As temperatures soared into the 40s, power was cut to up to 200,000 people across Victoria on Friday afternoon.

The outages came as the national energy market operator said it was desperately trying to avoid a Victoria-wide blackout.

Energy experts told The New Daily brownouts — a form of controlled blackout — will become “the norm” and warned supply and demand issues will “probably worsen”.

“We’ve been saying this for a long time,”, Construction, Forestry, Mining and Energy Union Victoria district branch secretary Geoff Dyke told The New Daily.

“The system is going to be short of power and on hot days when it’s under the most stress, it will probably get worse.”

Premier Daniel Andrews warned residents they were struggling through the hottest day since Black Saturday in 2009.

Hottest day since Black Saturday. Total fire ban for the entire state. Emergency warnings are active. For up to date information, please follow @VicEmergency, visit https://t.co/wCf9P35m4f, listen to ABC Radio – and please stay safe.

— Dan Andrews (@DanielAndrewsMP) January 25, 2019

Tasmania was also under the pump, with up to eight different fire emergency warnings in place during Friday.

“It is on the cusp of us not being able to contain fires,” said the Tasmania Fire Service.

The Victorian crisis saw the Australian Energy Market Operator shed 250 megawatts of demand, leading to rolling blackouts across Melbourne’s suburbs and in Geelong.

The blackouts were widespread across Melbourne’s north and west, and affected traffic lights as well as households.

The network struggled to cope with the high temperatures, surging demand and reduced generation availability.

“AEMO notes there may be Victorian residents and businesses who remain without power due to unrelated faults on the network,” the operator said in a statement.

AEMO would not tell The New Daily which major energy users participated in the Reliability and Emergency Reserve Trader mechanism in Victoria that allows the operator to pay industry to power down and free up energy for the wider system.

Previous businesses that have opted to power down for a price have included Bluescope’s steel operations, manufacturers Australian Paper and Visy as well as Alcoa’s Portland aluminium smelter in Victoria.

From the heart of Victoria’s power generation heartland in the Latrobe Valley in the state’s east, Mr Dyke said brownouts were “clear proof” the system didn’t have enough supply and expressed concern for ageing generators in the Valley, with some up to 35 years old.

“The system is slowly running short and you’ve got to ask: These are the stop gap measures? Blacking out customers? I don’t see how that can be a long-term solution,” Mr Dyke said.

Due to power issues, around 70 sets of traffic lights are out through suburbs from Clyde North to Corio. Follow the same rules as if the intersection had a stop or give-way sign or a painted line. Follow the direction of @VictoriaPolice and traffic management crews. #victraffic pic.twitter.com/5H6EdC0n7e

— VicTraffic (@VicTraffic) January 25, 2019

Meanwhile, residents in Victoria’s east were urged to leave the town of Timbarra because of an out-of-control bushfire.

A WATCH & ACT is current for Butchers Ridge, W-Tree & Murrindal for a bushfire near Timbarra that is not yet under control. The bushfire is travelling in a south-easterly direction towards Gillingall. Don't wait, leaving now is the safest option https://t.co/tCKACKDrGU #vicfires pic.twitter.com/KmBFgaO05j

— cfa_updates (@CFA_Updates) January 25, 2019

South Australia’s emergency diesel generators were fired up for the first time as the two-day heatwave began on Thursday. They were intended to help Victoria cope with the weather, but were not enough.

Adelaide suffered through a record 46.6-degree day on Thursday. For 25,000 South Australians, there were also power cuts.

SA Energy Minister Dan van Holst Pellekaan said those blackouts were due to failures in some of SA Power Networks’ equipment and not due to forced load-shedding.

On Friday, demand for power in Victoria was higher than anticipated, at almost at a record 9600 megawatts.

After the furnace-like conditions, relief came in the afternoon. The temperature at Aireys Inlet, on Victoria’s southern coast had dropped 11 degrees just after lunch and the cool change hit Melbourne’s CBD at 2.30pm.

Latest #VicCoolChange update. Cool change has swept through #Geelong with the temperature dropping from 44°C to 31°C. Avalon has now reached 45.6°C with 42°C so far in the City. Change expected in #Melbourne City at 2.30pm. Check latest observations at https://t.co/nSMGXKpXjZ

— Bureau of Meteorology, Victoria (@BOM_Vic) January 25, 2019

Bureau of Meteorology senior forecaster Michael Efron said the change would then move through the outer suburbs, bringing a temperature drop of about 20 degrees within an hour.

But the change brings risk of rain, thunderstorms and dusty erratic winds. There is also a risk of dry lightning, which could spark more fires.

In Tasmania, residents in central and western areas were being urged to curb their Australia Day long weekend celebrations as 53 fires continued to burn.

The Tasmanian Fire Service has cautioned people not to camp in bushland areas in the extreme fire conditions.

About 66,000 hectares have already been burnt by the fires and 500 fire personnel are on the ground in strike force teams. They include 145 from interstate and New Zealand.

Fire activity at Lynch Hill rapidly increased and the blaze is burning through button grass – a native species – prompting emergency warnings and text alerts for Zeehan and Renison Bell areas on Friday, authorities said.

“People in those areas who wish to leave early are asked to travel south to Queenstown and/or north-east to Waratah and beyond,” the Tasmanian Fire Service said.

“The best thing people can do in these conditions is leave early because it is the safest possible thing to do.”

Communities in the highland lakes area were also reminded to stay on high alert. There were emergency warnings in place for Shannon, Waddamana, Penstock Lagoon and Hilltop, and an evacuation centre open at the Bothwell Town Hall.

Another evacuation centre is open at the Huonville PCYC for those affected by the fire in the Tahune area.

-with AAP