Published by Bloomberg News: Nearly every home has a water heater, but people tend not to think about it until the shock of a cold shower signals its failure. To regulators, though, the ubiquitous household appliance is increasingly top of mind for the role it could play in reducing greenhouse gas emissions and weaning the power grid from fossil fuels.

Nationwide, about half of water heaters are powered by natural gas. In California, water heating is one of the biggest consumers of fossil fuels and gas water heaters account for 90% of the market. Swapping them for heat pump versions could reduce greenhouse gas emissions from water heating in the state by as much as 77%, according to a paper published in January by the nonprofit New Buildings Institute.

Inefficient conventional electric water heaters—which use an electric heating element—are common in regions of the U.S. That means those homes already have electrical panels capable of powering heat pumps, making a switch cheaper and quicker, according to Amruta Khanolkar, a project manager at the New Buildings Institute in Portland, Oregon.

She says that later this year three big makers of heat pump water heaters, General Electric Co., Rheem Manufacturing Co., and A.O. Smith Corp., are expected to introduce versions that can be plugged into standard 120-volt panels, eliminating the need for expensive electrical upgrades. (The trade-off is that such water heaters may not be suitable for colder climates.)

“We’re currently in a climate emergency and in a pandemic where people are working from home and using more energy for water heating,” says Khanolkar, who manages the Advanced Water Heating Initiative, a coalition of manufacturers, utilities, and government agencies. “The residential sector is now even more critical for decarbonization.”

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