From Saxtons River Solar Electric
Rockingham Roasters. Photos courtesy of Saxtons River Solar Electric.
George Harvey
Saxtons River Solar Electric (SRSE) installs heat pumps, in addition to solar photovoltaics (PVs). Some people might ask why a solar installer would do that. After all, the technologies are completely different. The answer, however, is actually pretty simple.
“Heat pumps are the perfect companion to solar power. It really is a match made in heaven,” said Eric Shenholm, the co-owner of SRSE. “Solar and refrigerants come about as close as you can get to a free lunch in physics.”
The marginal cost of electricity from PVs is pretty close to zero. That is a fancy way of saying that it costs nearly nothing to use PVs, once the investment is paid down. And the marginal cost of running a heat pump is based mostly on the cost of electricity, which, as supplied by PVs, can also be pretty close to zero. Together, they can produce pretty good heat that is as nearly free as one can get. And that explains why SRSE and some other installers work with heat pumps.
In the start of his work life, Shenholm was actually heading in the direction of a career in refrigeration. He earned a license to work in refrigeration from the state of New York. Though he never actually used that license in those early days, the background turned out to be very handy as he got into the solar PV business. Heat pumps, which are used to heat or cool buildings, use precisely the same technology as refrigerators.
Shenholm recently told us about a special installation he had done in Bellows Falls. People driving north through downtown will note the building inside a major fork in the road, between Rockingham Street, which goes level to the left, and Canal Street, which goes downhill to the right.
It is a building of some historic interest, though it had seen better days. Shenholm said, “On a scale of benign neglect from one to ten, I’d say this building was at about nine.” It was purchased by Jennifer Gurley, owner of Rockingham Roasters, with the idea that with some fixing up it could be home to her business. She just had to rescue it first.
Interior of area where the cafe will be. The old beams are beautiful.
Shenholm said that the benign neglect included flooring over rot and painting by just putting fresh paint over old paint. So, Gurley understood that the building had to be redone by taking everything down to the frame. This gave her the opportunity not just to do cosmetic work, but to bring fresh vigor into the structure. New wiring, new heating, good air sealing, and good insulation were all part of the plan.
The building’s second and third floors, designed to be living quarters, could be insulated, sealed and heated in a pretty normal manner. However, the intended cafe on the ground floor, where people will enjoy drinking superior fair-trade coffee, presented special heating problems due to the large amount of glass in two walls.
Shenholm always uses Fujitsu heat pumps because of their ability to deal with low temperatures. Those heating his own home have performed well even at the lowest outside temperature experienced since installation of -14° F. The top two floors at Rockingham Roasters will be heated with a single heat pump rated at 36,000 BTU, with four indoor heating heads. The cafe area will be heated with two units of 24,000 each, which will amply compensate for the amount of glass in the walls.
Jennifer Gurley guides her business, Rockingham Roasters, on “a simple principle: to produce quality without waste.” The coffee beans are all organic, primarily fair trade, and roasted using electricity from hydropower. Packaging is compostable. The company is what she calls “low-brow on the branding and packaging.” And she said she is working to make the business an employee-owned company.
Saxtons River Solar Electric’s web site is saxtonsriversolar.com.
The Rockingham Roasters website is rockinghamroasters.coffee.
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