. A five year warranty provided by the installer of the system for defective workmanship. . A two

20 Commonwealth Solar. (2008). Solar Photovoltaic Rebates: Program Manual. Retrieved September, 2008, from http://www.masstech.org/SOLAR/Commonwealth%20Solar%20Program%20Handbook_v2_070108.pdf
. A five year warranty provided by the installer of the system for defective workmanship. . A two years product and 20 years performance warranty on the system modules. . A five year warranty on the system mounting. . A ten year warranty on the power inverters.
Other Requirements:
. The equipment installed must be new. . The equipment installed must meet the Underwriters Laboratory standard 1703
. All modules, inverters, and production meters must be on the California Energy Commission’s list of eligible renewable energy equipment. . All photovoltaic projects must have a dedicated production meter . Systems over 10kw must have a production tracking system (PTS).
A solar-energy system purchased for the principal residence of an individual is fully exempt from Massachusetts sales tax. In addition, solar-energy systems purchased for commercial, industrial, or residential use are exempt from property tax over their first twenty years. A 15% tax credit up to $1000 against personal state income tax is available to any owner or tenant for the purchase and installation of a solar-energy system in their primary residence. The system installed must be new, in compliance with all performance and safety standards, and be expected to last at least five years. Renewable energy credits (RECs) are based on the environmental attributes associated with the generation of electricity. They do not have to do with the electricity itself, but the means by which the electricity was generated. Renewable Energy credits exist for two primary reasons. For one, the state government sets Renewable Portfolio Standards on utility companies. These require a certain amount of electricity produced by these companies to be from renewable sources. Utilities that do not produce enough electricity from renewable sources may buy RECs from those who produce energy from renewable sources. RECs may also be sold to consumers who want to be sure that the electricity that they are consuming comes from renewable source. RECs may be sold to various state and nationwide organizations. Current prices for these credits range from .5 cents a kilowatt hour to 5.5 cents a kilowatt hour.
Net metering is an electricity agreement between a consumer and their electricity provider which allows the consumer to offset some, or all, of their energy cost by running the electric meter
backward via producing a surplus amount of energy. Running the electricity meter backward occurs when a consumer is producing more energy than he or she is currently utilizing.21 As a result, in any month with a positive net difference, the customer may choose to receive a credit equal to the average monthly market price of generation per kilowatt hour. The utility company cannot impose special fees on net metering customers.22 The state of Massachusetts currently enforces all investor-owned utilities to offer net metering but does not require municipal utilities to abide by the same standard.
21 CalFinder. What is net metering? Retrieved September, 2008, from http://solar.calfinder.com/blog/solar-information/what-is-net-metering/
22 DSIRE. Massachusetts Incentives for Renewable Energy. Retrieved November, 2008, from http://www.dsireusa.org/documents/Incentives/MA01R.htm
23 DSIRE. Massachusetts Incentives for Renewable Energy: Net Metering. Retrieved November, 2008, from http://www.dsireusa.org/library/includes/incentive2.cfm?Incentive_Code=MA01R&State=MA&CurrentPageID=1
The current standard for net metering was enacted on July 2, 2008, and is applicable to residential, commercial, nonprofit, industrial, school, institutional, agricultural and governmental sectors.23 Net metering customers are grouped into three classes (I, II and III) which are determined by system size. The most common size class for residential and a small commercial is Class 1. Class 1 describes any system which is less than or equal to 60kW. The second and third class apply to systems which are 1MW and 2MW, respectively. For Class 1 solar installations, credits may be carried forward from month to month indefinitely. These customers may also choose to transfer the credits earned to another customer on the same utility.
2.4.2 Factors in Determining Economic Feasibility
The final result of this project will be the determination of whether or not the installation of a solar panel system is economically feasible on Wesley United Methodist Church. Before we proceed with economic analysis of the solar panel system at Wesley United Methodist Church, we must outline what factors determine economic feasibility. The startup costs, operating costs, revenue projections, and financing options will all need to be considered.
In this solar panel installation, the start up costs will include product cost, installation cost, and the cost of inspection and certification. The product cost will include all of the various hardware components of a solar power system, including the actual solar panels, the frames to mount them on, the inverter to convert the DC power to AC, and the grid tie system which will allow it to connect to the power grid. There will also be the cost of a professional installation, as this is a requirement for the MTC grant. Finally, there is the cost of inspection and certification, which is also required to receive the aforementioned grant. All of these costs will be reduced by the grants and incentives outlined in the previous section to determine the overall startup cost. After the solar panels are installed and generating electricity, there is an operational cost that goes along with maintaining them. Solar retailers often give information about the maintenance cost of solar panels, which includes any maintenance or repairs or replacement of damaged solar panels. Even smaller costs, such as the cost of shoveling snow off of the solar panels during the winter would fall under this category.
