As Los Angeles weans itself off the last of its coal-generated electricity, the city needs to replace that fuel with a climate-polluting natural gas plant in Utah, Los Angeles Department of Water and Power staff insisted Tuesday. But they also pledged the facility would eventually burn renewable hydrogen instead of natural gas — something that has never been done before.

Following pressure from climate change activists, DWP laid out its most detailed timeline yet for transitioning from planet-warming gas to clean-burning hydrogen at a new facility that would replace the coal-fired Intermountain Power Plant. If the utility succeeds, the Intermountain plant could become a model for governments and power companies around the world.

“There is no way to get to 100% renewable energy that I can see right now without hydrogen in the mix. It doesn’t exist,” DWP General Manager Marty Adams told the utility’s board of commissioners on Tuesday.

Utility staff told the board it’s critical to build an 840-megawatt gas-fired power plant to replace the coal-burning facility that DWP operates today. Without a traditional power plant, they said, the city might have trouble keeping the lights on when there’s insufficient electricity being generated by solar panels and wind turbines.

But for the first time, DWP leadership committed to installing turbines capable of burning a mix of 30% hydrogen and 70% gas when the new power plant opens in 2025. Under the timeline described Tuesday, that ratio would steadily change until the plant burns 100% hydrogen in 2045, the deadline set by state lawmakers for a 100% climate-friendly electricity supply.

“We will do everything we can to accelerate this,” Adams said.