 Locating the charging station

here would group all of the Penn State contributions in one area, and would become a more

centralized facility as the site continues development.

Figure 26: Proposed Demonstration Village Location

6.4 Station Location Selection

After completing the AHP matrix for the station location, the most important design

criteria were determined to be the educational value of the location, and the ability of the location

to benefit future development of the site. The results of the concept selection matrix showed that

the chapel location provided the greatest benefit for educational potential, locating the charger at

the center of the site, and at the gateway to the Penn State Demonstration Village. The AHP and

concept selection matrices can be found in Appendix H.

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6.5 Station Configuration Concepts: A Functional Design6.5.1 Mounted on Existing Building

The hill at the center of the site is

occupied by two structures: the chapel, and

the administration building. These buildings,

originally constructed for the Jamaican

wharves, were transported to Jacobs Ladder

after they were decommissioned from

service. The buildings have large galvanized

steel roofs, and are adequately oriented to optimize solar panel efficiency. Panels mounted in this

location would be visible, but would not have an obvious link to the load driven by the charger.

6.5.2 Mounted on Proposed Library

The first Penn State project to be

installed at Jacobs Ladder is a sustainable

library constructed from a recycled shipping

container. This library will serve as the

gateway to the demonstration village, and

contain resources for the Mustard Seed staff

to maintain and learn about the technologies on

site. This scenario groups the charger with other Penn State projects, and keeps the solar panels

from being shaded or damaged.

Figure 27: Existing Chapel

Figure 28: Container Library Mount

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6.5.3 Ground Mount

Perhaps the most simple option for

solar panel mounting is a ground rack. The

ground mount provides a low profile, a

reduced wind load for hurricanes, and is a

stand-alone system. The ground mount also

has an associated risk: the panels could easily

be blocked by vehicles, growing vegetation or

even buildings constructed after the installation of the panels. The power output of shaded

panels is dramatically reduced. Panels on the ground also are at a higher risk of being damaged.

6.6 Station Configuration Selection

After evaluating the criteria for the station configuration, it was determined that

educational value, safety, and durability of the design were the most important factors

influencing the design choice. The library mounting scenario was chosen. This design places the

panels at a facility that is meant to be the center for educational information regarding

sustainability, and gets the panels off of the ground where they could be blocked, or damaged.

The AHP and concept selection matrices can be found in Appendix I.

7. Detailed Design

The charging station is made up of three basic components: the charge source, processing

electronics, and the charger - user interface. This section is an exploration of each of these

systems, and the decisions and procedures used to arrive at the final design.

Figure 29: Ground Mounted

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7.1 Station Design: The Charge Sources7.1.1 Solar Array

The Penn State University Center for Sustainability donated six

Solarex MST43-MV thin film solar panels. The panels had previously

been utilized in a solar water pumping station at the Renewable Energy

Homestead. Although the panels are designed for use in moderate to

high voltage arrays, the panels were previously utilized with a 12 VDC

battery bank. As much of the system had already been salvaged, no other electronics could be

utilized from the Homestead.

An important tool to understand the operating characteristics of a solar panel is the

current voltage curve (I-V curve) as designated by the manufacturer. The curve is used to

determine the maximum current and voltage of the

panel.8 Figure 30 shows the I-V curve for the MST43-MV.

The two curves shown in the figure represent different

light test illuminations: the upper curve is tested at 1

kW/m2 and the lower is tested at 250 W/m2. Electrical

power is the product of current and voltage, therefore

the maximum power point of the panel is at the knee of

the curve. The I-V curve confirms the panel

specifications that claim a maximum power point of 43

W when the voltage is 72 VDC, and the current is 0.6 A.16

7.1.2 Solar Integrated Green Roof

The Jacobs Ladder Library design is a twenty foot long by eight foot wide shipping

container. Recycled shipping containers are widely used across Jamaica for houses and shops.

Jamaica receives the majority of their goods in a constant stream of container ships, creating an

Figure 30: MST43-MV I-V Curve

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available supply of shipping containers. The metal box provides a weather-tight, sturdy shell for

a wide variety of needs.

One weakness of shipping containers is a lack of insulation. Especially in tropical

climates like Jamaica, containers are prone to overheating if placed in direct sunlight. One

advantage of the solar integrated green

roof design is provide a form of

insulation for the roof. Growing plants

on a roof requires approximately four

inches of soil, but builds thermal mass on

the roof, moderating the temperature of

the living space below. The solar array

will also shade the majority of the

container roof, and will be elevated

slightly to allow air flow to whisk excess

heat from the roof.20

7.1.3 Solar Array Mounting Configuration

A green roof is an effective insulator, but also adds a large amount of weight to the roof.

