Despite WA’s new big batteries, investment in storage alone is insufficient and WA needs more energy generation as the end of coal approaches and hot summer days increasingly turn into hot summer nights, says the latest review of our state’s electricity supply.
The Australian Energy Market Operator notes impending power shortfalls in the latest of its 10-year outlooks, which advise on what is needed to maintain reliability in WA’s South West Interconnected System grid, which serves most of the state.
The grid is one of the most isolated large power systems in the world, and thus particularly sensitive to changes in technology, generation mix, weather patterns and our consumption behaviours.
Recent years have seen record contributions from renewables, minimum demands, swings in load, and other new challenges.
Extreme heatwaves of the past two summers, one of which was the state’s hottest ever, set “numerous” records for peak air-conditioning demand that exceeded forecasts, including a new all-time maximum demand record of 4486 megawatts, set at 6.30pm on January 20.
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It says recent investments in over 500 megawatts of grid-scale battery storage has helped, but with peaks continuing to grow (and extend into summer nights), additional supply available late into the evening would be needed, particularly on hot nights with no wind, or with generator outages.
It’s all rather urgent due to the impending retirement of WA’s coal power stations, and the ability of new power sources to connect to the grid will depend on transmission upgrades, too.
It says additional longer (six-hour-plus) battery storage will help, but alone won’t meet these peaks without additional solar farms, wind farms or gas generators to top them up; next summer, the grid will need at least 50 megawatts more “dispatchable capacity”, available over a longer duration.
The summer after (2027-28), following the closure of Collie Power Station, at least 110 megawatts of new solar, wind or gas sources will be needed to avert more and more energy shortfalls.
The operator particularly identifies shortfalls in the eastern Goldfields and north country.
It notes the changing energy mix coming, with generation from wind, large-scale solar and rooftop solar now accounting for more than 40 per cent of total energy production.
Synergy’s Muja C Unit 6 Power Station was retired in April; Collie, the largest power station in the grid, will close in 2027; Muja D in 2029; and the ageing Pinjar gas turbines will close between 2029 and 2032.
The operator also notes the risk Bluewaters Power Station will not establish a new coal supply arrangement and may not be available past 2028.
But over 1.1 gigawatts of supply will be online before October 2027, including the Merredin big battery and gas-fired generation.
It also notes growth in rooftop solar and the government-subsidised home batteries expected to be installed in up to 100,000 homes over the coming years.