In 2021, 35.8% of California’s electrical energy was generated from natural gas. The chart below was compiled from data on the California Independent System Operator’s website. This website has a wealth of data available and shows what is happening now on the grid and in the past. During daylight hours a large part of the electrical grid is generated by solar and wind. But when the sun goes down, natural gas must come online to keep everything humming. At times during sunny afternoons, there is so much electricity coming from solar that there is an over-supply and has no value in some locations. Large scale energy storage is going to be key in reducing this contribution from natural gas. A YouTube video put together by Physics Girl describes the various methods to store large scale energy. By large scale energy we are talking about storage power plants that can put out 100 megawatts or more for an extended time. One method that is particularly intriguing is Thermal Batteries. This could be relatively lower cost but is years away. There is a local (Sunnyvale CA) startup company Antora Energy that is working on this.