The blistering heat waves punishing the Californian state require battery backup support for electricity grids to prevent blackouts. Unfortunately, the batteries kick in at a critical juncture when it is not needed.
Batteries help ins storing energy generated by hydropower or solar, and they help cushion when renewable energy sources are low. The electricity grid uses the price mechanism to trigger the batteries instead of demand levels. This led to mismatches, and on Tuesday, it happened exactly like that when the state avoided a significant outage and declared a grid emergency.
During the afternoon, the batteries started discharging when sufficient solar and other power supplies were available to cater to the demand. The cushion got depleted during the early evening when needed; the state was on the brink of a collapse. The blackout was averted thanks to the timely warning on mobile phone alerts to Californians.
Though the crisis was averted on Tuesday, the battery situation reveals a more significant issue with the grid, and it could soon exacerbate the outage issue until risks are resolved.
Battery Mismatch
According to Cody Hill, Senior Vice President at Rev Renewables, the battery deployment at an early stage was linked to the market signals. Hill, who looks after the battery and storage systems, informed that the California power market is set up in a manner that the energy storage system has to supply when called by the Grid operator the moment the wholesale price of power hits a cap of $1000 per megawatt hour.
The high demand on the grid on Tuesday afternoon because of the high heat led to the price cap getting breached and calls for pressing the batteries into service.
The California Independent System Operator, who looks after the state grid, did not respond to the request for comments.
The bright spot was that despite the problems, the batteries still managed to provide 2,700 megawatts of electricity supply. This was more than two-thirds of the total capacity and during the period 6 pm to 7 pm when maximum power was needed.
However, to avoid future mismatches, California will need to rework its owner market signals for increasing battery fleets.
