When leaders of the Concord Quaker meetinghouse replaced their old boiler with a geothermal heat pump, they were excited about operational benefits and with helping out the climate. But the best part, it turns out, is all the little kids.

“This is exactly what we wanted,” said David Woolpert, who has been a member of the Quaker group, known as a meeting, for four decades.

Since the installation of the geothermal system last fall, the one-story meetinghouse, built in 2010, has hosted Pathfinder Natural Learning Center, an outdoor-oriented children’s program. That not only makes use of the building during the week and brings in a little rental income but also fills the space with the energy of the preschool set.

The meeting had long wanted a connection with a children’s program – before moving over the border to their home in Canterbury they were a tenant at Merrimack Valley Day Care Center in Concord – but the old heating system burned wood chips. Under safety codes that meant the meetinghouse couldn’t host a school without spending $10,000 or more on fire-prevention work, including installing lots of sheetrock.

“We said if we’re going to spend $10,000, how about putting in a new heating system … since we knew the boiler would probably have to be replaced in five years,” Woolpert said.

The geothermal heat pump is powered by electricity. It sends refrigerant down one 400-foot well and back up another one, using the stable underground temperature to reduce the amount of energy needed to heat or cool the space through a piping system in the floor.

Geothermal is much more efficient than systems that burn fuels or older resistance electric heating systems. Ground-sourced geothermal is even more efficient than air-sourced heat pumps but the latter are much more common, and much less expensive to install.

Overall the changes at the meetinghouse cost about $60,000. The switch was made financially tenable by the federal Inflation Reduction Act, which expanded a 30% tax incentive on energy-saving systems from private businesses to include non-profits. Fund-raising and grants also helped.

From a climate point of view the switch from a pellet boiler is a particularly big benefit because the meetinghouse has 16 kilowatts of solar panels on the roof. These generate at least four times more electricity than the building used previously, power that is shared with a number of homeowners under a system known as a power purchase agreement. Even with the geothermal system, Woolpert said the solar panels should produce twice the building’s electricity needs over the course of the year, meaning the meeting can now say they are truly carbon-neutral.

Another benefit is that the building can now hold groups larger than the previous fire-safety limit of 49 people. The meeting took advantage of that in a recent fund-raiser that drew some 75 people. And because their mechanical room no longer has the specialized bin holding a ton of pellets, they’ve got more space for storage.

Another plus: They also don’t have to clean out the furnace every week. “We bought what was a new model (of furnace) at the time and six months later they came out with a model that was self-cleaning,” said Woolpert.