Eraring and Vales Point power stations could be running multi-million dollar annual losses by 2025, the Institute for Energy Economics and Financial Analysis report found.

The report's authors - Tristan Edis and Johanna Bowyer - said "a huge amount of renewable energy supply is expected to be added to the National Electricity Market [NEM]" by 2025.

Sarah McNamara, chief executive of the Australian Energy Council - which represents coal, gas, hydro and renewable generators - said: "We are seeing major changes to the wholesale energy market as more renewables come into the system".

"That is putting added pressure on coal-fired generators in particular," Ms McNamara said.

"The key issues will be ensuring an orderly exit of older thermal plants, as well as investment in dispatchable generation and encouraging the right overall mix of resources and system services to maintain system security and reliability."

Origin Energy - which owns Eraring - said it would "continue to focus on running Eraring profitably as we plan for coal to be replaced with renewable supply, firmed by a mix of batteries, gas peaking plants and pumped hydro storage".

"While the challenges facing baseload plants have been well documented, we do not agree with [the new report's] simplistic analysis, particularly as it relates to Eraring Power Station," an Origin spokesperson said. "As one of the country's most flexible coal-fired generators, Eraring is one of the best positioned to respond to a lower wholesale price environment and has already been reducing output when it is not needed."

Origin said last week at the release of its half-year results that it was reducing spending at Eraring.

"We are changing the role of Eraring to better position it for increasing renewables."

Origin said last month that plans for Australia's largest battery at Eraring would support its "orderly transition away from coal-fired generation by 2032".

Delta Electricity has stated that Vales Point's "nominal closure" is due in 2029.

A spokesman for Delta Electricity said on Wednesday that it was aware of the institute's new analysis.

"It represents their interpretation of some economic modelling around the power industry," he said.

Mr Edis, the report's co-author, said the market was "facing a tidal wave of new [wind and solar] supply, much greater than anything government authorities or market analysts forecast or even contemplated just two years ago".

"The supply added from 2018 to 2025 equates to over a third of the entire demand in the NEM, and more than eight times the annual generation of the Liddell coal-fired power station in NSW."

Ms Bowyer, a report co-author, said this extra supply would lead to "a collapse in output from many of the existing fossil fuel generators".

"We predict that gas power station output will fall by 78 per cent and coal output by 28 per cent by 2025, compared to 2018 levels."

She said the extra supply from renewables would be "several times greater than that lost from the closure of Hazelwood, Northern and Liddell power stations".

The report found Bayswater Power Station in the Hunter would still be in business by 2025, but much less profitable than in 2018.

Hunter MP Joel Fitzgibbon said the rapid growth of renewable energy projects might force coal-fired plants to "close earlier than the end of their physical lives".

"This is the strange thing about the constant calls for a more aggressive approach to climate change policy. All of our coal-fired generators will eventually come to the end of their physical or economic lives," Mr Fitzgibbon said.

"The last thing we need is government policy which artificially shortens their operating lives. That will only lead to blackouts and higher electricity prices. We need all the time the market is allowing to get more gas-generated firming power into the grid."

Nature Conservation Council chief executive Chris Gambian urged the NSW and federal governments to "set aside a substantial fund with billions of dollars to ensure no worker is left high and dry and to create jobs in coal regions".

"The Hunter Region can't reach its post-coal potential alone - it needs substantial support from the state and federal governments. That support is conspicuously lacking," Mr Gambian said.

"Change in our energy systems is gathering pace so coal communities need government help to get on board or they will be left behind.

"Germany created a 40-billion euro fund to help its coal communities develop new economic opportunities."

Poland, too, is set to spend billions to transition away from fossil fuels.

"We need something similar to ensure our communities don't suffer because of the rapid international shift away from coal," Mr Gambian said.

Australia's energy security chair Dr Kerry Schott said last week that renewables were penetrating the market faster than expected and putting coal-power generation under pressure.

Mr Edis said efforts to keep "inflexible coal plants afloat, let alone build new coal power plants" were likely to be counter-productive.

"Rather than propping up these plants which are getting very old, we need new government policies that support private-sector investment in dispatchable power plants that will be viable over the long term," Mr Edis said.

"To be viable they need to be highly flexible to work around changes in wind and solar output. And they need to be low emission if we are to deliver on our climate change obligations."

The report authors said the NSW government's Infrastructure Roadmap was an "essential response to this issue".

"It provides a well-structured and competitive process for underwriting new capacity that can replace coal power plants in advance of their closure. Importantly this will be run by an authority independent of political interference."

Ms Bowyer said having the right policies in place would allow the market to operate and renewable energy supply to take a dominant position.

This, she said, would enable the NEM's average wholesale power prices to continue to fall - "a significant thumbs up for electricity consumers everywhere".

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