The money generated from the solar panels would ideally offset the costs mentioned above. Money generated from solar panels can be broken into three main categories: energy saved, energy sold-back, and renewable energy credits. The primary category, energy saved, will be the difference in cost between the electric bill with the solar panels installed and what the electric bill would have been without them installed. In the simplest scenario, this would be the number of kWh generated that does not exceed the amount used multiplied by the cost per kWh. The next category, energy sold back to the electric company, would be any amount of electricity generated by the solar system that exceeded energy usage and could be sold back to the electric company. The final way to profit from solar panels is through the sale of renewable energy credits to other corporations. Corporations are regulated by the government to meet a certain quota for the use of renewable energy. Some generate their own
renewable energy; however, others buy credits in lieu of generating it themselves. These credits have their own market, and the proceeds from of the sale of credits may be in addition to the money received from the previous two categories. The final consideration when analyzing the feasibility of such a project is the available financing. Solar panel systems generally require a large capital investment. Much of this cost is typically paid by borrowing from banks or investors. Important considerations when looking for financing are the interest rate, the duration of the loan, the monthly payment, and the required down payment.
2.5 Similar Case Studies
There are many factors to consider when analyzing the feasibility of different solar systems for Wesley United Methodist Church. We investigated a number of case studies to evaluate the factors in a feasibility study in the domain of renewable energy.
2.5.1 Holy Name Wind Power Feasibility Study
The Holy Name wind power feasibility study investigated the feasibility of installing a wind turbine at Holy Name high school.24 The main task of the project was broken into various parts. First, site data was gathered, including wind speeds, current energy usage and property characteristics. Using this data, a number of sites were proposed and compared against a set of heuristics to determine the best possible location. Then, based on the size of the installation that would be required to provide an adequate amount of electricity, a list of possible turbines was made. These turbines were then compared against each other to find the best possibility. Also, a mathematical model was created to determine the economic feasibility and break-even points using different financing options. Five, seven, ten, and twenty year loans were simulated and return on investment figures were calculated for each simulation. Grants, net metering, energy certificates, tax incentives, and different loan options were all
24 Foley, B., Forbes, T., Jensen, H., & Young, A. (2006). Holy Name High School Wind Turbine Feasibility Study. WPI Library: http://www.wpi.edu/Pubs/E-project/Available/E-project-121306-104131/
explored. The report concluded that 60 to 70% of the school's electric bill could be saved through the installation of a turbine. Although this project did not focus on solar panels, there are many aspects of it that are applicable to any renewable energy feasibility study. The process of determining feasibility itself, from site analysis to comparing different technologies to creating an economic model, is similar regardless of which renewable source is considered. Also, many of the incentives for renewable energy are similar for both wind and solar systems.
2.5.2 Solar Feasibility Study of a Learning Center at WPI
The Feasibility Study of a Solar Learning Lab at WPI was an incredibly insightful case study due to its similar location to our target and the use of photovoltaic panels.25 The goal of this Interactive Qualifying Project was to determine the feasibility of acquiring a Solar Learning Lab somewhere on the WPI campus. A Solar Learning Lab would give the students of WPI the ability to study the effects of solar energy without leaving campus. While the objective of this project was not to generate power for the school, the similarities between this project and ours gave us a good idea of the steps we would have to take to determine if the meteorological conditions were acceptable for using photovoltaics.
25 Wailgum, J., Ledue, J., Chapman, J., & Al-Beik, H. (2003). Feasibility study of a solar learning lab at WPI. WPI Library: http://library.wpi.edu/cgi-bin/Pwebrecon.cgi?BBID=251492
26 Heliotronics. Heliotronics Data Acquisition Systems. http://www.heliotronics.com
A Solar Learning Lab is the term used to describe a photovoltaic system integrated with a Heliotronics educational monitoring system. 26 The entire system is used to bring current solar information to a computer display where students are then capable of manipulating the data to generate graphs and plot trend lines. A Solar Learning Lab is designed to provide students with a hands-on understanding of how photovoltaics work without purchasing a large system.
