Versant Power is pushing back against a new approach to broaden the use of heat pumps, which already are a key part of Maine’s toolbox to cut greenhouse gas emissions.

Efficiency Maine Trust, a quasi-state agency that promotes energy efficiency, has shifted its rebate program to incentivize electric pumps that heat an entire house rather than one or two rooms. Its intent is to make electricity the primary home heat source and discourage the secondary use of oil or gas.

An outdoor heat pump unit at a South Portland home last December. Brianna Soukup/Staff Photographer

Michael Stoddard, executive director of Efficiency Maine Trust, said one reason for the change is that a federal tax credit of up to $2,000 for a single heat pump is significantly more than the $400 and $800 that Maine once offered as an incentive. In addition, an analysis showed that a heat pump does not operate frequently when a boiler also is running, he said.

Stoddard said a heat pump competes with a boiler that is a bigger and more powerful system, “forcing the heat pump in a standby role.”

“As a result the customer is not saving very much money,” he said.

Moving to a whole-house heat pump allows a homeowner to double down on heat pumps and turn off the boiler, he said.


Versant challenged the proposal in a filing with the Public Utilities Commission, saying that federal tax credits are not sufficient in “amount or timing of support” for customer-installed heat pumps because tax credits require customers to pay upfront.

Versant, which serves 165,000 customers in northern and central parts of Maine, said a shift to whole-home heat pumps “risks shifting greater access to higher-income households who can afford the more extensive retrofits to their home.” The utility is concerned the shift will benefit wealthy homeowners and large-scale developers, said David Littell, an attorney and former PUC member who worked on Versant’s filing.

Stoddard called that argument “baloney.” Participation since Efficiency Maine introduced whole-house heat pumps several months ago has been strong among predominantly moderate- and low-income customers. he said.

Low-income customers can receive 80% of a project’s cost up to an $8,000 rebate, those with moderate incomes are eligible for 60% of a project’s cost up to a $6,000 rebate and any income may be reimbursed 40% of cost up to a $4,000 rebate.

The pumps extract heat from outdoor air or from underground and transfer it inside, instead of heating up a coil in a furnace. They also cool interiors by pulling heat from indoors and transferring it to outside or underground.

Versant says landlords have little incentive to reduce tenant energy costs and will likely be reluctant to install whole-home heat pumps.


“Do customers make the decision on what heat they turn on or off?” Littell asked. “Customers are in the best position to make that decision.”

Versant has long supported electric heat pumps and insists that Efficiency Maine “not abandon” a one- or two-room system, Littell said.

Eben Perkins, chief strategy officer at Competitive Energy Services, a Portland energy consulting firm, said Efficiency Maine’s transition to whole-home heat pump systems “makes good sense.”

“This a proven solution for providing reliable heating throughout a Maine winter and the simple truth is that we won’t be able to meet Maine’s emissions reduction goals without significantly scaling up to whole-home installations in the coming years.”

Gov. Janet Mills announced in September that Maine has surpassed its goal of installing 100,000 heat pumps by 2025, two years ahead of schedule. She set an updated target of installing 175,000 more heat pumps in Maine by 2027.

Stoddard said it helps explain why Efficiency Maine shifted to a whole-home standard. “It’s clearly the most effective way of reducing carbon emissions in the home,” he said. “We need to transition from just putting in a single heat pump and be partial to a holistic heating system. That contributed to our thinking and our shift.”

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