AEMO warns of blackout risk in NSW on Wednesday and Thursday due to heatwave and supply outages

To help avoid electricity shortages, authorities will consider cuts to power use such as letting temperatures rise in museums and government offices.

NSW households and businesses face an ongoing threat that the power will go out – as soon as Wednesday afternoon – as an intensifying heatwave stokes demand to the limits of a struggling energy system.

Blackouts were averted on Tuesday after transmission network owner Transgrid cancelled planned outages, and generators such as Snowy Hydro provided more megawatts.

But as the area of western Sydney officially forecast to reach 40°C expanded beyond Richmond to include Penrith, the Australian Energy Market Operator (AEMO) said the availability of power on Wednesday and Thursday was at “risk”.

Demand is tipped to increase by about five per cent on Wednesday – to the highest level since June.

Meanwhile supply is down due to scheduled maintenance at three of the state’s four coal-fired power stations, which remain the backbone of the market.

AEMO, run by Daniel Westerman, sees ongoing risks to supply in NSW.

While it is standard procedure to take coal power units offline for repairs before summer, early hot weather has caught out operators and authorities.

To make matters worse, at one of the plants, AGL’s Bayswater generator, there has also been an unplanned outage due to a tube leak. AGL has accelerated work on the broken unit, but it won’t be back online until late Friday or early Saturday.

In the past, outages had less impact on the overall system because there was more baseload supply. That was before major coal-fired power stations closed in 2012 (Munmorah), 2014 (Wallerawang) and in 2023 (Liddell). But no new stations have opened.

Instead there has been a wave of wind and solar projects. These renewable sources have only provided a combined 21 per cent of the state’s power needs over the past year. Under-pressure coal has delivered 72 per cent.

The state government will on Wednesday morning consider whether to instruct staff in public buildings including museums to reduce air-conditioning use, pull down blinds and switch off equipment that isn’t being used.

Two of four units at the Bayswater coal-fired power station are offline. Picture: AFP’s David Gray

AEMO said it hadn’t asked large industrial users to scale back consumption. Yet.

“Ongoing heatwave conditions combined with significant generation outages in NSW tomorrow and Thursday remain a risk” of a power shortage, AEMO said in a statement.

“AEMO is actively managing the situation and has issued updated Lack of Reserve notices, urging industry participants to respond to projected demand requirements in the coming days.

“Additional measures may be necessary if supply forecasts worsen due to unexpected generation or transmission outages, or if demand rises beyond current expectations,” the market operator said.

“AEMO has not currently asked residents or businesses in NSW to use less energy during these heatwave conditions.”