California Prepares for a Huge Solar Boom

Starting in 2020, California will become the first U.S. state to require almost all new homes to draw some power from the sun. The solar mandate is part of a wide-ranging push by the world’s fifth-largest economy to combat climate change by weaning itself off fossil fuels.

California already leads the U.S. in home solar panels. Solar makes up about one-seventh of its electricity supply, and that’s expected to grow for the state to meet its goal of 100% carbon-free power by 2045. Others may follow: Massachusetts is weighing a similar mandate, as is Maryland’s Montgomery County. “California has provided the template for a lot of U.S. clean energy policy,” says Hugh Bromley, an analyst for BloombergNEF.