Today, the electric grid in California is fairly clean and getting cleaner: in 2018, over 50% of electricity generated in-state came from carbon-free sources. A third of that was renewable, mostly solar and wind, with nearly 12% hydroelectric and close to 10% nuclear. The percentage of renewable energy continues to rise as California steps up to meet ambitious clean energy goals. Check out this report for more details on the energy mix of California’s grid .
Most of the clean solar on the grid is generated in the middle of the day. This is the cleanest time to use electricity. Scheduling appliances to operate at these times instead of in the evening or morning avoids running the dirtiest peaker plants and reduces the overall emissions from the electric grid. When the electricity supply exceeds demand, the grid operator cannot use all solar generation, leading to curtailment. At those times, the incremental emissions of using additional electricity are effectively zero. This is clearly shown by the marginal emissions profile for the electric grid in California in April 2019: from 7 am to 3 pm, using additional electricity was effectively carbon free!
Taking advantage of this cleaner electricity reduces home carbon footprints, helps utilities integrate more renewable energy on the grid, and keeps electric rates low for everyone. All critical to achieving a 100-percent carbon-free grid as quickly as possible.
To find out more on how renewable energy is transforming California’s electric grid, click here for an article on the “Duck Curve”.
* Curtailment is the reduction of output of a renewable energy resource below what it could have produced. This often occurs when energy supply exceeds user demand.
* Peaking power plants, also known as peaker plants, generally run only when there is a high demand, known as peak demand, for electricity.