The latest numbers for the library HVAC system are in, and the estimated price tag for the decarbonization option with a ground-source heat pump (GSHP) system has gone up by $1.2 million since January. However, the cost to the town would be only about $373,000 more than a conventional gas-fired full replacement system if tax incentives and grants are factored in.
Replacing only the gas-fired boiler would cost about $330,000, though the rest of the HVAC system is near the end of its life as well, officials say.
The GSHP option is now estimated to cost a total of $6.25 million, partially offset by $2.55 million in anticipated incentives and grants, including a $1 million grant already approved, resulting in a net cost of about $3.70 million, vs. an updated estimate of $3.32 million for a conventional system. “Because this option does not receive the same decarbonization incentives, the gross and net project costs are effectively the same,” Assistant Town Administrator Dan Pereira wrote in a Sept. 11 memo that the Select Board discussed last week.
“While the town expects to receive additional incentives under the Eversource/MassSave program, the value of those incentives will not be known until the town undertakes further technical analysis with Eversource,” he added.
When it comes to energy use and emissions, the GSHP option clearly wins out. “Compared with the actual utility baseline, the ground source heat pump option is projected to reduce total annual energy use by approximately 657 MMBtu [million British thermal units]. By comparison, the conventional replacement option is projected to reduce total annual energy use by approximately 104 MMBtu,” according to Pereira’s memo.
The ground source heat pump option would also eliminate on-site natural gas use for the library HVAC system. “As a result, when compared against actual utility baseline, the ground source heat pump option projects annual greenhouse gas emissions reductions of approximately 32 metric tons of CO₂e [carbon dioxide equivalent], compared with approximately 8 metric tons of CO₂e for the conventional option,” the memo says.
Board member Jim Hutchinson noted that there would probably be only a small savings in annual operating costs for the GSHP option. “We need to know the difference between the operating cost of the current system and a new one,” he said. “If we’re going for sustainability, that’s an obvious win,” though not necessarily for operating costs.
Multiboard meeting
There will be a multiboard meeting on Monday, Sept. 28 at 6:30pm to discuss the issue in advance of the Oct. 24 Special Town Meeting where residents will be asked to choose one of the options. The Select Board expects to get more information from the Finance Committee and possibly the Green Energy Committee on energy usage for the two systems.
The town originally planned to have a vote at Annual Town Meeting in March 2026 on the two options, but the motions were tabled after officials found that the expected tax incentive estimates were “too optimistic.” But as of this week, “that’s an area we feel much more confident about,” Town Administrator Tim Higgins said.
If voters opt for the ground source heat pump system, the additional $1.2 million would come from some combination of the town’s stabilization fund and Community Preservation Act funds. The CPA fund was already expected to bear the cost so as to avoid a tax increase.
