Tag Archives: Regional Transmission Grid

Too Much Solar in California? Not If You Bottle It

By Lauren Sommer, KQED

The cost of solar power has plummeted in recent years, which has led to a renewable energy boom in California.

But there’s a big hang-up: solar energy doesn’t provide a 24-hour supply. When the sun sets, the power from solar farms drops off, just as California needs it most. That’s sparked new interest in technology that stores electricity. And the energy storage technology race is going far beyond your typical battery.

Solar Peaking

“Pretty much everyday, we hit peak output,” says Michael Wheeler, a vice president at Recurrent Energy in San Francisco, looking at a screen showing the solar farms his company manages. But earlier this spring, something happened that, at first, doesn’t seem to make sense.

It was the middle of the day, when one of the solar farms was cranking out electricity, and his company got a message. There was too much electricity on the grid. The electric grid managers were telling solar farms to shut down. “The project went from almost peak output to zero for about two hours,” he says.

This happens on sunny, spring days when there is plenty of solar power but Californians aren’t using a lot of air conditioning yet, so demand for power is low. The solar and wind power comes in on top of what natural gas power plants are generating. Because renewable energy production goes up and down with passing clouds and wind conditions, grid operators say they need the continuous supply from natural gas to make up for those fluctuations.

Shutting down natural gas would leave the power supply less stable. Many gas plants can take between four and eight hours to restart, once they’re turned off. As more solar farms come online, the pressure to shut them down on mild, sunny days is only expected to become greater. California plans to get 50 percent of its electricity from renewable sources by 2030.

Read full article from KQED

Related article: What will California do with too much solar? (KQED) – April 4, 2016