“Like riding a bike:” First big battery in Australia’s biggest coal grid enters full production

The first big battery in New South Wales has officially reached full production, but it will be soon be joined by at least another seven big batteries in the state in coming years, and likely more as the government rolls out its own infrastructure plans.

The 50MW/75MWh Wallgrove Grid Battery (WGB) in Western Sydney was the site of the federal government’s major funding round that will support advanced “grid forming inverters” in eight big batteries with a total capacity of 2GW/4GWh.

Wallgrove, owned by Transgrid and operated by Iberdrola, also received support from the Australian Renewable Energy Agency under its separate Advancing Renewables Program and the NSW Government’s Emerging Energy program.

The battery is the third Tesla grid-scale system in the world to demonstrate synthetic inertia – operating in “virtual synchronous machine” mode – and helped pave the way for the latest funding round.

Grid forming inverters are considered essential to reach 100 per cent renewables because they provide many of the grid services delivered by coal and gas.

“Our trial of network services like synthetic inertia paved the way for this next generation of batteries and will provide critical learnings while also delivering grid stability at a lower cost for consumers,” Transgrid CEO Redman said.

Redman says the power system currently relies on inertia provided by large spinning turbines inside coal, gas and hydro generators to maintain a consistent frequency and help the system ride out any disturbances.

NSW is the state with the company’s biggest coal grid – more than 10GW, and most are expected to retire within a decade.

As coal-fired generators retire and more wind and solar generation connect to the grid, alternate sources of inertia will be needed to stabilise the network. Batteries can help fill this gap by using software to mimic the mechanical movement of turbines much like technology replaced the cogs to produce the digital watch.

“Inertia is like riding a bike, when you take your feet off the pedals it keeps rolling, but not for long, which is why we need to maintain inertia in our energy system to keep it operating,” Redman said.

“Currently synchronous generators or condensers can deliver inertia for stability, but batteries can also provide a greater range of benefits at a lower overall cost. They can also store excess renewable energy and then release it when consumers need it to help keep energy prices down,” he said.

Transgrid says that – to date – WGB has exported over 23GWh of energy.

The other big batteries to be built in NSW are the massive Waratah Super Battery, whose primary role will be in acting as a sort of , and the 30MW/30MWh Sapphire battery, to be built next to the wind farm of the same name, which is also the biggest in Australia.

Another three big batteries are to be built by Edify Energy next to the Darlington sub station in the south-west of the state, also next to the biggest solar farm in NSW.

Another 250MW/500MWh battery will be built at Liddell, on the site of the coal generator about to be closed. It received funding under ARENA’s grid forming inverter program and will likely be expanded over time.

The 50MW/60MWh New England battery, another to receive support under the NSW program, is already under construction.

Other big batteries are likely to be built at Eraring, in and around the Mt Piper and already closed Wallerawang coal fired power stations, and next to other wind and solar farms in the state.

Se RenewEconomy’s Big Battery Storage Map of Australia