A remarkable new statistic has emerged on the biggest isolated grid in Australia – and the world for that matter – with gas generation being reduced to a single megawatt of output at one stage last week as the share of renewables hit 83 per cent.
The new record low for gas output in Western Australia – which occurred at 12.40pm last Saturday – was noted by Open Electricity and reflects the radical reshaping of the nation’s grids with high levels of rooftop PV, and with a growing penetration of battery storage.
Five years ago the minimum output of gas generation in W.A.’s main grid – known as the South West Interconnected System – was more than 200 MW.
A decade earlier it was more than 600 MW, but gas is now mostly relegated to a “peaking” role thanks to the growth of wind and solar, and rooftop PV in particular, and the recent surge in big battery storage in the state, including the country’s biggest battery at Collie, a 560 MW, 2,240 MWh facility owned by Neoen.
The relegation of gas to a single megawatt reflects the influence and flexibility of battery storage. The state’s new big batteries were charging at the time, soaking up around 211 MW of rooftop solar.
But, if needed, they could quickly change direction and inject power into the grid should – say – passing clouds diminish the output of rooftop PV, a transmission line trip, or a problem emerge in the state’s remaining and ageing coal generators.
Gas generation will continue to contribute a significant share of renewables in the W.A grid, particularly after the remaining coal generators shut down at the end of the decade. Gas currently accounts for one third of supply.
But with another gigawatt or more of battery storage capacity (and more than 4 GWh of storage) to be delivered in the next, the dynamics will change.