To support the combined weight of the green roof and solar array, a frame has been designed to

transmit the weight to the four corner support posts of the container. Loaded containers are

normally stacked on ships up to eight containers high. The added roof weight is insignificant if

carried by these supports. To accomplish this, a frame has been designed from 2 x 6 boards to

sit on the side rails of the container. The frame serves to contain the support the green roof, and

to provide a mounting location for the solar array. The solar array will be mounted on a wooden

Figure 31: Solar Array and Green Roof

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frame constructed from 2 x 4 boards. The frame is angled at eighteen degrees from horizontal,

equal to the latitude for the site.20

Figure 31: Solar Array Roof Mount Assembly

The six Solarex MST-43MV panels are affixed to the mount with two angle iron rail pieces

on the top and bottom of the panel. Neighboring panels are bolted together, and the entire

assembly is secured to the roof rack with lag bolts. The mount for solar panels must be safe and

secure, especially in Caribbean, hurricane-prone locations. To ensure that the solar roof rack

would survive the high winds of the hurricane, the structure was was designed with similar or

stronger materials and techniques than the buildings already on site. All connections on the roof

rack are also to be made with screws instead of nails. Screws hold stronger in the wood, and rip

out less frequently in a hurricane.21

Figure 32: Solar Panel Attachment Design

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7.1.4 Wind Turbine

The Air X wind turbine is rated for 12 VDC output. The rotor

diameter is small, only 46 inches, yet the turbine is capable of

generating 400 W with a 28 mph wind. A unique feature of the turbine

is the speed control

function. The turbine is controlled by a

microprocessor, allowing the turbine to be

connected directly to a battery bank. The turbine

will reduce rotation speed if the wind speed is to

high, or if the battery is charged.17

7.1.5 Wind Turbine Placement

The chapel location is ideal for

the placement of the wind turbine. The

area is the highest location on the site, and

a steady wind blows from the North. The

wind speed and direction data for the

Mustard Seed site are located in Appendix

D. The turbine must be located near the

charging station to reduce the losses of the

generated DC power.17 Regardless of

engineering requirements for power loss,

the turbine should be located close to the

container library to promote the vision of

a unified power system for the building.

Figure 33: Monthly Output of Air X TurbineH

Chapel

Admin

Figure 34: Red Dot Shows Proposed Location of Wind Turbine on North Side of

Wind Direction

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The wind turbine may face power losses due to the proximity of the turbine to the

chapel. Although the structure is currently open-air, Mustard Seed plans to enclose the sides as

the development of the site continues. The primary wind direction is not impeded by the

structure, but turbulence from the building may reduce the power generated. Another option for

the mount of the turbine was to attach the support poles to the main beams of the chapel. This

mounting scenario was discarded due to concerns of vibration, noise, and the difficulty to repair

and access the turbine in the case of a hurricane. A ground mounted turbine can quickly be

disassembled, and will not face as the same strength winds as a turbine mounted high on an

existing building.

To provide rigidity yet ease of disassembly, the

turbine will be mounted on a twenty foot long piece of

metal schedule 40 pipe, and affixed to the ground with

three guy wires. The guy wires are attached to the

cement piers surrounding the pole. All areas of cement

will need to be reinforced with rebar.

7.1.5 Electrical Connectivity

To protect the wires from the elements, all cabling will be

strung through electrical conduit. The plastic enclosure on conduit

keeps the wire from deteriorating in the sunlight, and also helps to keep

the wiring organized.

Figure 35: Sketch of Guy Wires

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7.2 Station Design: Processing Electronics7.2.1 DC Breaker Box

The original breaker box from the Renewable Energy

Homestead at Penn State was salvaged to be reused for the solar array.

The box is manufactured by Outback, and was originally intended to

pair with the PS1 power system and Outback charge controller. The

breaker box is the location for all electrical connection in the system. The

front panel contains circuit breakers which enable the batteries, and panels to be disconnected.

The wiring for the solar array and the wind turbine will be combined in the breaker box. Every

device in the charging station is routed through the breaker box.

7.2.2 Wire Sizing Calculations

The sizing of electrical wire in any power system is important because the gauge of the

wire determines the total current that can safely flow through wire. Decreasing the wire diameter

increases the resistance of the current

through the wire. As resistance increases,

the wire is in danger of overheating, with the

potential of starting electrical fires. To avoid

possible hazards, wire gauge has been

standardized by the American Wire Gauge

(AWG).8 Figure 36 shows the relative wire

cross sections of several different wire gauges.

