ATTLEBORO — Last week, when nighttime temperatures plunged to about 10 degrees, it was much warmer underground — way underground.
At a depth of about 460 feet it was about 55 degrees, and that’s the way it always is.
That fact is helping property owners across the nation lower their energy bills in the winter and summer, which is exactly the goal of the Attleboro Housing Authority. It has embarked on a geothermal green energy project for its 59-unit Rivercourt apartment building on Hodges Street.
The U.S. Environmental Protection Agency estimates that as many as 1 million American homes use “ground source heat pumps” to supplement both heating and cooling needs. The pumps use the earth’s natural heat to bring warmth into a building in the winter and remove it in the summer.
AHA Executive Director Paul Dumouchel, who’s headed up the authority since October 2018, said the state-funded $5.5 million project has been in the planning stages for at least three years and finally got underway in December.
It’s scheduled to be done in January of next year.
When that happens, the earth’s natural warmth, a renewable energy source, will be pumped into the building’s heating system which, will reduce the energy, in this case electricity, needed to warm or cool the water used in the heating and cooling system.
The project involves the digging of 20 wells, each 460 feet deep, on AHA property.
Water is piped into those wells where it’s warmed to about 55 degrees and then back into a series of other pipes at a shallower depth. It then goes into the building’s heating and cooling system.
The earth’s warmth will reduce the building’s electric bills and cut into the amount of electricity National Grid needs to produce, which in turn lowers the amount of oil or natural gas the company needs to burn to create electricity.
Ultimately, it helps reduce what is referred to as the nation’s carbon footprint, or the amount of carbon dioxide released into the atmosphere when fossil fuels are burned. Most scientists blame carbon emissions for global warming.
Dumouchel estimated it will take about eight to 10 years to recover through lower electricity use the $5.5 million needed for the project.
And ultimately, less money spent on electricity means there’ll be more money to spend on other resident needs, he said.
“The savings can be applied to other areas of operation, which is always good for the residents,” Dumouchel said.
He said the building, which serves seniors and disabled citizens, is kept at 72 degrees during the winter.
North Attleboro resident John Donato, a project manager in the construction industry for many years, supervises the job for the AHA as clerk-of-the-works.
He said residents are kept informed about its progress through regular notices.
Contractors are J.J. Cardosi Inc., out of Riverside, R.I., and Gap Mountain Drilling out of Northfield, N.H., which specializes in geothermal well drilling.
Helene Karl Architects of Groton designed the project.