Heating buildings frequently relies on natural gas or heating oil, which is why the sector accounts for about 10% of global emissions today. Heat pumps will be the central technology used to cut heating’s climate impact, predicts Yannick Monschauer, an energy analyst at the International Energy Agency.
Heat pumps run using electricity from the grid. While fossil-fuel plants still help power grids around the world, renewables and low-carbon power sources also contribute. So with the current energy mix in all major markets, heat pump are better for the climate than directly fossil-fuel-powered heating, Monschauer says.
Heat pumps’ real climate superpower is their efficiency. Heat pumps today can reach 300% to 400% efficiency or even higher, meaning they’re putting out three to four times as much energy in the form of heat as they’re using in electricity. For a space heater, the theoretical maximum would be 100% efficiency, and the best models today reach around 95% efficiency.
The gulf in efficiency between heat pump and heaters comes down to how they work. Space heaters work by transforming energy from the form of electricity into another form, heat.
Heat pumps, on the other hand, aren’t turning electricity into heat—they’re using electricity to gather heat and move it around. It’s a subtle difference, but it basically means that a heat pump can return significantly more heat using the same amount of electricity.
A heat pump’s maximum efficiency will depend on the refrigerant and the system that’s installed, as well as the temperature difference between the room it’s heating and the outside.
