ROCKLAND – “This house is my laboratory,” said Rockland resident George Terrien.

At the moment, he was standing next to a trio of sophisticated heat pumps in the basement of his home on Broadway, explaining why he keeps a journal of temperature readings.

For 18 years, he heated and cooled his home and his water using a geothermal system. In what looks like any adorable Midcoast Maine garden the top of a pipe is the only evidence of the 425-foot-deep well that minimizes his carbon footprint.

Architect George Terrien stands next to the top of his 425-foot-deep geothermal well. Photo by Daniel Dunkle

Terrien estimates that it would have required 72,000 gallons of oil to heat his home for the same number of years without the geothermal process.

Terrien, 79, and his wife, artist Connie Hayes, purchased the house in 2001 and began extensive renovations. Terrien worked extensively as an architect, including starting his own firm. He has also worked as a consultant and an instructor.

With the house, he said he was able to make a claim and prove it with real data that older homes did not all need to be replaced, but could be updated in a way that saves both money and promotes a better environment. Tearing down all of the older homes in the country and replacing them with new energy-efficient homes would have a tremendous carbon footprint and environmental cost in terms of energy and resources used in the process.

“To replace our older residences, we would need half another Prudhoe Bay,” he said, referring to the largest oil field in North America.

George Terrien points out the heat pumps in his basement that form part of the equipment keeping his Rockland house environmentally friendly. Photo by Daniel Dunkle

Rather than rebuilding a wet basement, for example, he simply installs an industrial dehumidifier.

In addition to the geothermal system, the south-facing portions of the roof are covered in solar panels.

Those who built the house in 1850 could never imagine the level of technology that would be available to revitalize it. The house and what was at the time a detached carriage house were in disrepair when the couple bought it. They spent three years on the renovation before they moved in.

When the geothermal system was installed, Terrien was a pioneer in the process. The equipment was available, but local experience were not developed in setting such a system up.

Terrien explains that below the frostline, the earth and water stays at a steady temperature of 47 degrees. That does not sound very warm, but the consistency allows the system to capture energy.

He compares it to a refrigerator, which pulls energy (heat) out of the items inside and dumps that heat into coils at the bottom of the device. Those coils become quite warm, he said. Property owners can capture energy from these heat exchanges, use it to heat water and a home, and use the same steadiness of ground temperature to cool the air in summer. Heat pumps utilize that same principle.

Solar panels adorn the southern face of the home’s roof. Photo by Daniel Dunkle

Terrien said that for each unit of electrical energy he puts into the system, he gets four units of heat back.

He said in other countries such as Denmark, this is not unusual at all.

“If we can do it, we owe it to the world,” he said.

With the solar power in the mix, he said his electricity bills are less than $14 per month.

In addition, improvements to the insulation and windows not only help capture heat or coolness in the house, it also protects the couple from the noise of the busy street outside. The home’s superior ventilation also prevents road dust from making its way inside.

Terrien has been working with environment-saving technology throughout his career. He was the architect for the Maine Autobon Society’s headquarters in Falmouth in the 1970s. He created a solar power process to heat that building. In doing so, he had help from students and a mechanical engineering professor at the University of Maine in Orono.

The once detached carriage house is now part of the main structure. Photo by Daniel Dunkle

Today, he would recommend homeowners invest in air-to-air heat pumps or air-to-water heat pumps. Technology has advanced since he renovated the home 20 years ago and more tech is readily available.

He hopes to contribute to a better world, a place to leave to his children and grandchildren.