Plymouth NH Wastewater/Sewer District SolarReliance on fossil fuels hits towns and local government in the pocket book just as much as it does homeowners and businesses. In times of tight budgets on every level of government, saving money thanks to efficiency makes good fiscal as well as environmental sense. Moreover, town buildings can serve as a model for their communities. Thinking “big” on the local level and that can cause ripples outward into the community.

This kind of thinking is what drove Steve Kahl and Bob Reals of the Plymouth (NH) Energy Commission to submit four DOE grants for projects at their local water and sewer districts (Plymouth Village Water and Sewer District-PVWSD). Their vision? Take a conventional double-wide trailer used for office space and turn it into an energy efficient, net-zero building.

“The idea came from a basic concept: let’s demonstrate what is possible,” says Steven Kahl, architect of the grants, “Unlike the town hall, these administrative offices are housed in a double-wide trailer, which we thought more people could relate to. We wanted to make the point that any building can benefit from efficiency improvements. We had plenty of naysayers that were sure energy efficiency and renewable energy doesn’t work, so we wanted to show, not tell, a different story.”

Making It Happen

schematic of net zero retrofitThe successful funding of two DOE grants, plus local utility and state rebates made the project possible. One proposal was for the efficiency and super-insulation part of the project, where the fairly conventional building benefited from 20″ of cellulouse and 2″ of spray foam insulation in the ceiling, raising it to R80, 4″ of foam and 6″ of fiberglass batts in the walls, raising them to R-43, as well as 5″ of foam insulation in the basement and improvements to doors and windows.

Another grant funded renewable energy inputs: solar photovoltaic systems on the town library, elementary school, and PVWSD administrative office. The 9.4kw grid-tied solar electric system will generate roughly 11,900 kWh annually, providing for all of the electric needs of the space – including electric heat! The choice to maintain electric heat, and offset it with clean solar power, means that the building generates all of its own energy. In other words, it is ‘net zero.’

The Results

solar pv net zero resultsAccording to Kahl, the project went smoothly and results have been impressive.  “I had solar installed on my home, too, and I can say with this one ReVision came with their usual ultra professional design and installation.  The solar array started banking electricity for winter use as of this March, and has so far generated a surplus of almost 4,000 kWh.”

Of course, it’s not just about the numbers – a well insulated building feels better, too.  “The occupants report greatly increased comfort after the retrofit due,” Kahl says, “The project resulted in a 70% reduction in air infiltration, resulting in an indoor environment that is considerably more consistently heated and comfortable.”

This demonstration project was funded by an ARRA grant, NH Office of Energy and Planning, Department of Energy, the NH Electric Coop and the Plymouth Village Water and Sewer District.  All of the technologies used in the project are cost-effective for homeowners, who in NH can now benefit from a recently revived state rebate program.