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.
Finally, we considered the carbon footprint of the manufacturing process as we analyzed solar panel feasibility. Some manufacturing processes place a larger burden on the environment than others. Because one of the greatest benefits to using renewable technologies is the positive effects they have on the environment, this was something to consider. It was not, however, as important as some of the previous criteria because the most important part of this study was to find a solar solution that would be economically feasible. We would not recommend proceeding with a solar panel solution that caused a
negative cash flow, so it was more important that we found a solution that is economically feasible than that we found the most environmentally friendly solution. Certainly, any renewable energy source that gets implemented is significantly better for the environment than continuing to use nonrenewable resources for energy production. In order to determine which solar panels were best suited for this project, we first discarded any that were too heavy for the roof to support. Next, we performed a competitive analysis on the remaining panels. Competitive analysis is a process that can aid in making decisions when there are many factors to consider. First, we created a list of criteria and weights, which can be seen in the table below. Weights were assigned to each of the criteria, based on the decided importance of each. The different solar solutions were then rated in each of these categories. Finally, each weight was multiplied by its respective rating and then all of these results were tallied for each solution. At the end of this process, each solution was given a number representing its overall score.
Criteria
Weight
$/Watt
10
Durability