Keeping homes powered on scorchers relies on shutting one industry down

Saturday, 13 December 2025 07:28

What is saving most Australians from blackouts is an arrangement with some of the country's biggest users of electricity.

Some days are made for air conditioning.

On those days where the mercury rises to the angry end of the 30s, those of us with air-con wondered what we did without it.

But it's on those days Australians stand the greatest risk of losing it all to an unwelcome blackout.

While the grid used to be under the most pressure on winter nights, things have changed, according to the Grattan Institute's Alison Reeve.

"The winter evening peak in the old days was just everyone coming home and putting the heating on at the same time," she said.

"Now what it's shifting to is everyone putting the air conditioning on at the same time."

Adding more pressure on the grid is an ironic issue with coal generation.

If it gets too hot, coal plants start to struggle.

Aluminium smelters are asked to shut down temporarily rather than cause blackouts elsewhere.

"Coal generators are more likely to break down because they don't cope very well with high heat," Reeve said.

"So when that happens, that can also cause a blackout or a brownout, because you've got such high demand at the same time."

What is saving most Australians from blackouts is an arrangement with some of the country's biggest users of electricity.

When the grid is under too much strain, the major users are asked to switch off.

The biggest offenders are aluminium smelters.

Australia has four aluminium smelters that account for 10 per cent of the electricity used in the country.

Aluminium smelters are the biggest user of electricity in Australia.

The Tomago smelter on the NSW Central Coast uses as much power as a city of a million people.

And high power bills has meant the smelter is now turning to the federal government to keep them open.

But switching them off is an expensive endeavour.

The smelters run 24 hours a day, and any shutdown is problematic.

"It doesn't happen that often," Reeve said.

"It's there if we need it."

Aluminium smelters like this one in Portland use a massive amount of electricity.

And while rooftop solar panels are helpful for the grid on hot days, it is taking the edge off rather than carrying the load.

Solar panels generate the most electricity around 1pm, but the usual peak time for power usage is about 5pm. By then, the sun has started to set and less electricity is being generated.

So how can the average punter reduce the risk of blackouts on a hot summer's day?

The best options are to add a few degrees to the air conditioner, and, obliquely enough, make sure your aluminium cans are getting recycled.

DOWNLOAD THE 9NEWS APP: Stay across all the latest in breaking news, sport, politics and the weather via our news app and get notifications sent straight to your smartphone. Available on the Apple App Store and Google Play.