Heat pumps are having a surprisingly equitable moment in the spotlight.
Using electricity, heat pumps can both heat and cool homes. And according to new research, the appliances are now just as common in low-income households in the US as they are in wealthier homes. That pattern is unusual among consumer climate technologies, many of which are much more likely to be adopted by the wealthy.
Heating buildings is a huge climate problem—roughly 10% of global emissions come from our efforts to keep our indoor spaces comfortable. That’s why governments are eager for people to adopt new appliances like heat pumps that can run on electricity, which could help replace systems that burn fossil fuels.
But historically, changes that reduce emissions haven’t been distributed equally. In the US, the richest households are about five times more likely than low-income groups to have solar panels and about 10 times more likely to drive electric vehicles. Even lower-cost technologies like high-efficiency washing machines and LED lightbulbs are more likely to be used in higher-income homes.
Heat pumps don’t appear to follow that trend, according to the data from a 2020 survey on US household energy use, which was released in March 2023 by the US Energy Information Agency.
“I was just shocked when I saw this pattern,” says Lucas Davis, an energy economist at University of California, Berkeley, and the author of a June working paper analyzing the data. According to Davis’s analysis, roughly 15% of homes across income levels use heat pumps as a primary heating source.
These numbers reflect a significant jump in adoption by households with incomes under $20,000. About 7% of them used heat pumps in 2015, but 14% did in 2020, according to the EIA data. The level of adoption in wealthy homes stayed about the same over this period. The reasons for this pattern aren’t totally clear, though it could have to do with where new construction is taking place, Davis says.
Rather than income, factors like electricity prices and local climate are much more likely to influence whether a home has a heat pump. The appliances work more efficiently in warmer weather and are more common in states with milder winters, especially in the southeastern US. About 40% of homes in Alabama, South Carolina, and North Carolina use heat pumps.
Lower electricity prices—which make heat pumps less expensive to operate—also correlate with higher adoption. While heat pumps tend to have a high up-front cost, the combination of central air conditioning and a heating system can be even more expensive, making a combined system an economical choice even at the outset.
Ultimately, the analysis suggests there are some places where heat pumps are simply a cost-effective option today, Davis says. “I don’t think this is a choice that’s driven by ideology. I think it’s driven by dollars and cents.”
The same pattern may not play out elsewhere in the world, says Yannick Monschauer, an energy analyst at the International Energy Agency. There’s not much global data available today about which homes have heat pumps installed, Monschauer says, but some studies in Europe have documented higher uptake among higher-income households.
The up-front costs of heat pumps remain high and will continue to be a barrier in many parts of the world, especially when it comes to more expensive models that pull heat from the ground instead of the air, or for homes that need to be retrofitted with new technology, Monschauer says.
Incentives like rebates and tax credits will be key in pushing heat pump adoption outside the narrow band of conditions where the appliances are already the most economical option, Monschauer says, in particular for lower-income households. Over 30 countries around the world have incentives in place, and new US programs could help even more homes use the devices to cut emissions and energy costs.
The Inflation Reduction Act, passed in the US last year, includes federal tax credits of up to $2,000 for taxpayers installing heat pumps. And rebate programs can include funding of up to $8,000 per household, depending on the state.
How those incentives might change the distribution of heat pumps across the country remains to be seen. The fraction of homes that rely on them overall is still small, and there’s no guarantee that they will continue to be adopted at equal rates by households with different incomes. But researchers like Davis see the potential for incentives to continue bringing the cost savings and climate progress associated with heat pumps to everyone, not just the rich.
“At least in the US, it has the potential to be really widely adopted, by a lot of different people,” he says. “There’s an egalitarian something about it.”