Network approval paves way for solar and storage at some of Australia’s biggest mines

It said in March earlier this year that it is looking at renewable energy options for the expansion of its Prominent Hill mine, the development of the $1 billion Carrapateena project, and the possible development of West Musgrave, but also noted in its latest quarterly report that wholesale market falls could deliver a 20 per cent saving to its current bills.

Back to Alinta, as we reported last week, the 35MW/11.4MWh battery next to the Newman gas-fired generator has been an eye-opener, and proved it can operate in standalone mode, has grid-forming capability, and can provide frequency control by acting as a virtual generator.

It’s the ability to provide enough fault current to keep the grid stable whenever everything else goes pear-shaped that has proved the most valuable. The nature of such grids means that generators can be lost, and large loads can be lost.

“We have had situations where we had no thermal generators, and the battery’s been able to hold the transmission line by itself,” Alinta’s Gary Bryant told RenewEconomy

And the same thing has occurred when up to 80 per cent of load is suddenly lost. “The battery has responded within milliseconds,  absorbing the excess load until the system restabilises to ensure no loss for other customers,” Bryant says.

Previously, because of the slower response of the gas generators, cascading losses were often unavoidable. “We’ve definitely had fewer outages – our customer’s very happy with improvement of power quality,” he says.

Bryant said last week that as that network is pushed out further “it is inevitable” we will put in a second unit, but that also depends on how much renewables is put on the grid.

“We are looking at extending out network beyond Roy Hill, and using solar as much as we can. The more (solar) we put there, the more we need system security.”