Our Electrifying World is a series about how electrification is creating a more sustainable energy transition. It is sponsored by Rewiring America.
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.)
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 networks, and therefore fewer electric homes. Finally, earlier models of heat pumps worked better in moderate climates, which meant there was greater adoption in the South. In recent years, there have been big innovations with cold climate heat pumps, which can deliver efficient heating even at outdoor temperatures as low as negative 22° Fahrenheit. This is why heat pumps are now being widely adopted in places with brutal winters like Maine and Colorado.
Maine has traditionally been oil dependent, yet it has rolled out heat pumps faster than the national average. Ten years ago, the state introduced a program encouraging heat pump installations. Since then, the number of homes using electricity for heat in Maine has tripled, from 28,050 in 2014 to 79,160 in 2023, according to Census Bureau data. Due to the Trump administration’s freezing of funds, a promised grant to Maine (and four other New England states) from the Environmental Protection Agency is uncertain. But even without that money, Maine will likely continue to roll out incentives for heat pumps.
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Our smart, bright, weekly newsletter is the uplift you’ve been looking for.Maine’s climate action plan, Maine Won’t Wait, signed into law by Governor Janet Mills in 2019, set a goal of installing 100,000 new heat pumps by 2025. The state achieved that goal in 2023 — two years ahead of schedule. At that point, Governor Mills unveiled a new target for the installation of 175,000 additional new heat pumps by 2027.
In Maine, heat pumps are a bipartisan affair. Former governor Paul LePage, a Republican, installed heat pumps at his official residence, the Blaine House, in 2014. He and his wife Anne were reportedly so impressed with the technology, that they later added heat pumps to their waterfront home in Boothbay, too. Low-income folks in rural areas — many of whom voted for Trump — prefer heat pumps because they don’t need to arrange a fuel delivery when they’re running low. (Some remote areas of the state never had gas lines installed.)
Mike Kelly, a project manager at an architectural engineering firm who lives with his wife in Falmouth, Maine, took advantage of state rebates a few years ago and purchased four Mitsubishi mini-split heat pumps for their two-story Cape Cod. “They work very, very well!” he says. This winter, there have been several days where it was in the negative single digits, and the heat pumps have kept their house cozy, Kelly says. He also loves that they become air conditioners in the summer. In fact, that’s one of the primary reasons they switched to heat pumps. “A lot of these older homes in New England didn’t have any air-conditioning put into them. But as things have now gotten a lot warmer in the summers here, we’re experiencing higher temperatures, higher humidity,” Kelly says.
Adopting heat pumps also saves money. According to Efficiency Maine, an agency that runs energy efficiency programs, replacing oil with electric heat pumps saves a household an average of $662 a year. Also, because no fuel is burned, there are never any oil or gas leaks. In Maine, nearly 70 percent of electricity is generated from renewable resources like hydroelectric dams, wind turbines and biomass fuels, so converting to heat pumps drastically reduces greenhouse gas emissions.
Last year, five New England states — Connecticut, Rhode Island, Maine, Massachusetts and New Hampshire — won a $450 million Climate Pollution Reduction Grant via Biden’s Inflation Reduction Act to accelerate the adoption of heat pumps. What was so unusual about the grant is that it wasn’t merely to extend rebates to homeowners, according to David Cash, the former regional administrator for the Environmental Protection Agency’s New England offices.
“It [the proposal] really looked at this from the whole supply chain perspective,” says Cash. Leaders in these states knew that in order for a roll-out of the technology to flourish, local mom-and-pop HVAC installers would need to be trained in heat pump technology and installation. Parts of the grant, therefore, were earmarked for workforce development and training workshops that included HVAC installers in all five states. Some of the funding was slated to go to technology innovations and improvements, according to Cash. Forty percent of the grant was also allocated for low-income communities, including rural folks who struggle to pay their high-cost oil bills. “It’s a fantastic program,” says Cash.
That said, these states currently can’t move forward as planned since the Trump administration has frozen these congressionally mandated funds. That’s a pity, says Cash, not just for regular residents of these states, but also for the small businesses all over New England that would install the heat pumps.
“What that means is that jobs are going to be lost,” explains Cash. “These are good blue-collar jobs of installing this technology all over New England, in rural areas and cities.” They are also jobs that can’t be outsourced or exported — local workers, by necessity, need to do the installations. “Peoples’ energy bills are going to increase. Bad air quality is going to spike because of this,” Cash says. He and others believe that this is all part of the Trump administration’s goal of hampering the development of clean energy at the behest of the fossil fuel industry.
Despite the frustrating delays, Cash says there’s no question in his mind that heat pumps will continue to roll out in New England and the rest of the country. “That’s the direction we’re going to ultimately go. It’s just a question of how the Trump administration is going to get in the way of that happening at the rate it should be happening.”
Pierce at Rewiring America agrees. The fact that states with no urgent climate commitment like Alabama and South Carolina have a high adoption of heat pumps shows their mass appeal. “I think this is a testament to the trans-partisan value proposition that these technologies offer in many different political contexts because of the bottom-line benefits to households,” Pierce says.
Cash sees Maine’s success as a clear sign for the future of heat pumps. “The win-win-win from this kind of effort — whether it’s on cost savings, emissions reductions, job growth, technology development — are huge,” he says. “This will happen. If this can happen in Northern Maine — where you get rid of these old stinky oil furnaces that are dirty and increase air pollution and replace them with these clean energy heat pumps that are now driven by increasing amounts of renewable energy? That’s a good news story.”
