AbstractPhotovoltaic cells capture the sun’s energy and convert is into electricity. Many college

campuses, such as Harvard University, Smith College, and the University of Vermont have

already installed and implemented this energy saving technology. Based on these

precedents, the Sun Riders studied the potential for photovoltaic cells at WPI. The group

performed a cost analysis of environmentally friendly photovoltaic cells and calculated the

payback period for installing a minimally complicated configuration of this technology on

the rooftops of six buildings on the WPI campus. The cost savings would be $1,779,000

over the next 25 years with the initial cost factored in. Without any rebates, the payback

period of this project is 19.5 years.

ConclusionSolar energy is technologically well developed, and it has great potential to contribute

to energy savings on our campus. It is clean, sufficient, and can be relatively economical

depending on the manufacturing process used. There is much to explore before making a

final decision about whether it is feasible for our campus.

Over the next twenty-five years, it is likely that there will be a vast amount of research

and development done on solar technology to better improve its efficiency. If the efficiency

of solar panels exhibited a strong increase in the coming years, then a project like this may

sound more appealing to this campus in the not too distant future.Rebates are the key to short-term profitability. However, these are only available to

tax-paying institutions and PV projects under 500kW. We suggest that if WPI wanted to

install photovoltaics, they should explore projects under 25 kW, where MTC rebates of $3.50

per Watt are available. The details of such a project can be explored further by other groups.

Resources“Bing Maps.” bing.com Web. 8 Dec. 2009. This is an online map search engine.

“Create a Graph.” ed.gov. Web. 8 Dec. 2009.

This is a online grapher.

Deutschen Gesellschaft für Sonnenenergie. e.V. “Photovoltaics: Solar Electricity and Solar Cells in Theory and Practice.” solarserver.de 14 Nov. 2009. Web. 14 Nov. 2009. A web page containing general information about PV cells.

Energy Information Administration(EIA). "Electric Power Annual." 21 Jan. 2009. Energy Information Administration. 18 Nov. 2009. This article divulges annual statistics about electricity consumption and prices.

----"Annual Energy Outlook 2009 With Projections To 2030." Mar. 2009. Energy Information Administration. 18 Nov. 2009. This is an article that divulges the 2009 EIA energy outlook.

Environmental Protection Agency. "Greenhouse Effect." 23 Oct. 2006. Environmental Protection Agency. 9 Sep. 2009. This article gives an overview about the greenhouse effect.

Evergreen Solar. "Our String Ribbon Wafers - Genius In Its Simplicity." Evergreen Solar. Web. 2 Dec. 2009. This is a web page about the String Ribbon Wafer Technology that Evergreen Solar employs in their solar panels.

Function Grapher. “Function grapher – advanced version.” function-grapher.com. Web. 8 Dec. 2009. This is an online function grapher.

“GE Plastics Material Developments for Emerging Green Industry.” jobwerx.com. Web. 8 Dec. 2009. A high resolution picture of solar panel

Gevorkian, Peter. Sustainable Energy Systems Engineering. New York, NY: The McGraw-Hill Companies, Inc. U.S, 2007. Print. A book contains general information about various types of sustainable energy systems

Hodges, Alan W., and Mohammad Rahmani. “Fuel Sources and Carbon Dioxide Emissions by Electric Power Plants In The United States.” University Of Florida: IEAS Extension. Web. 5 Nov. 2009. This article appears to be about the carbon emissions from coal powered plants that are warming the planet. Statistics of carbon

emissions from each state in the United States are shown.

Gevorkian, Peter. Sustainable Energy Systems Engineering. New York, NY: The McGraw-Hill Companies, Inc. U.S, 2007. Print. A book contains general information about various types of sustainable energy systems

Monniaux, David. “Wikimedia Commons.” wikimedia.org. Web. 8 Dec. 2009.

A picture of photovoltaic cells

Pegg, J.R. "Coal Power Soot Kills 24,000 Americans Annually." Enviornment News Service. 10 Jun. 2004. Web. 23 Nov. 2009.

Stauffer, Nancy. "Building Solar Cells From Ribbons." Massachusetts Institute of Technology. 2 Dec. 2009. This is an article that explains the String Ribbon Wafer manufacturing process.

GoalTo examine the feasibility of photovoltaic systems on WPI campus

AcknowledgementsWe would like to give special thanks to the following individuals and groups: William Grudzinski, Chief Engineer, Power Hourse, WPI; Frank Horanzy, Lead Electrician, Facilities, WPI; Marylou Horanzy, Financial

Resource Coordinator, Facilities, WPI; John Orr, Provost & Senior President, Academic Affairs, WPI; Richard Patterson, Senior Estimator, Barr and Barr Builders; Tara Probeck, Marketing Communications Specialist,

Marketing and Communications, WPI; Yvette Rutledge, Customer Service Coordinator, Facilities, WPI; Leonard Sarapas, Corporate Director, Environmental Health & Safety, Boston Scientific Corporation; Brian

Savilonis, Professor, Mechanical Engineering, WPI; George Shakan, PLA, WPI; Erik Silva, PLA, WPI; David Spanagel, Assistant Professor, Humanities & Arts, WPI; Dianne Vanacore, Print Production Coordinator,

Marketing and Communications, WPI; WPI Bartlet Center Staff; Academic Technology Center staff, WPI;

Solar Salvation at WPICarl Haroian, Sam Patterson, Nathan Sarapas, Cathy Wang

Faculty Advisor: David Spanagel

Methodology1. Decide which buildings to put solar panels on

2. Decide which solar panel to use

3. Decide which inverter to use in order to convert direct current to usable alternating

current

4. Determine the amount of sunlight Worcester experiences per unit area annually

5. Determine the efficiency of the proposed system

6. Determine the projected electrical production of the proposed system

7. Determine the annual savings based on the projected price of electricity

8. Determine the amount of time necessary for the system to pay for itself

AnalysisBased on the satellite images from Bing Maps, we determined the available roof

space on all buildings to be 8,890 square meters.

Each solar panel as proposed would be tilted at an angle of 43 degrees above the

horizontal. In order to prevent one panel from shading another, we determined that the

amount of space needed for each panel would be 3.11 square meters.

By dividing the total amount of space available by the space occupied by each panel,

we found that we could use 2,858 panels. We knew the dimensions of each proposed

panel, so we found that 4,087 square meters would be hit by sunlight.

We found that the average daily insolation in Worcester, MA for a 43 degree surface

is 5.299 kWh per square meter per day. Based on this number and our estimated

system efficiency of 14.6%, we were able to find an estimated electrical production of

our system. In 2009, the proposed system would produce 1,150,000 kWh. However,

the panels are expected to degrade in production by 0.6% annually.

The system would cost roughly $4,579,000. Rebates are not available for the

proposed system, so the payback period for the system is roughly 19.5 years. This is a

relatively long payback period, although 19.5 years is well within the solar panel

warranty of 25 years. We realize that those paying for a project would rather

experience short term profitability. Some other scenarios are briefly described in the

conclusion section.

Background

Electricity Cost/kWh vs. year

•Depleting oil reserves WPI Electricity Costs Vs. Year

•Rising world population

•Rising costs of energy

•Dependence on foreign oil

•Global Warming

•New Energy source needed

Solar energy is unharnessed and free for the next 5 billion years. Although it is

expensive, its cost is lowering as research progresses.

Traditional methods of making solar panels make recycling difficult. We propose to

use String Ribbon Technology panels from Evergreen Solar. These panels require less

energy during production and allow easy recycling.

Below is an image of our proposed solar panels, angled at 43 degrees above the roof

surface. To account for solar shading, panels must be separated 1.07 meters apart.