Workers from Horizon Homes install heat pumps at Homestead Village in Westbrook on Aug. 8. Derek Davis/Staff Photographer

FREEPORT — Maine’s quasi-state agency that promotes energy efficiency says the state is on track to reach its goals in electrifying buildings to reduce greenhouse gas emissions.

But a business owner at Efficiency Maine Trust’s annual event Thursday questioned a shift in a rebate program to incentivize electric pumps that heat an entire house, rather than a few rooms.

“We’ve been on a pretty good streak lately,” Executive Director Michael Stoddard told heating and cooling business owners and employees.

Heat pumps are “becoming a bigger and bigger part of the programs that we are operating at Efficiency Maine and a bigger and bigger part of what policymakers want to prioritize,” he said.

In July 2023, Maine surpassed its goal of installing 100,000 new heat pumps two years early. Gov. Janet Mills set a new target of installing another 175,000 heat pumps in Maine by 2027. Maine will receive between $45 million and $72 million from Washington to install heat pumps for home heating and cooling and hot water heaters.

Residential electric heat pumps benefit from Efficiency Maine rebates up to $8,000, depending on income, and federal tax credits of up to $2,600.

The Maine Climate Council has set a goal of 487,000 homes – 90% of single-family homes in Maine – that will meet their entire heating load with electric heat pumps in retrofits and new construction. “We are on that trajectory and the policymakers have told us we want you to keep going until you get this done,” Stoddard said.

The state’s Climate Action Plan has established an interim target of 115,000 homes entirely heated by heat pumps by 2030; about 20,000 homes are currently heated entirely with electric pumps.

Michele Putko, chief executive officer and founder of Clean Flame Thermal Solutions, a Cape Neddick business that combines heat pump technology with a fireplace, asked Efficiency Maine officials if whole-home heat pumps would be a harder sell. She cited higher costs and electricity outages that would entirely darken houses that depend on whole-home heat pumps.

“Many of us have concerns about power outages, the expense, all-or-nothing,” she said.

Stoddard said momentum for whole-home heat pumps, indicated by rebates, is not slowing but will require more marketing and education.

“It was a significant shift. It took a little while for people to get comfortable with it,” Stoddard said.

Efficiency Maine’s shift is at least partly intended to make electricity the primary home heat source and discourage a secondary use of oil or gas.