WA shatters peak winter electricity demand records, as wind and batteries power up

A series of energy market records set over the past five weeks in Western Australia demonstrates the rapidly changing shape of electricity demand on grids high in rooftop solar and low on reticulated gas supply.

The records, shared on LinkedIn by Jai Thomas, coordinator of energy with the Western Australia government, are a new highs in winter peak demand on WA’s main grid, the South West Interconnected System, or SWIS.

The highest high, according to Western Power, was recorded on Monday, July 28, hitting 3,977 megawatts (MW) at 6:25pm, besting the record set just days before when demand hit 3,758 MW on Thursday July 24 at 6:45pm.

This week, on Monday, demand landed somewhere between those two numbers at 3,862 MW at 6:30pm, according to Open Electricity.

As Thomas notes, the operational demand records set over the last five weeks on WA’s main grid have been “underpinned by population growth, electrification of heating and a bloody cold, wet winter!

“In any case, Monday [August 25] was noted as the coldest Perth day in 50 years, and second highest winter electricity demand on record,” he adds.

Source: Jai Thomas, LinkedIn

Over the years since the broadscale uptake of rooftop solar, peak electricity demand has shifted from in the middle of the day to the evening, when the sun goes down and households power up as people return home from their working days.

There have been seasonal changes, too. Traditionally, summer has been the time of peak electricity consumption in Australia, as air conditioners switch on to fight the heat.

More recently, winter has started to compete in the peak demand stakes as more and more households quit gas and switch to electric heating and as electric heaters are run through the cold winter nights.

“We’ve definitely felt the cold driving new winter demand records. Great to see wind and batteries playing a role in keeping the lights on,” said Western Power on Facebook last month, after sharing AEMO’s post on the new WA demand records.

As you can see in the chart above, there was 320 MW of wind (green) contributing to second-highest peal demand on Monday, and 430 MW of battery energy storage discharging.

Clearly the vast majority of supply at that time in WA was still coming from gas (orange shades) but the combination of the battery and wind beats the supply from black coal at that point, which was 613 MW.

“The combination of colder weather and increased evening demand has made wind and battery storage assets key contributors to meeting the peak demand,” says Nicola Falcon, AEMO’s interim executive general manager WA in a LinkedIn post in July.

“They have played a vital role in helping to ensure we keep the lights on during these record-breaking times.”

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