Figure 36: AWG Sizing Scale8

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7.2.3 Charge Controller

The charge controller used for the charging station is the

Outback MX-60. A solar array typically operates at 12 - 24 VDC, and

therefore most charge controllers operate at this range. The Solarex

MST43-MV panels operate at a moderate voltage range of 72 VDC

nominal. Few commercially available charge controllers can actually accept a voltage this high.

The MX-60 was primarily chosen for the wide voltage range of input and outputs; accepting any

PV array voltage up to 72 VDC, and 12, 24, 36,48,

and 60 VDC battery banks. The voltage step down

from the 72 VDC array to a 12 VDC battery bank is

made possible by the digital Maximum Power

Point Tracking (MPPT) circuitry. This function

searches the array to determine the maximum

power point voltage, and proceeds to charge the

batteries at this point.22 The MST43-MV I-V curve

in Figure 37 has been annotated to describe the

effect of MPPT on the power output of the

system. Without the step-down abilities of the MX-60, the charge controller could only charge the

batteries at the voltage of the battery bank, here 12 V. The location of 12 V is designated on the I-

V curve by the letter A. The maximum power point is marked by the letter B. The power output

at A can be calculated by multiplying 12 V by approximately 0.78 A current, resulting in an

output of 9.36 W compared to the rated output of the panels at 43 W, an 80 percent power loss in

the output of the panels.8

AB

Figure 37: Effects of MPPTI

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In other areas, the Outback MX-60 is more of a powerful and sophisticated device than

the charging station would require. It can handle up to 60 A of input current, where the solar

array will likely output no more than 3.6 A. The unit also has many features that are beneficial

for educational demonstration. The MX-60 logs and saves 64 days of operational data that can be

reviewed. These data can be used to compare the output of the power generation sources with

weather conditions, and be used to log the energy production of the entire system.22

7.2.4 Battery Bank

The battery bank was donated to the project by the Penn State

Solar Decathlon team. The four UB12900 batteries had been purchased

as a replacement batteries for a set used in the 2007 Solar Decathlon

competition. The batteries operate at 12 VDC nominal, are each 90 Amp

hours, totaling 360 Amp hours of storage. The four batteries will be wired in parallel. In this

configuration, the current will add and the voltage will remain constant.8

To maximize the life of the battery, the bank should be designed to operate in the

required range without discharging below 50% of the total storage capacity. This battery bank

then has 180 Amp hours of storage. A simple conversion can be used to convert the total Amp

hours to the number of kilowatt hours stored in the batteries. Since power is the product of

current and voltage, a kilowatt hour is equal to the Amp hour storage of the battery bank

multiplied by the voltage of the battery bank, and divided by 1000. Here, the total kilowatt hours

stored by the four UB12900 batteries is 2.16 kWh. The approximate required demand for the golf

carts is 2 kWh. As anticipated, the storage in the battery bank is larger than a single day of

operation. Ideally, the battery bank would be large enough to allow for more than one day of

storage. The relatively high cost of batteries, and the tight budget demands on this project did

not allow additional batteries to be purchased to expand the bank, although the bank can be

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expanded at any point. Also, because the batteries are wired in parallel, additional batteries can

be added at any time.

7.2.5 Inverter

Inverters are separated into two primary categories: those that

produce a modified sine wave, and those that generate a pure sine

wave. The difference is in the quality of the power, and the price of the

inverter. The voltage provided by a modified sine wave inverter does

not follow the same smooth oscillation as a pure sine wave generator as shown in Figure 38.

Figure 38: Comparison of Modified Sine Wave and Pure Sine PowerJ

The consequence of using a modified sine wave instead of a pure sine wave is

diminished performance from electrical equipment using the output power of the inverter. The

efficiency of motors and transformers will be reduced, and more sensitive electronics will

experience uncharacteristic performance problems. Problems such as crackling in audio

equipment or rolling lines on digital display screens are common results of diminished power

quality.24

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In this case, the modified sine wave inverter may cause decreased performance for the

charger. When designing a system for the lowest possible cost, it can be difficult to determine

where to sacrifice quality for price. In this instance, where the donated solar panels and wind

turbine prevent the quantity of available charge from being the most serious concern, a modified

sine wave inverter was chosen.

