This plan is rather misleading. You're buying energy from the same grid, but paying a markup to say it's coming from solar and wind. Say the company generates 100Wh of solar, 100Wh of wind and 200Wh of natural gas. Bill buys the 50/50 solar and wind plan and "buys" 100Wh of solar and 100Wh of wind at a marked up rate. Charlie buys the normal plan and gets his energy from the remaining sources. If a meteor hits the gas plant at night, Bill's electricity is still going out.

California still generates 45% of its energy from fossil fuels. And another 10% from nuclear which some don't consider renewable. Solar and wind account for 21% of electricity generation: https://www.energy.ca.gov/data-reports/energy-almanac/califo....