Big batteries flex their muscles, hit new records in evening peaks in Australia and California

Big batteries continue to grow their influence in key electricity markets in Australia and in California, with new records being set in both grids as the transition from baseload to variable renewables gathers pace.

In Australia’s main grid, known as the National Electricity Market, a new battery output record of 1,531 MW was set at 6.20pm (AEST) on Wednesday, May 21, according to Geoff Eldridge, from GPE NEMLog.

This was just 23 MW above the previous peak set a weak earlier, but virtually double its record 19 months ago of 784.3 MW, reflecting the big rush of new battery storage projects joining the grid.

Australia may have installed the first big battery in the world, at Hornsdale in South Australia in 2017, but it has long been overtaken in terms of sheer capacity.

California and Texas now lead the world, and in California, according to Grid Status, the output of battery storage broke through the 10 gigawatt (10,000 megawatts) barrier for the first time on May 20, at 7.20 pm local time.

Big batteries regularly account for more than 30 per cent of the supply in California’s evening peaks, and are often the biggest source of power.

South Australia has also reached occasions where big batteries account for 31 per cent of the supply in evening peaks, and this will happen more often with another two big batteries newly connected to the grid and working through their commissioning, and another six under construction in the state.

On Wednesday, Eldridge notes, the surge in battery storage across the NEM came as solar and rooftop PV wound down for the day, and the demand surge from heating and home appliances ramped up.

“While the NEM’s battery capacity remains smaller (than California), similar patterns are beginning to take shape as more storage enters the market and battery flexibility becomes increasingly important in balancing early-day and late-day demand,” Eldridge writes on a LinkedIn post.

These developments suggest the shift is well underway — and batteries have become a regular part of how the NEM responds to volatility and manages the evening peak.