Over the past decade, California has become a globally acclaimed leader on renewable energy. Fueled by aggressive public policies, plummeting solar prices and evolving technology, the state has cut greenhouse gas emissions from its electric power supply in half since their 2008 peak, according to the California Air Resources Board.

“It’s really astounding how carbon dioxide emissions have been cut,” said Anthony Kovscek, chairman of the energy resources engineering department at Stanford University. “It’s been really remarkable how much renewable and solar we’ve been able to put on the grid and balance it.”