The Go-Power GP-1750HD inverter is capable of continuously producing 1500 W of

output power. The side view of the inverter in figure 39 shows the output and status indicators

on the GP-1750HD inverter.25 The bar graph meters, over temp and overload indicators are

valuable status indicators to help diagnose possible problems with the inverter. The most

significant feature of the inverter for a small scale charging station with few loads is the pair of

AC outlets. These outlets allow the charger to simply plug into the inverter.

Figure 39 : Side Panel View of Inverter Showing Indicators and ConnectionsK

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7.3 Station Design: The Charger - User Interface7.3.1 Benefits of an AC Receptacle

The charger has been designed and sized specifically for a single golf cart charging unit.

Although this is the intended use of the power, the needs of the site will likely change, and the

charging station should be designed to be flexible. The output of the charging station is an AC

receptacle, allowing the users to plug any 110 VAC device. A light, radio, or fan could be plugged

into this receptacle with little consequence to the total available power.

7.3.2 Golf Cart Charger

The golf cart is charged with a mobile charging unit. Currently,

the Jacobs Ladder site operators keep the charger on the golf cart at all

times in a small compartment beneath the rear seat. The charger is

plugged into the golf cart, and has a standard US three-prong plug to

connect to a 110 VAC source. When the golf carts pull up to the library container, the plug can be

inserted into the 110 VAC receptacle for the duration of the charge. After an unfortunate string of

days with little wind or sun, when the station is depleted of charge, the cart can dock instead at

another receptacle.

7.4 Station Overall System Design 7.4.1 Charging Unit Placement

All charger components must be grouped in the container library to maximize their

functionality, accessibility, and educational potential. The design for the charger must also

complement the intended purpose of the library. To accomplish this, an overall design for the

container was created. The design specifies a corner of the container to hold all of the solar

components in a centralized and concentrated location.

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Figure 40: Container Floor PlanC

In this arrangement, visitors will be able to view the solar electrical components

immediately upon entering the door of the container. This location has been chosen to reduce the

risk of water damage to the electrical components. All equipment is wall mounted above the

level of the air vents. This placement of the electrical components will unify the entire North half

of the container as an informational area for sustainable development of the site.

7.4.2 Electrical Component Arrangement

The electrical components are all to be mounted on a sheet of 1/2 thick plywood. The

components are arranged to provide a logical flow of electrical current through the equipment.

Figure 41 shows the mounting location of the system components.

A B

D

C

EFigure 41: Component Arrangement

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Wires from the solar array will first enter the disconnect box (A), then enter the Outback

breaker box. The breaker box forms the central network for the remaining components; both the

charge controller and inverter are wired onto respective terminals of the breaker box. The final

disconnect box is used to separate the batteries from the breaker box. The full circuit diagram of

the breaker box, is found in Appendix O.

7.4.3 Solar Charging Station Rack Mount

The charging station rack mount has been

designed to hold and protect the solar components, place

the components in an educational arrangement, and

interface smoothly with the library bookshelves.

In this arrangement, all components are

protected, yet visible for viewing. The batteries will be

placed off the ground on an extended bookshelf, and will

be covered by plexiglass. Although batteries are not

particularly dangerous, they should be kept out of reach.

The rear 2x4 support posts will be bolted to the

Western wall of the container. Upon completion of the

container library, bookshelves will interface with the

edges of the charging station rack mount to form a

unified transition between library and electrical

container spaces. Figure 42: Component Mounting Scenario

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7.5 Project Budget and Cost Analysis

The project was sponsored by In total, the charging station components could all be

acquired for approximately $1100. Detailed budget information can be found in Appendix P. An

additional $750 was spent to ship the components to Jamaica.

8. Implementation: Jamaica Design-Build8.1 Overview of Design Build Week

Over the Thanksgiving week of 2008, the Penn State Jacobs Ladder Design-Build team

traveled to Jamaica to construct the shipping container library and the solar wind hybrid

charging station. A total of five University students were led by Dr. Neil Brown. The team had

planned a four day intensive build to complete the projects. The team had coordinated the

delivery of the container and the shipping of the solar components to arrive on site before the

team arrived on November 22, 2008.

8.2 Murphys Law8.2.1 Weather

November is rainy season in Jamaica. Daily periods of rain wash over the Blue

Mountains. The MSC staff working in Jamaica intended to build a concrete foundation for the

container before the team arrived, however, due to the periodic rain, this foundation could not be

poured. Instead, a temporary foundation was

constructed from cement blocks.

