New Hampshire is home to many large river front mill buildings built in the late 1800s and early 1900s for production of all sorts of textiles, shoes and other goods. Here mills were all built on rivers to take advantage of water driven manufacturing machinery. Like so many mills this one has been restored to intense use by craftsmen and small businesses and is a vibrant base of commercial activity.
This building is just about the best roof one could ever find. It is flat, 5 stories up so not even a hint of shading and it faces due south. The power from the 120kw system is provided to the mill owner at a reduced cost. Because it is a PPA they paid nothing to install it and will receive discounted power for the next 25 years.