Last spring, Elon Musk made a daring bet. He claimed he could build and install the world’s largest grid storage battery in South Australia within 100 days of the date a contract was signed or the system would be free. The contract was signed on September 29. Installation was completed by the third week of November. On December 2, the giant 129 MWh system was activated.
On December 14, the Loy Yang coal power plant — one of the largest in Australia — suddenly went offline. In an instant, the grid shed 560 MW of electricity, enough to power 170,000 homes. 600 miles away, the Hornsdale Power Reserve battery system, as the Tesla system is officially known, kicked in within 140 milliseconds. It reacted so quickly, in fact, that the local grid operator was unable to measure the response time accurately. 100 MW of power suddenly surged into the grid, buying valuable time for other power sources to come to the rescue. Utility customers were largely unaware that anything unusual had happened. That’s how good grid batteries work.
State energy minister Tom Koutsantonis told local radio station 5AA afterwards, “That’s a record and the national operators were shocked at how quickly and efficiently the battery was able to deliver this type of energy into the market. Until now, if we got a call to turn on our emergency generators it would take us 10 to 15 minutes to get them fired up and operating which is a record time compared to other generators,” Mr Koutsantonis said according to the Financial Review.
This is actually a benefit of grid-storage batteries that we highlighted years ago after touring the Younicos facility in Berlin. Here are a couple of telling charts from that visit that not only highlight how quickly batteries can respond, but also how cleanly they match the needs.
Back to the Tesla story: Just two weeks after the battery saved the day on December 14, the grid was disrupted by a power plant breakdown again. Another unit of the Loy Yang plant went offline unexpectedly, depriving the grid of 353 MW of power. Once again, the Tesla battery took mere milliseconds to send 16 MW to the grid.
Why aren’t more battery storage facilities being installed? Projects like the Hornsdale Power Reserve are not meant to supply power to the grid for hours on end. According to Quartz, it can power up to 30,000 homes, but 70 MW of the system’s 100 MW can only last for 10 minutes. The other 30 MW can provide three hours of power. In both instances, the generating station under contract to supply backup power to the grid was the Gladstone Power Station — another coal powered facility.
It would be inaccurate to say that battery systems like the one supplied by Tesla can handle all the chores of a stable grid, but its presence within the grid structure prevented a cascading grid failure that could have left hundreds of thousands of customers without power.
Experts predict that as battery prices continue to fall, grid storage will become more common and serve more purposes. It is interesting to note that the electricity stored in the Horndale Power Reserve comes from wind turbines rather than solar panels, reminding us that when it comes to storage, batteries don’t really care what the source is of the electricity they store. Electrons are electrons and Tesla makes equal-opportunity electron storage solutions.