Unity College house is an energizing experiment

BY SCOTT MONROE
Staff Writer

12/08/2008

UNITY -- The first thing Mitchell Thomashow did when he got back home on a recent evening was check the outside meter.

The numbers weren't as good as they have been in recent months: His house used 958 kilowatt hours and generated 1,210, for a net gain of 252. Even so, "we generated more electricity than we took in," Thomashow said. "The gap was bigger a month ago. It was in the 400s."

Thomashow, president of Unity College, has gotten used to this almost daily habit, which is just one of several routines that have become part of living in the solar-powered Unity House.

When he arrives inside, the temperature is 65 degrees. Thomashow takes out a log book and writes in the day's electricity use; he's been keeping tabs on the house's energy use for most of the last four months since he and his wife, Cindy, moved in to the college's new house for the president.

The Unity House is a modest, 1,900-square-foot, one-story house tucked away below a parking lot for dormitories and other buildings -- just a stone's throw away from the heart of the Unity College campus. It was designed by the Bensonwood Co. of Walpole, N.H., which is one of the founders of the "open prototype" design used for the Unity House.

Unity House Blog

The timber-frame house includes a large common room (kitchen, living and dining spaces) with an adjacent guest room, an office area/ small music studio, and a bedroom. A small utility room contains the house's solar hot water heater.

Adjustable walls throughout the house, made of recycled wood materials, enable the Thomashows to make extra room for accommodating visitors. The experimental house is intended to serve as a lesson -- and perhaps a model -- for environmental sustainability. The house, Thomashow said, illustrates how it's possible to have lower energy bills, reduced greenhouse gas emissions, and less exposure to mold, mildew and other indoor toxins.

"The warrior in me wants to meet the zero-carbon challenge," Thomashow said.

The Thomashows are also trying to be more conscientious stewards of their environment. That comes across in the little things, such as using energy-efficient light bulbs and shutting off all lights that they're not directly using. Also, all of the household appliances they use are Energy Star-rated.

Soon, Cindy Thomashow said, they will be getting all new furniture made by Green Design Furniture Co. in Portland to further promote the sustainability theme.

They expect the Unity House will be certified as a "Platinum" home -- meaning, it uses the least amount of energy, water and natural resources -- by the Leadership in Energy and Environmental Design Green Building Rating System. LEED measures a building's performance in sustainable site development, water savings, energy efficiency, materials selection and indoor environmental quality.

The Thomashows even try to unplug all appliances that they're not using at the moment to reduce the amount of "phantom energy" that's released from gadgets and appliances (for instance, a cell phone charger plugged into an outlet).

Even with all they've done to reduce their energy consumption, "there's more we can do," Thomashow said. "We haven't even begin to monitor appliance use."

By the end of October, the Unity House was amassing a net gain of 420 kilowatt hours a day, and that lasted until mid-November. Lately, though, with cloudier days and colder temperatures, Unity House hasn't generated quite as much energy.

"Come April, I think we'll be generating more again," he said. "We may slip behind after the winter, but I'm convinced a year out we'll be generating more than we use."

The Thomashows are certain, though, that after a one-year cycle, the house will have saved a lot of energy and money. Because of the investments made in the solar panels and the house, they will not have an energy bill from Central Maine Power. In fact, because they are producing more than they're using, the Thomashows will receive energy credits with Central Maine Power Co.

A monitor on the wall tells the Thomashows in real time what their overall energy use and production has been. On an evening this past week, the monitor said they had produced 1,683 kilowatt hours of electricity so far, saving $235 and 2,187 pounds of carbon.

Of the Thomashow's energy use, heat for the house and using the stove are the two top contributors. "This house demands that you take in active role" in its heating and cooling, Cindy Thomashow said.

The Thomashows said the house is operating better than they expected. There are days, even lately, when they don't need to turn the house's heat on at all, and they typically turn the heat off every night.

The house is well insulated and designed to retain its heat with thermal mass system and concrete floor. Recently, 55 people visited the Unity House for an Art of Stewardship conference, Thomashow said, and the temperature increased by about 7 degrees during two hours. That generated heat allowed the Thomashows to keep the house's heat turned off for two full days.

What's interesting is that the temperature in the house is even throughout; there are not any hot or cold spots like you would normally find in a house, he said.

"I'm really comfortable in this house," Cindy Thomashow said. "People come in and are blown away by the beauty of the place. We want people to see that you can live very comfortably and be environmentally conscious."

Mitchell Thomashow said he gets up at around 5 a.m. each morning and the first thing he does is check the temperature in the house after a night without the heat on. The lowest the temperature has been, he said, is 58 degrees.

Next, he checks the day's weather forecast. If it's going to be sunny most of the day, he won't turn the heat on. If it's going to be cloudy -- and the solar panels won't be absorbing much sunlight to power the hot water heater -- then he'll turn on the heat on.

"That's an active choice," he said. "The house is designed to make you aware that these things are important."

Going forward, Unity College plans a similar approach to its campus buildings, with plans for solar, wind and geothermal heating, plus more conservation efforts aimed at making it a "zero-carbon" campus.

"This," Mitchell Thomashow said, "is the first stage of a long journey."