Electric heat pumps, one of the most energy-efficient ways to heat and cool homes, perform a feat of seeming magic. In the winter, they extract heat from the outside air (even when it’s below zero), run it through a compressor, and then pump it indoors. During the balmy days of summer, a heat pump reverses this technology, essentially turning the heater into an air conditioner. (To do this it pulls heat from inside a building and releases it outside, leaving indoor spaces cooler.)

If that’s not awesome enough, electric heat pumps are also safer for human health than fossil-fuel-burning furnaces. In addition to contributing to global warming, these older technologies also release smog-forming nitrogen oxides and fine particulate matter that increase the risk of heart attack, asthma and many other health issues. Finally, heat pumps, once they are installed, result in lower energy bills. 

The U.S. has jumped on the heat pump bandwagon: In 2024, heat pumps outsold gas furnaces for the third year in a row — by 27 percent. 

And even though the Trump administration had, at press time, frozen former President Biden’s Inflation Reduction Act funding for all kinds of home electrification efforts including rebate programs and grants, states are still forging ahead — especially when it comes to heat pumps. 

“We’re quite optimistic and excited about the trends that we’re seeing for heat pump adoption, irrespective of federal support or engagement,” says Zach Pierce, director of state and local policy for Rewiring America, a nonprofit that promotes electrification. (Rewiring America sponsors Reasons to be Cheerful’s Our Electrifying World series.) “We’re seeing really exciting growth of the market, due to the bottom-line benefits that folks are seeing in reduced bills, improved comfort and improved safety of their homes.” 

In 2023, the U.S. Climate Alliance, a bipartisan coalition of 25 governors representing about 60 percent of the U.S. economy (and 55 percent of its population), made a commitment to quadruple heat pump installations by 2030. In 2024, nine states and the District of Columbia made a pledge to have heat pumps meet at least 65 percent of residential-scale heating, air conditioning and water heating shipments by 2030 and 90 percent by 2040. This ambitious goal, which was signed as a Memo of Understanding with the Northeast States for Coordinated Air Use Management (NESCAUM), serves as an example for other states to follow. (The nine state signatories are California, Colorado, Maine, Maryland, Massachusetts, New Jersey, New York, Oregon, Rhode Island — plus the District of Columbia.)

In the winter, heat pumps extract heat from the outside air (even when it’s below zero), run it through a compressor, and then pump it indoors. During the balmy days of summer, a heat pump reverses this technology, essentially turning the heater into an air conditioner.

Surprisingly, the states with the highest penetration of residential heat pumps are not known for leadership in the fight against climate change. According to the most recent data from the U.S. Energy Information Administration, these states are Alabama, North Carolina and South Carolina. As of 2020, more than 40 percent of the homes in these three states had heat pumps. Compare that to California, where only five percent of homes in 2020 used heat pumps. 

“Some of this is a legacy of cheap electricity prices, especially as it relates to the price of gas,” says Pierce. This is part of why the South is more dependent on electricity than other parts of the country. At the same time, states with pre-World War II housing stock tend to have legacy oil or gas distribution network