Concerns over the strength of the blocks led

to caution during the build week. Similar concrete

blocks on site crumbled when used as a stepping

stool, or even when moved. As a result, massive

building components were not assembled such as the green roof and solar mounting rack

Figure 43: Temporary Block Foundation

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8.2.2 Where are the Solar Components?

To reduce the budget, every attempt was made to acquire donated project materials in

the United States. Costs were reduced dramatically by utilizing the solar panels and the wind

turbine donated by the Penn State Center for Sustainability. In this way, the high cost of new

materials led to the hybrid power system, a better design for the site.

Though not particularly sustainable, or beneficial for the local economy of Jamaica, plans

were made to ship many of the donated materials to the site. These plans were formulated after

learning that MSC has free international shipping with Food For the Poor, a faith-based non profit

organization. MSC representatives reported to the Penn State Jacobs Ladder development team

that a shipment could be sent to Jamaica in the period of two weeks, and arrive on site.2 Little

more than a month before the implementation week, the team was informed by MSC staff that

the two week quote had been a mistake; rather, a two week notification was needed to get the

materials picked up. Shipping required another two months. Another shipping option was

necessary.

Next, the Jacobs Ladder team contracted with an independent shipping company,

promising arrival of the solar components over a week before the team was schedule to arrive in

Jamaica. The components were packed, and the shipment was made. The day before departure

for Jamaica, the team learned that the shipment of the components had been delayed, and the

new estimated arrival date was after the implementation week.

8.3 Revised Plans8.3.1 Theory of Appropriate Technology

The absence of solar components brought a new set of questions. Should the installation

be pushed off until the next trip to Jamaica? Will future Penn State design teams know how to

install the solar power system? Could the charging station be constructed and maintained by

local Jamaicans without help of Penn State?

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The final question set a new standard for the continuation of the project that shouldve

been with the project from the beginning. Appropriate technology utilizes environmentally,

economically, and socially sustainable solutions for communities to reduce poverty and protect

natural resources.26 When implementing a new technology, can a build-and-run installation ever

be successful? Although the charging station encompassed many aspects of sustainability, it

lacked the self-sustaining component that frequently makes similar projects fail. A technology is

not a solution if individuals on the ground cannot understand enough to keep it working.

8.3.2 Installation and Instruction Manual

The charger is not particularly complicated, but if the designer hundreds of miles away is

the only person who understands the functionality of the entire system, even the smallest glitch

could derail successful operation. In an attempt to make the design comprehendible and within

technological reach of the local staff workers, an installation manual will be developed to

describe the system components, how they are assembled, and cared for. The installation manual

will begin as a specific instructional document for installing this specific solar charger design, but

over time will develop into a more general installation manual to train and prepare electrical

installers for solar work.

8.3.3 Developing Local Connections

To test the appropriateness of the solar installation manual, and the appropriateness of

the design, Jamaican University students will assemble the charging station with the installation

manual. Local technical connections are needed to guarantee the successful future operation of

the charging station, and to build sustainable international relationships for future developmental

work at Jacobs Ladder. In past projects, The Engineering Design School at Penn State has

partnered with the University of Technology (UTech) in Kingston, Jamaica. UTech is again

interested to partner with the installation of the solar components. A masters student with an

interest in solar power for water pumping applications will be starting at UTech in the Spring of

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2009. This student will work with the Penn State Jacobs Ladder design team to install the power

system.

8.3.4 Future Alternative Energy Conference

The design team is hoping to expand on the partnership formed from the solar

installation into an international forum on alternative energy. One of the goals of MSC is to give

back to the neighboring communities struggling to solve daily problems. Upon installation of the

solar charger, The Penn State University will plan a weekend long alternative energy conference

at the MSC Jacobs Ladder site. The numerous alternative energy technology companies in

Jamaica will be invited to share products and expertise. Jamaican University professors, students

and interested community members will be invited to learn about alternative energy and

sustainability. The conference will close by re-assembling portions of the hybrid charger to give

conference attendees hands on experience with solar and wind systems.

8.4 Results of Design-Build Week8.4.1 Placement and Finishing of Container Library

Despite the unfortunate weather conditions, and lack of solar components, a large

amount of work still was completed on the

container library. Holes were cut in the

container wall to form spaces for air vents,

windows and doors. After completion of the

chapel, the container library and sensory garden

will be a welcoming place for residents to pause

and relax. Figure 44: South Container Elevation

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Figure 45: View of Container looking Westward toward Chapel

8.4.2 Completed Library Interior

The interior of the library was converted from a empty shipping container into library

with bookshelves surrounding the perimeter of the building. Figure 46 is a view from the open

doors of the container. The photo on the left is an actual image of the container taken at the end

of the build week. The photo on the right is an image of the container with digitally

superimposed solar components, books, and display posters.

