One of the world's oldest operating coal-fired power stations will be switched off next month, leaving a gap in the grid.
The NSW Hunter Valley's Liddell power station was switched on in 1971 but as the nation looks to greener energy alternatives, the time for Australia's oldest operating coal-fired plant to power down has come.
The plant will be shut down on April 28.
But with Australia's energy system operator, AEMO, warning NSW will bear the brunt of the cost of mass coal-fired power exits, what will Liddell's closure mean?
What is Liddell's story?
The "Grand Old Lady", as it is fondly referred to by some workers, holds an impressive life span of nearly 52 years.
It is the oldest coal-fired power station still running in Australia.
Globally, only 1 per cent of power stations operate for more than half a century.
With four 500-megawatt turbines, AGL said it will have produced 430,952 gigawatt hours of power in its lifetime.
That's enough to power NSW for 6.5 years, at the current consumption rates.
Today, Bayswater and Liddell still account for almost a third of the state's energy needs.
There was a time when Liddell was the most powerful generating station in the country but buying the site wasn't an investment AGL initially wanted to make.
The company was trying to purchase Bayswater power station, located across the highway from Liddell, but the NSW government would only sell the stations as a pair.
So AGL acquired Bayswater and Liddell in 2014 for $1.5 billion.
Why is it closing for good now?
The power station is old.
AGL first announced the closure in 2015, declaring its commitment to decarbonising its electricity generation portfolio.
"AGL believes that the installed capacity and energy output from Liddell is best replaced with lower emissions and more reliable generation, with a longer life span," the company said at the time.
In 2017, the general manager described the power station as being on a "sliding scale to oblivion".
That same year, former prime minister Malcolm Turnbull was accused of bullying the company into keeping Liddell open beyond the 2022 forecast.
It was eventually pushed back to 2023, although Liddell's first unit to close, its youngest, was in April 2022.
"A lot of these power stations now are well beyond their economic lives and they probably should have shut years ago," resources analyst David Lennox said.
"But because there was no spare capacity to replace them with, they had to remain operational.
"The cost to rebuild and refurbish them and the life that they would have in a changing energy environment means it's just not worth the billions of dollars."
Will power prices go up?
Don't rule it out.
Energy system operator, AEMO, is already warning of a supply shortfall with five power stations to close across the country before the end of this decade — that's about 13 per cent of the national supply.
"Urgent and ongoing investment in renewable energy, long-duration storage and transmission is needed to reliably meet demand from Australian homes and businesses," AEMO chief executive Daniel Westerman said.
The NSW government has also ordered some mining companies to provide coal to power stations in a bid to keep costs down; this is at a reduced rate enforced by the federal government.
Mr Lennox was optimistic there would be "little impact" from Liddell going offline and said the closure had been "well managed" and planned over several years.
"Certainly there will be somewhat of an impact in terms of Liddell going off the grid, but at this point in time one would have to suggest that the other power stations that are on the grid would be able to make it up," he said.
"One can expect some volatility in their energy bills over the course of the next few years as we see these stations roll out and we see new green sources coming in."
"We're seeing the advent of more green sourced energy, but the problem with that is, it hasn't got - at this point in time - the capacity to meet the stable consistent baseline electricity generation as coal fired power stations."
What's the future like?
The mining and energy industry is the biggest employer in the Hunter electorate.
About half the Liddell workers will simply move across the road to the Bayswater Power Station, also owned by AGL.
That power station is due to close between 2030 and 2033.
About one in 10 workers have opted to try something new and for roughly a third, retirement was already knocking.
"Looking after our people has been our number one focus over the last couple of years of planning," AGL's program director of thermal transition Brad Williams said.
AGL is offering reskilling and mental health support to all workers.
"We've had a no forced redundancy policy."
About 20 staff will stay on for the decommissioning phase — getting the site ready for next year's demolition.
Beyond that, energy production will return to the site.
Liddell will be part of a Hunter Energy Hub and has attracted keen interest from mining billionaire Andrew 'Twiggy' Forrest.
A large-scale battery has already been approved by the NSW government and there are plans for solar and hydrogen power generation too.
And with billionaire Mike Cannon-Brookes exerting more influence over the company board, the pressure is on to fast-track renewables.
