When Kate Stephenson bought her home in Montpelier in 2007, her overall goal was to be fossil fuel free- and use as much renewable energy as possible. But she knew there were going to be challenges. First, her house was built in 1876 - a classic Cape, which had zero insulation in the walls and an antiquated oil furnace. Second, her house was on a steep north-facing hillside on Prospect Street and therefore received very little direct solar gain.
First, reduce electricity loads
Kate’s first priority was weatherization- after an energy audit, she hired contractors to air seal the attic, and add insulation in the walls, basement and roof. She replaced a few leaky and rotten doors and windows, too. Then she installed a wood stove and switched over to heating the house primarily with biomass, a renewable energy source. And when the oil furnace finally died, she replaced it with a higher efficiency unit (unfortunately still on oil, since they don’t have propane) for backup. She upgraded to a more efficient electric hot water heater and installed LED lights throughout the house. Last year, she burned about 3 cords of wood and 50 gallons of heating oil and used an average of 500 kWh per month in electricity.
Second, switch to renewables
At that point, having reduced the electricity loads as much as she reasonably could, it was time to consider renewables- specifically using photovoltaic (PV) panels to produce renewable electricity. For years Kate had been paying extra on her Green Mountain Power (GMP) bill for “greener” electricity, but was fairly skeptical of what impact those dollars were really having to encourage the development of renewables. She knew it would not make sense to install PV on her north-facing roof or in her backyard, so when she heard about a new initiative to develop a community-owned solar farm in Waitsfield, she was interested.
Third, think local – consider community solar
Developed by Aegis Renewables, a locally-owned renewable energy company based in Waitsfield, the Mad River Community Solar Farm (MRCSF) was created to offer a new model for community solar. Basically, the 150 kW array is owned by an LLC comprised of its members, and each member purchases a share of the array based on their estimated electrical needs. They own the panels and the equipment, and have a 30-year lease on the land where the array is located (right behind the Big Picture Theater and Allen Lumber- if you’re driving down Route 100 you can see it on the hillside). Unlike many large scale solar arrays, the MRCSF,LLC owns all the renewable energy credits associated with the solar production. And the whole thing is owned and managed by the members—of which there are about 30 households—mostly from the Mad River Valley, but ranging all over Vermont. Since the array is in Green Mountain Power territory, anyone with a GMP account can apply the solar electricity credits to their account due to Vermont’s net metering laws.
It turns out, by buying the panels in bulk and installing 150 kW all at once, the price per watt on solar is much more affordable than installing panels on a roof. Kate bought 16 panels which total 4.96 kW at a price of $2.87 per watt. After the federal tax credit is taken, this comes down to $2.01 per watt, or just under $10,000 for the whole system. She’ll save money on her electric bill from Day 1, as the equivalent cost per kWh is lower than GMP’s current rate, and she anticipates that electricity rates are very likely to rise over the 25-year lifespan of the photovoltaic panels.