Figure 46: Developed Container Library

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8.4.3 Identification of Electrical Vehicle Specifications

Sizing calculations for the charger specifications were completed before the electric

vehicles arrived at the Jacobs Ladder site. Two golf carts were acquired by MSC, however, only

one is currently operational. The cart is an EZ-GO TXT Shuttle. On this trip, the cart usage could

be observed for the first time. The primary user of the cart was the site operator, Brother

Anthony on many quick trips about the site; although he was suffering from an injured foot and

had difficulty walking.

9. Conclusions9.1 Experiences and Lessons Learned

The difficulty planning for and organizing the build week in Jamaica revealed many

realities of international work. It is difficult. Proper preparation and planning does not

guarantee a successful implementation. When weather, language, and cultural differences clash,

plans change, and project goals are redefined. The shipping problems changed the scope of the

project, and as a result, the entire design became more sustainable. International relationships are

being developed that would not have otherwise. The project revealed that problems can be an

opportunity to improve a design.

9.2 Improvements: A Marketable Design9.2.1 A Justification for Alternatives: The Cost of Power

Though alternative power systems may seem complex and expensive, It is important to

remember that power is not free, especially in areas of developing nations far removed from an

electrical provider. During the first community assessment trip to the Mustard Seed site in

January of 2008, the Jamaican Public Service (JPS) was working to erect 13 concrete power

transmission poles to carry electricity to the Jacobs Ladder site. Although Mustard Seed as a

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non-profit organization did not pay for

the transmission lines, they are quite

costly. When long power-line runs are

brought into consideration, off-grid

power systems may become the only

option.

Electricity in many developing

countries is largely a temporary notion.

Variable rates and intermittent service keep the grid from being a reliable power source, even if a

community is lucky enough to have a power transmission line stretching to their homes.

9.2.2 An Analysis of the Project Costs The implementation of any solar power system is a significant investment, in this case,

significantly more than the available grants. Fortunately for the success of the project, the Center

for Sustainability at Penn State was able to provide a large amount of the equipment. Without

these donations, the cost of the charge sources (solar panels and wind turbine) would have been

beyond the available project budget. Despite the financial advantage, the solar panels carried a

set of disadvantages. The panels operated at a low efficiency, a high voltage, required a large

mounting space, and a sophisticated charge controller to make the charge usable. Had all of the

components been purchased, a unified design would have greatly streamlined the charger, and

decreased the cost and sophistication of components.

Figure 47: Power Lines Stretching to MSC Site

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9.2.3 The Redesign

In an attempt to determine the actual cost of the charger without donations and

unusually group parts, the charger has been redesigned with new, commercially available parts.

This charger has an identical power output with the Library Charger.

Southwest Wind Power Air X 12 V Turbine

The Southwest wind turbine is the same design as the turbine used in the

charging station. The turbine is microprocessor controlled, and does not require a charge

controller.17

Kyocera KC130TM 130 W

The Kyocera polycrystalline panel operates at 12 VDC, and outputs a current of

7.39 A, producing a total power rating of 130 W. Two of these panels produce the same power as

the six Solarex thin-film panels used in the charging station.27

Morningstar Prostar 15A, 12V Charge Controller

The charge controller is the most significant change from the original design.

The Morningstar Sunsaver is simple, but complete in operational functionality. The primary

disadvantage of the Sunsaver compared to more expensive charge controllers is the lack of

Maximum Power Point Tracking capabilities, therefore the system will loose efficiency as the

solar intensity changes throughout the day.28

Go Power GP-1750HD Inverter

The Go Power inverter is the same model as implemented in the charing station

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design. The inverter is low cost and delivers dual 110 VAC outlet for plug loads, making

transitions quick and easy.25

UB12900 Sealed 12 V AGM Battery 90 Ah

The redesign utilizes the same battery bank, providing 360 Ah of storage. The

batteries are connected in parallel. The bank could be expanded by adding an additional battery

if additional storage is desired.23

Midnite Solar MNPV6 Combiner Box

The combiner box is the central linking unit for all electrical components. The

combiner box contains the busbars and fuses for electrical interconnections.29

Square D Disconnects

Electrical disconnects are needed to cut electrical power to components during

system maintenance. The Square D disconnect utilizes 100 A fuses to protect electrical inputs.30

Figure 48: Charging Station Redesign - Component Cost Estimation

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As expected, the cost of the components is far greater than the project budget, however,

when shipping costs are added, the figures become much closer. The system cost is certainly

reasonable for a small scale power system.

