These heating and cooling systems, once considered useful only in warmer climates, have in the past few years become far more sophisticated. They are now the best chance we have to phase out fossil fuels as a means of heating and could set the stage for a climate policy revolution.
Demand is already skyrocketing in Europe, where surging gas prices due to the war in Ukraine have forced consumers to scramble for alternative home-heating strategies. In Germany, heat pump sales jumped 25 percent from 2021 to 2022. In Finland, they rose 80 percent.
The continent still has a long way to go before it can wean itself off Russian natural gas, but every newly installed heat pump is a step toward “electrifying everything,” as clean energy advocates put it.
Americans are not yet as enthusiastic, but policymakers in many states recognize heat pumps’ potential. A New York commission recently approved a plan to require all new houses built in the state after 2025 to use electric systems rather than those running on natural gas, oil or propane. After 2030, it seeks to require homeowners to replace all fossil-fuel-burning systems with non-carbon-emitting ones once they give out.
New York’s approach is the most aggressive in the country, but it’s by no means alone. Fifteen states and more than 100 cities have plans to encourage heat pump installation. The federal government is in on the strategy, too. The Inflation Reduction Act provides generous rebates and tax incentives for those who install the devices, and the Energy Department has dedicated $250 million to increase their production.
These efforts are well worth the expense. Consider that buildings consume about 40 percent of all energy in the United States. Residential buildings alone contribute to about 20 percent of U.S. carbon emissions, with half heated by burning fossil fuels.
Heat pumps, in contrast, simply move heat from the outside air or ground inside — even during frigid winter months.
To understand how this works, keep in mind one rule of physics: Heat always moves to cold. This is what makes air-conditioning work: It uses a gas known as a refrigerant, which it depressurizes to bring to a very cold temperature. (The same process explains why aerosol cans become cold when they’re sprayed.) The unit then moves the cold gas through a coiled pipe, which draws heat from a room.
Heat pumps use the same mechanism to cool homes in the summer. And in winter, they can reverse the process to provide heat.
The principle is the same, but rather than move heat outside, they move it into the house. What if it’s cold outside? It doesn’t matter. So long as the refrigerants are colder, they can draw heat inward — even in sub-zero temperatures. Mind-blowing, isn’t it?
It’s also extraordinarily efficient. For every unit of electricity a heat pump uses, it can generate 2.5 to 5.5 units of heat, according to the International Renewable Energy Agency. In other words, heat pumps have an energy efficiency of 250 to 550 percent. Fossil-fuel boilers, in contrast, are at best 95 percent efficient.
This is why heat pumps often save energy costs in the long term, even though they can be expensive to install, especially when replacing existing systems. Cost estimates vary widely depending on the size and age of a house, ranging from as low as $3,000 to upwards of $20,000.
Naturally, efforts to push consumers to embrace heat pumps have generated much anxiety on the right. Republicans in New York have panned their state’s plan as “radical” and claimed it will leave residents “in the dark and in the cold.” But policymakers must not flinch. Yes, retrofitting homes can be expensive. The answer is to offset the costs with subsidies, as many states are already doing.
Remember also that fixing home energy systems will be cheap compared with doing nothing. One analysis estimates that failing to address climate change will cost the U.S. economy $14.5 trillion over the next 50 years.
Some critics argue that expanded use of heat pumps will put extra stress on the electricity grid, which is powered in no small part by fossil fuels. This is fair, but not a reason to oppose them. The goal should be to adopt electric heating while simultaneously upgrading the grid to increase capacity and shifting generation to wind, solar, nuclear and other clean energy sources.
Of course, heat pumps alone won’t solve the climate crisis. But electrifying how we heat homes is a significant step toward solving the emissions puzzle. Government incentives can make that change faster.
