Many climate experts say the long-term solution is to replace most of those fossil-fuel appliances with electric versions powered by a greener grid. But in practice, that’s difficult. While cities like Berkeley have rewritten building codes to ban new buildings from using gas, more than a dozen mostly red states have passed laws explicitly forbidding cities from doing so. And that still leaves the question of what to do about millions of existing homes.
Stephen Pantano, the chief research officer at CLASP, said that encouraging people to install heat pumps when they’re going to buy central air-conditioners anyway could be a less intrusive way to start electrifying heating. “We found that a relatively small investment of around $3 billion to $12 billion nationwide could have a big impact on energy use,” he said of the group’s new proposal. “It’s hard to find many ideas with that much bang for the buck.”
An even more drastic strategy, he added, would be to figure out how to replace more gas furnaces with heat pumps, so that the heat pump handles virtually all the heating and cooling. But that could require larger heat pumps for many homes or additional electrical upgrades and other retrofits. His group’s proposal for simply swapping out air-conditioners is a more modest first step.
Berkeley, which pioneered the idea of banning gas in new buildings, is now considering this approach. Only 10 percent of the city’s homes currently have air-conditioning, but officials estimate that fraction could triple in the hotter decades ahead. “Berkeley should work with A/C installers and heat pump manufacturers to ensure these homes install heat pump systems instead,” officials wrote in a recent draft strategy for electrifying existing homes.
“It’s a great idea,” said Jigar Shah, who directs the Department of Energy’s loan programs office. His office is exploring ways to help low-income Americans adopt technologies like heat pumps. “Heat pumps aren’t some untested technology,” he said. “We’re really in a place where it’s time to scale this up.”
Others were more cautious. “There are places where electrification may be beneficial, and places where it might not, and there are a lot of details that need to be worked out,” said Francis Dietz, a spokesman for the Air-Conditioning, Heating & Refrigeration Institute, an industry trade group. If more homes relied on heat pumps instead of gas furnaces, for instance, that could put a strain on electric grids in the winter, especially in colder parts of the country, he said.
There are other obstacles, too: Many Americans still aren’t familiar with heat pumps, and some have had bad experiences with older models that didn’t work as well in cold weather. While heat pump technology has improved significantly in the past decade, many contractors remain wary of them. And, of course, the name “heat pump” doesn’t sound like a device you want to install when it’s sweltering out.