9.3 Feasibility of Implementing Design in Developing Nations

The design is feasible for developing countries, especially if the solar energy systems are

sold as kits, manufacturers use interchangeable parts, and knowledgeable technicians exist to

answer questions and repair broken systems. A benefit of solar power is that there are no moving

parts, creating systems requiring very low maintenance. The cost of solar power systems is

significant, however, in many cases this cost may be the only option for power.

9.4 Personal Impact of Development Work

After completing a full degree of credits at Penn State, the most meaningful learning

experiences have happened outside of the classroom. I believe that an international education is

one of the most important prerequisites for life after college. Whether working internationally or

at home, past experiences abroad are valuable in shaping a global worldview. My work with

Mustard Seed Communities and their Jacobs Ladder community has been my longest extended

international experience, with three trips and counting. Each time I leave Jamaica, I have the

knowledge that I will be back before long. This project has helped me to understand the

importance of sustainability. I am now beginning to grasp the importance of all aspects of a

sustainable design: how does it benefit the people, their financial well-being, and the health of

their environment.

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10. Acknowledgments

This project never would have been completed without the patience, sacrifice, and

assistance of many professors, friends, and family. To Dr. Colledge, thank you for opening the

door to international development and appropriate technology. Thank you Dr. Lau for teaching

me about sustainability. To Dr. Riley and the Penn State Center for Sustainability, thank you for

donating a wealth of system components. To the Carter Academic Service Entrepreneur (CASE)

Grant Selection Committee, the Alliance for Earth Sciences, Engineering, and Development in

Africa (AESEDA), and the Schreyer Honors College, thank you for providing the funding to

make this project possible. To Vaughn, Mclean, and Grim, thank you for sacrificing your

Thanksgiving break to work from dawn to dusk in Jamaica. To Dr. Neil Brown for the mentoring

and friendship. Thank you for placing trust, hope, and confidence in idealistic undergraduates.

To my family, thank you for sending me to Penn State, and encouraging my educational

development. To Spud, I think were still on track to save the world. Finally, to Ruth, thank you

for your endless love and encouragement. I love you, and cannot wait till I can call you my wife.

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Appendix

Appendix A: References 2Appendix B: Image Credits 5Appendix C : Community Assessment: Site Maps 6Appendix D: Wind Data 7Appendix E: Needs Assessment Evaluation 8Appendix F: Quality Function Deployment (QFD) Matrix 11Appendix G: Charge Storage Selection Matrices 12

G.1 Analytical Hierarchy Process Matrix 12G.2 Concept Selection Matrix 12

Appendix H: Site Location Selection Matrices 13H.1 Analytical Hierarchy Process Matrix 13H.2 Concept Selection Matrix 13

Appendix I: Station Design Selection Matrices 14I.1 Analytical Hierarchy Process Matrix 14I.2 Concept Selection Matrix 14

Appendix J: Dimensioned Library Drawings 15Appendix K: Dimensioned Solar Mounting Rack 16Appendix L: Wind Turbine Mounting Design 17Appendix M: Dimensioned Solar Charger Drawings 18Appendix N: Wind Turbine Hybrid Wiring Scheme 19Appendix O: Breaker Box Wiring Schematic 20Appendix P: Detailed Budget and Cost Analysis 21

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Appendix A: References

1. "Mission Statement." 2007. Mustard Seed Communities. Nov. 2007 .

2. Moran, Matthew. "Jacob's Ladder Planning Sessions." Telephone interview with Steven F.

Marshall and Eric M. Sauder. Dec. 2008.

3. Ramkissoon, Gregory. Interview with Eric M. Sauder, Steven F. Marshall and Neil E. Brown.

Mar. 2008.

4. Ramkissoon, Clyde. Interview with Eric M. Sauder and Neil E. Borwn. Mar. 2008.

5.Brown, Neil E., Steven F. Marshall, and Eric M. Sauder. "The Plan for Jacobs Ladder." Jacob's

Ladder: A Sustainable Community for Disabled Individuals of Jamaica. Vol. 1. Oct. 2008.

2-3.

6. "Mining." The Gleaner. 4 Dec. 2008

7. Brother Anthony. Interview with Eric M. Sauder, Steven F. Marshall and Neil E Brown. Mar.

2008.

