How A California Utility Used A Battery To Jumpstart A Power Plant

Jan. 23, 2018
The Imperial Irrigation District (IID) performed the first “black start” of a power plant in North America.

Music fans traveling northwest on highway 86 toward the Coachella music festival next year might not give the rolling hills of California’s Imperial Valley more than a passing glance. But energy insiders know it as the site of a major technological feat that could herald a new era in power-grid resiliency.

In May, the Imperial Irrigation District (IID) performed the first “black start” of a power plant in North America. They did it by starting and revving up the El Centro power station to full power with only a GE battery energy storage system.

Why does it matter? Utilities that derive a lot of their power from renewable sources — as is common in California — typically keep gas and coal-fired thermal power plants running on standby to pick up the slack when the sun isn’t shining or the wind stops blowing. Along the way, they generate emissions and burn expensive fuel.

But the 33-megawatt grid-scale battery storage system in the Imperial Valley gives the IID enough energy capacity to power up to 44,000 homes and shut these plants down and supply electricity as needed.

That’s not all. Utilities typically rely on diesel or gas generators to bring the idled power plants back online, a solution that taxes both the budget and the environment. It turns out the battery, along with data and software, can also restart the power plant. “With the Imperial Valley battery storage system, we are definitely leaving behind the earlier stages of stand-alone grid battery storage,” says Mirko Molinari, general manager of distributed grid systems at GE Power. “We are now deploying systems in which the battery itself is just a commodity assigned to a routine job.”

Molinari says that while the battery is still a critical component, most of the value comes from “the sophisticated higher-level hardware and software.”

For the “black start,” for example, plant operators used data and GE software to make sure that the voltage, phase and frequency from the storage system’s batteries matched the power on the grid. This process called synchronization allowed them to restore power evenly and safely. Then, as the plant came back online, it recharged the battery.

Molinari says that batteries could also help reduce power failures in the future, or at least make them easier and cheaper to fix.

“The speed and flexibility required by today’s energy generation makes it enormously complex,” Molinari says. “It’s extremely difficult to determine exactly how much power is needed at a particular moment.”

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