As part of their web video series The Solar Road Tour, local full-service solar installer ReVision Energy put together this video of a near net-zero apartment building in Portland, Maine. This 3-unit downtown apartment building – located in the heart of Portland, Maine’s East End – features air source heat pump (ASHP) heating, solar thermal for domestic hot water throughout the building, and a photovoltaic system that offsets more than 1/3 of the building’s electricity use. The building is superbly well insulated so that the heat pumps can easily cover the building load – no fossil fuels burned here, ever!
Paul Ledman: I’ve always been interested in energy efficiency – I used to rebuild old brownstones in New York City many years ago in Carter years when everyone was talking about how we needed to be energy self-sufficient. The technology wasn’t very good then but there were things you could do, but we seem to have lost the concept somewhere along the way – maybe in the 80s? – that efficiency was a good thing to do.
Buildings in Maine are so old, so leaky and so drafty that you’re basically heating the atmosphere every time you turn on your boiler. The key to all of this is that we don’t need much energy because we don’t waste. You start with the insulation – our insulation is far, far in excess of the minimum standards, it’s a very tight building, it just doesn’t lose heat. Period.
We realized that our [heating] load could be covered with an air source heat pump, which is a very common technology used around the world, and we could also use a heat recovery ventilator, which takes the warm air we usually expel out the windows in the winter, and instead takes the warm air from that exhaust and heats up the fresh air to a degree, so you are not wasting the energy over and over again.
Those two technologies alone would save a tremendous amount of energy, but we went to the next level. We have a solar hot water system … which will generate about 70% of the hot water we need year-round. We [also] installed a solar photovoltaic system which generates our own electricity. Much of what we use, we generate ourselves. And once you’ve paid back your capital costs, you have no operating costs. So how can you not do it? If you’re going to build a house, and you look at the costs, and you look at the numbers, how can you make a decision to go with oil? Or with gas? When you cut through the advertising, and when you cut through the hype, the bottom line is that traditional energy prices will continue to go up, and there are alternatives that are available now. This house is an example of how you can use those things cost-effectively for an incredibly comfortable lifestyle and be independent.
ReVision designed and installed the solar energy systems for the project, which was a collaboration between the homeowner, Paul Ledman (Eco Capital Partners), Kaplan Thompson and Island Carpentry (Mike White). ReVision Energy frequently collaborates with local green building partners for high performance homes, contact them to learn more!