Los Angeles Power and Water officials have struck a deal on the largest and cheapest solar + battery-storage project in the world, at prices that leave fossil fuels in the dust and may relegate nuclear power to the dustbin.

Later this month the LA Board of Water and Power Commissioners is expected to approve a 25-year contract that will serve 7 percent of the city’s electricity demand at 1.997¢/kwh for solar energy and 1.3¢ for power from batteries.

“This is the lowest solar-photovoltaic price in the United States,” said James Barner, the agency’s manager for strategic initiatives, “and it is the largest and lowest-cost solar and high-capacity battery-storage project in the U.S. and we believe in the world today. So this is, I believe, truly revolutionary in the industry.”

It’s half the estimated cost of power from a new natural gas plant.

Mark Z. Jacobson, the Stanford professor who developed roadmaps for transitioning 139 countries to 100 percent renewables, hailed the development on Twitter Friday, saying, “Goodnight #naturalgas, goodnight #coal, goodnight #nuclear.”

The nuclear critic Arnie Gundersen, who predicted storage prices under 2¢/kwh four years ago on the night Elon Musk unveiled the Tesla Powerpack, noted Saturday that his 2015 prediction was too high. He too said, “Goodbye coal, nukes, gas!”

Read more: Forbes