California plans to generate 50 percent of its energy from renewable sources by 2030. The state is almost half way to this goal and making good progress. But sometimes these new power sources add more electricity than the state can use. Leia Guccione is with the nonprofit Rocky Mountain Institute.

Guccione: “California has seasonal variations in both how much energy customers want to use and how much energy the state generates.”

For example, moderate temperatures near the end of winter means less energy is needed. But a warm, wet spring can increase hydropower production.

Guccione: “You also start to have better solar output because of how the amount of daylight is changing in those months.”

New natural gas power plants are also contributing to the energy surplus. To keep from overloading its electrical grid, the state is selling – or in extreme cases – paying other states to take its excess energy.

As energy storage technologies improve, the hope is that California will be able to store its excess power for use when needed. That will be a major advance in the transition to a clean energy system.

Reporting credit: Mark Knapp/ChavoBart Digital Media.
Image graphic: Created by David McCarthy.