One of the first tasks that the IQP group undertook was to determine an acceptable location for their solar panels. This meant that each possible location must agree to a set of criteria and is ranked on how well it matched. Several considerations were safety, space and availability, accessibility, security, connectivity, sunlight exposure, and grid tying considerations. The final location chosen was "Daniels Hall". This building fit each of the criteria and gave the best possible outcome for the project. The decision process of choosing a location was very enlightening and paralleled our own process. The next step of the group was to establish their projected results. The installation process was reviewed many times to determine what spot on the roof of Daniels Hall provided the easiest installation. Several experts from various contracting companies were brought in to provide their detailed analysis on the location and installation situation. This process established the cost of the Solar Learning Lab as well as the installation and maintenance, which enabled the group to generate a cost analysis of their project. The last remaining step was to establish an acceptable marketing campaign that would sell WPI on their idea. The group presented their project's financial aspects, academic benefits, and environmental friendly appearance. Each subject was presented in a fair and unbiased manner that depicted the strengths and weaknesses of the project.
2.5.3 Janssen Ortho LLC Solar Power Feasibility Study
Janssen Ortho LLC is a subsidiary of Johnson and Johnson based in Puerto Rico and had an IQP team evaluate the feasibility of a solar panel installation27. This project discussed the history of Janssen Ortho LLC and the importance of being environmentally friendly to the company (17). Johnson and
27 Sands, E., Moussa, O., Meagher, G., & Lemaire, J. (2004). Solar Energy at Janssen Ortho LLC. WPI Library: http://library.wpi.edu/cgi-bin/Pwebrecon.cgi?BBID=253817
Johnson follow a credo, part of which states that it will be a leader in helping the environment. Janssen Ortho LLC consumes 33 million kWh yearly, certainly too much to be generated entirely from solar power. The project group consulted with Powerlight Corporation, a world leader in solar installations, and eventually recommended a pilot installation. The pilot system would product 101kWp (kilowatts peak), less than 1% of Janssen Ortho’s power consumption; however it would demonstrate to the community that they were interested in alternative energy. This group also proposed a possible larger scale solution that would involve the construction of a solar panel mounting structure over the parking lots. Due to the high expense of building on top of the parking lots, the group only recommended pursuing this if they were able to get 70% government aid. The group also created brochures for employees and for the community to spread information regarding the benefits of solar projects.
3. Methodology
In order to determine the overall feasibility of installing a photovoltaic system on the roof of the Wesley United Methodist Church, we divided this task into five sections. The first section, site analysis, was concerned with obtaining the physical layout of the roof space suitable for panel placement, as well as determining relevant meteorological data that was needed for energy calculations. The second section, possible solar panels and placements, dealt with determining the criteria and system that would be used to select the best panel style for the church. The third section investigated what the effect of different orientations and configurations of the panels would have on the amount of energy that could be produced. Economic feasibility of the systems, the fourth section, investigated what economic factors and assumptions should be used in order to create an accurate economic model of the solar panel system as an investment vehicle. In the final section, social implications, our objective was to determine what social factors might come into play that could help or hinder the support for the installation of a photovoltaic system.
3.1 Site Analysis
Given the relationship between the sunlight available in a region and a solar cell’s energy output, site analysis was one of the greatest influences on the feasibility of a photovoltaic project. Given the church’s geographical location in Worcester, Massachusetts, several factors were considered. Each factor dealt primarily with the sunlight available or the geographical layout of the designated site. Factors such as location, average sunlight, daily shadows, obtrusive objects, and structural positioning combined to form the project’s site analysis. To obtain the data needed to form our site analysis, the project was divided into a number of domains. The first dealt primarily with the meteorological conditions of Worcester. This domain sought to answer the question of how much sunlight is available, as well gather any information that would ease the calculation of how much energy can potentially be
produced by an array of solar cells. The second domain dealt with the structural layout of the roof space at the Wesley United Methodist Church. This domain was responsible for determining where solar panels could be placed by taking shadows, obtrusive objects, and structural support into consideration. The third domain consisted of gathering and summarizing the current energy usage of the church. This data could be used to form estimates about how much money could be saved through the energy generated by the installation of a solar panel system. The last domain, concerning the installation of solar panels, dealt with determining what factors would come into play when installing the panels onto the roof, as well as integrating the system into the electrical grid.
