A Landmark Project

A couple of years ago, I led a team of professionals on an American Recovery and Reinvestment Act (ARRA) project for the General Services Administration (GSA) at the General Emmett J. Bean Center in Indianapolis, Indiana. GSA selected the Bean Center for a landmark pilot project involving the design of an expansive 2-megawatt rooftop photovoltaic (PV) array of over 6,000 solar panels. As part of the project, we also designed a rooftop laboratory of four other PV technologies, with the purpose of using the collected data to evaluate the performance of different solar arrays in a Midwestern climate. The Department of Energy, Sandia National Laboratories, and New Mexico State University use projects like these as part of GSA's Green Proving Ground Program to evaluate innovative sustainable building technologies and practices.

Measurement was Critical

Instruments and data collection devices tracked the performance of both the main array and those contained in the PV lab for the first year of operation. This valuable information was fed back to the team for evaluation. Our design included a sophisticated weather station that tracked clear-sky and cloudy-sky performance as well as temperature, sun angles, and radiant energy. This allowed each laboratory technology to be tested and evaluated in all weather conditions. Collected meter data allowed further analysis by recording energy production and calculating the system efficiency, which was used to determine the life cycle cost and system payback of the systems while investigating different operations and maintenance programs.

The Results are In

Our design for the commercial-scale high-efficiency crystalline PV system performed almost exactly as our engineering models predicted, producing nearly 4% more power than anticipated and having a 19-year life cycle. Not only did this validate PV solar as a viable energy solution for the Midwest, but it also authenticated our systems modeling method as a highly accurate performance guide. The PV laboratory results showed that the different panels all performed equally well in a Midwestern climate, and that the determining design factor for future arrays should be based primarily on the cost/watt. Secondary consideration should be given to the amount of space available compared to the amount of power production desired.

I would like to extend my congratulations to the entire Dewberry design team on an incredible job that has only just begun to produce valuable data for the future of renewable energy solutions!

The official study and report for the Bean Center photovoltaic laboratory performance is available on GSA's website.