8. Dunlop, Jim. Photovoltaic Systems. Ed. Todd W. Stafford. Homewood, Illinois: American

Technical, Inc., 2007.

9. "Nanosolar to build world's largest solar cell factory." 21 June 2006. Nanosolar. 4 Dec. 2008

.

10. "Latitude and Longitude: USA." BCCA. 22 Nov. 2008 .

11. Baxter, Richard. Energy Storage : A Nontechnical Guide. New York: PennWell Corporation,

2005.

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12. Sunray Solar Roof Kit. Electric Transportation of Arkansas. 2007. 18 August 2008.

13. Solar Roof Kit. Cruise Car. 2007. 18 August 2008.

14. Transportation Analysis for the Solar Decathalon Competition. Tech.No. Solar Decathalon

Team, Colorado University. 2-4.

15. Mexico and Central America Solar Insolation Map. Alternative Energy Store. 7 Sept. 2008

.

16. Photovoltaic Modules: MST-43MV. Solarex, 1999.

17. Air X Owners Manual. Southwest Windpower, Inc. 9 October 2002.

18. Small "Hybrid" Solar and Wind Electric Systems. 12 Sept. 2005. Energy Efficiency and

Renewable Energy. 5 Oct. 2008 .

19. "AWS Truewind Wind Resources." Email to Matthew Moran.

20. Marshall, Steven F. "Sustainable Design and Construction of a Library for Disabled Children

of Jamaica." Thesis.

21. The Definitive Guide to Hurricane Protection." 4 Oct. 2007. Hurricane Protection Guidance. 2

Dec. 2008 .

22. MX60 PV MPPT Charge Controller: Installation, Programming and Users Manual. Outback

Power Systems. 29 January 2007.

23. UB12900 Specifications Sheet. Universal Battery, 2008.

-3-

24. DC - AC Converter Sizing Considerations. 2007. BD Batteries. 2 Dec. 2008 .

25. GO Power! Modified Sine Wave Inverter Owners Manual. Go Power! Electric Inc.

26. The National Center for Appropriate Technology. 2008. NCAT. 6 Dec. 2008 .

27. Kyocera KC130TM Specifications Sheet. Kyocera, 2008.

28. Morningstar Prostar Specifications Sheet. Morningstar Corporation, 2008.

29. Midnite Solar MNPV6 Installation Instructions. Midnite Solar, 2007.

30. Enclosed Safety Switches. Square D, 1999.

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Appendix B: Image Credits

A. MSC Logo. Digital Image. 2007. Mustard Seed Communities. 7 Dec. 2008 .

B. Jamaica Satellite. Digital Image. 2008. Google. 5 Dec. 2008 < http://www.maps.google.com>.

C. Penn State Jacobs Ladder Development Team. 2008.

D. "Solar Electric." 2008. Real Goods. 2 Dec. 2008 .

E. Solar Window. Digital Image. Lighting. OK Solar. 5 Dec. 2008 .

F. Ultra Capacitors. Digital Image. 2008. Tree Hugger. 15 Nov. 2008 < http://i.treehugger.com/

files/DDE-eichenberg-f2.jpg>.

G. Small "Hybrid" Solar and Wind Electric Systems. Digital Image. 12 Sept. 2005. Energy

Efficiency and Renewable Energy. 5 Oct. 2008 .

H. Air X Turbine. Digital Image. 2007. Southwest Windpower.

I. Photovoltaic Modules: MST-43MV. Digital Image. Solarex, 1999.

J. DC - AC Converter Sizing Considerations. 2007. Digital image. BD Batteries. 2 Dec. 2008

.

K. GO Power! Modified Sine Wave Inverter Owners Manual. Digital image. Go Power! Electric

Inc.

L. Haddon Hall, Saint Ann. Digital Survey Image. 2003. J.R. Mais & Associates Ltd.

M. Mustard Seed - Jacobs Ladder Development Mean Annual Wind Speed at 30 Meters AWS

Truewind.

N. Wind Rose Chart. Digital Image. AWS Truewind.

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Appendix C : Community Assessment: Site Maps

Figure 49: Jacobs Ladder Political MapB

To Ocho Rios

To Moneague

Figure 50: Jacobs Ladder Topographic MapL

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Appendix D: Wind Data

Figure 51: Preliminary Wind data for MSC Jacobs Ladder Compiled by AWS TruewindM

Figure 52: Wind Rosette Showing Primary Wind Directions At Jacobs LadderN

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Appendix E: Needs Assessment Evaluation

Before th