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Battery Power Sell-Off Preceded Early September Blackout Warning

In the hours before Californians were told to cut back or face blackouts on Sept. 6, the state’s grid operator allowed much of the backup battery power supplies to be sold off to the highest bidder, according to data reviewed by NBC Bay Area’s Investigative Unit.

Data from the California Independent Systems Operator, Cal ISO, reveals that beginning at 1:30 p.m. on Sept. 6, battery power providers began to sell their stored electricity as the state was about to enter a Stage 2 emergency due to extreme heat and high demand.

As prices soared to $2,000 per megawatt hour that afternoon, the data shows about 30% of the state’s battery daily storage capacity was sold off, enough to power an estimated 3 million households for an hour.

The drawdown continued until late in the day until less than an hour before Cal ISO issued a text alert, urging customers to conserve to avoid blackouts.

“Everyone knows that we need batteries in the evening instead of the middle of the day, said Tyson Siegele, an energy analyst with the Protect Our Communities Foundation ratepayer group. “So the market really should have been designed properly for this particular scenario prior to hitting Sept. 6.”

CAISO CEO Elliot Mainzer said the battery suppliers were simply responding to the market.

“They want to store energy when prices are relatively cheap and they want to sell it and maximize their value when prices are really high,” he said.

But Elliot Mainzer acknowledged the sell-off left supplies so depleted that CAISO had to intervene, issuing a series of what are called “exceptional dispatches” – emergency orders to battery power suppliers, telling some them to stop selling reserves needed for when the sun goes down.

In the end, four battery suppliers capable of providing 330 megawatts were instructed to stop selling power at about 4:30 p.m. on Sept. 6, according to a statement issued by Cal ISO. Operator data shows battery supplies were held back starting just after 5 p.m., before ramping up again as the sun went down.

The orders came too late to avoid system operators having to make the last-minute plea for conservation, however.

“We’re just grateful to all the people in California, including electricity consumers, who, at the end of the day stepped up,” Mainzer said.

Over the two following days, grid operators intervened with more exceptional dispatch orders to battery power suppliers a total of 26 times, Cal ISO said in a statement.

“The ISO has established a very open and collaborative working relationship with the battery storage industry,’’ the statement noted, adding that “we will continue to evolve and refine our market rules based on these and other learnings to best leverage the flexible capabilities of the battery storage fleet and align market price signals with the reliability needs of the grid to the maximum extent possible.”

But the head of the California Energy Storage Alliance said that no changes are needed because the system met the challenge.

“I don’t think it really means that this storage (fleet) was doing anything wrong,’’ said Alex Morris, whose alliance represents battery power suppliers. “It was just seeing prices that were so significant during the day.”

Morris said the battery power system stepped up and worked with grid operators to assure the state could meet historic demand when “there was no room for error.” But Siegele said the scramble could have been avoided, had CAISO acted beforehand to prevent the near meltdown. He warned that Cal ISO still hasn’t done enough to protect Californians during the next big heatwave.

“There is a real safety issue when you have markets that are incentivizing the incorrect usage of batteries” he said, given the risk of blackouts. “Blackouts are absolutely life safety issues.”

Cal ISO said while its conducting a “comprehensive retrospective analysis’’ of what happened, “in general, our system operators were very pleased with the performance and availability of the 3,600 MW battery fleet during the course of the heat event.”


Source: NBC Bay Area

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