Air-source heat pumps are gaining traction in Maine. In 2019, Gov. Janet Mills set a goal to install 100,000 units — in homes, businesses and public buildings — by 2025, along with enhanced rebates through Efficiency Maine and a low-income heat pump program at MaineHousing.

The target was exceeded two years early with 104,000 installations. About half of the goal to install 15,000 heat pumps in low-income households by 2025 was reached by November 2023.

The state’s new target is 175,000 more heat pumps by 2027. If achieved, Maine would have over 320,000 heat pumps in total.