Tesla’s 100-MW lithium-ion battery, known as the Hornsdale Power Reserve, is playing a valuable role for South Australia’s electricity supply during very high demand days.
The latest National Energy Emissions Audit from the Australia Institute shows that in early February, the battery was consistently charging up at night when prices were low, and discharging in the late afternoon, when prices were very high. Currently it’s still summer in the region so those were particularly hot days. The battery is connected to Neoen’s wind farm, around 140 miles north of Adelaide.
Australia Institute report author and energy expert Hugh Saddler noted that energy flows are capped at 30 MW because only 30 MW of the total battery capacity of 100 MW is committed to energy arbitrage and the remainder gets held in reserve to provide frequency control services.
Although 30 MW is hardly more than 1% of the peak demand on one of the days called out in the report, he told the Guardian that the first-of-its-kind battery is providing a useful service and demonstrating the valuable role energy storage can play in the system.
“While the watts may seem small in the context of the whole system, the SA battery is providing critical power at the critical moment — in effect taking the straw off the camel’s back,” Saddler told the Guardian. “The world’s biggest battery in South Australia is working in smooth synergy with wind farms.”
Besides providing critical power, the Hornsdale Power Reserve contributed to lower emissions. “In the year to January 2018, emissions from electricity generators supplying the [National Electricity Market] fell to 152.8 Mt CO2-e, as calculated by the [National Energy Emissions Audit] model, the lowest level since 2004 — a success of the Large Renewable Energy Target policy,” the Australia Institute report says.
Elon Musk announced last November that the big battery project had been completed, making good on a bet that he estimates would have cost him $50 million had he failed.
Australia has been grappling with rolling blackouts and high energy prices. In the audit, Saddler says that planning is under way for a number of battery projects in South Australia, Victoria, and other parts of the country.
“The experience of operating Hornsdale Power Reserve already demonstrates that multiple smaller energy storage facilities, which will certainly include both batteries and small pumped hydro projects, located close to wind and solar generators, are almost certainly better suited to matching variable supply with varying demand than a single monster project located a thousand kilometers or more away, via multiple transmission lines which often reach saturation capacity when demand for electricity reaches peaks,” he wrote.