In California, natural gas helps balance changes in electricity demand and solar output

In California wholesale electricity markets, natural gas-fired electricity generation helps to balance fluctuations in electricity demand with daily cycles in solar-powered electricity generation. Natural gas and solar are the two most prevalent sources of electricity generation in California; however, solar generation is non-dispatchable. Grid operators in the state use natural gas and, to a lesser extent, hydroelectricity and electricity imports from neighboring areas to balance changes in electricity demand.

source https://www.eia.gov/todayinenergy/detail.php?id=46236