3.1.1 Meteorological Analysis
Gathering and summarizing meteorological data was a vital aspect for creating the site analysis. Obtaining meteorological data is done with relative ease these days. One of the greatest resources of weather data is provided by GAISMA28. It includes information such as monthly atmospheric clearness as well as sunrise and sunset durations. Most importantly, GAISMA offers a monthly insolation calculation. Insolation is a composite measurement that summarizes the amount of solar radiation that an area receives. The insolation value is a numerical value that represents the average kWh/m2/day in a given month. These values are exceptional tools that encapsulate various meteorological events; for example, this calculation encompasses the change in sunlight due to cloudy or partially cloudy days. The result is a value that describes the amount of solar radiation (sunlight) available in a given area per day. This average was used in the calculation of how much energy would be produced by a given solar panel. This allowed for relatively accurate calculations of future energy production which was essential for determining when a return on investment could be realized.
28 GIASMA [Online] www.giasma.com
3.1.2 Layout of Roof Space
To determine the layout of the roof space, we took preliminary measurements of the roof. With these basic dimensions, we were able to calculate a best-case scenario for mounting solar panels. This best-case scenario acted as an upper bound on the size of the system that could be installed. With the preliminary measurements, we were also able to obtain a set of plans for the roof, with detailed dimensions. From this, a simpler and smaller-sized CAD drawing was created using the set of plans and the measurements taken on the roof. However, the primary problem with taking our measurements at only one time of day was that they didn’t include all possible shadowed areas. Another problem encountered was that we didn’t initially record the locations of any other possible shadows, such as trees or the chimney, which could cast a shadow over several panels at different times of day. Our research on different panels showed that panels should not be partially shaded. It was therefore decided that we would visit the site at different times of day to take detailed measurements of where shadows fell. This allowed us to create a printed plan of the roof space, including areas representing the shaded portions of the roof, using a software modeling program. With this information, a more accurate calculation of the possible area suitable for a photovoltaic system was made. We also determined the necessary spacing of an array using different panels, to figure out how many panels could effectively fit onto the roof’s surface. Inter-panel spacing was important because tilting the panels for the optimum angle of the sun could potentially cause them to cast shadows onto each other. Using trigonometric calculations, we found the spacing necessary between panels to avoid these types of shadows, as well as determined the maximum number of panels as a result of this spacing. This maximum number of panels allowed us to determine how much power could be harnessed in each of our panel configurations.
3.1.3 Energy Usage
We found it necessary to gather previous energy data from the church in order to gain a better understanding of how a solar panel system would affect the overall amount of energy that the church could save. Previous electric bills contained the number of kilowatt hours consumed by the church, as well as the price paid for these hours. Using this data, we were able to summarize the trends in energy usage over the course of the year, and more importantly, compare this energy data to the estimated energy that could be produced by a solar panel installation. The electrical purchasing history of the church also gave us an initial cost of electricity, which was very useful in our economic analysis.
3.1.4 The Installation Process
Researching the installation process was another important aspect of the site analysis. This involved contacting local installers and analyzing the Worcester Code Enforcement to better understand the electric codes relevant to the installation of a photovoltaic system. In addition to this, we contacted National Grid, the power supplier for the church, to find any other regulations pertaining to connecting the church’s solar panel system to the electrical grid. It was also important to determine the nature of the materials that the roof was composed of, and what methods of mounting the panels would work best on these surfaces. Research was done to create a contact list of local installers who would be able to install a system if it were found to be feasible.
3.2 Analysis of Solar Panels and Systems
In our pursuit of the most economical solar panel solution for Wesley United Methodist Church, we came across many possible options for panels, inverters, and other equipment, each with their own costs and benefits. In order to determine which solution was optimal, we enumerated a list of criteria that was used to evaluate each solution.
We decided that the best metric for evaluating a solar system was the cost per Watt produced by the panel. Naturally, the lower this number, the greater energy production that can be purchased for the same dollar amount. This criterion will lead to a better return on investment and fewer years until the church recovers their initial capital. We determined that the second most important criterion for determining the feasibility of a solar panel system was its durability. Less durable systems would incur higher maintenance costs and exhibit a shorter lifetime of operation. The longer the solar system lasts the more energy the church will be able to obtain from it. We decided that the efficiency rating of the photovoltaic panel was important because it is directly related to the maximum power a system using the panel could produce. The church had a set amount of space available for a solar installation. The higher the efficiency of the solar system, the higher the amount of power we could get from a system covering the same amount of space. The availability of a certain solar technology also factored into our analysis of feasibility. There are long waiting lists for some of the newer solar panel technologies, such as thin film solar panels. For this criterion, there was a trade-off between only looking at what is readily available and waiting for a better technology to become available. The weight of the solar panel system was important. The roof at Wesley United Methodist Church is able to support 35lb per square foot, so any system heavier than that was disregarded.