U.S. utilities are increasingly exploring the use of what is called green hydrogen made from wind and solar energy to reduce emissions from power plants and pipelines. The early investments by companies including NextEra Energy Inc. and Dominion Energy Inc. are expected to help commercialize a costly technology that has been slow to develop despite its ability to provide a steady source of carbon-free power. Utilities and policy makers are beginning to view the technology as necessary to support ambitious renewable-energy goals.

The Los Angeles Department of Water and Power, the nation’s largest municipal utility, is spearheading a $1.9 billion effort to convert a coal-fired power plant in Utah to run on natural gas and hydrogen produced with excess wind and solar power. The plant, which serves numerous small utilities and electric cooperatives, has long been one of Southern California’s most significant power sources.

The gas turbines, slated for completion in 2025, will initially burn a 30% hydrogen fuel mix. Within two decades, they are expected to run entirely on hydrogen to comply with a California law that requires the state’s electricity supplies to be carbon-free by 2045.

“From a cost perspective, it doesn’t compete with natural gas at this point,” said Paul Schultz, director of external energy resources for LADWP. But he said the utility considers the conversion a long-term investment in changes that lawmakers and regulators are requiring.

And the price of green hydrogen is expected to become more competitive in coming years.

“The costs are going to go one direction, and that’s down,” said Craig Wagstaff, Dominion Energy’s senior vice president for Western gas distribution. “It’s just a question of how far down they’re going to go.”

Hydrogen, which is used in a range of industries, is most often produced from coal or natural gas through carbon-emitting processes. The production of green hydrogen, on the other hand, eliminates those emissions by using renewable energy to strip hydrogen atoms from water molecules through a process called electrolysis. Currently, only 1% of the hydrogen produced is green hydrogen.