The potential of the re-purposing of the existing plant was highlighted during a media site visit on Tuesday to a plant that has become a focal point for the increasing toxic energy policy debate.

During the tour, high-level AGL management outlined the potential, and likelihood, of the site being repurposed from coal-fired power.

AGL chief economist Tim Nelson said "repowering'' was an option for the site, due to its access to transmission services, adding that this could include gas or biomass.

Kate Coates, AGL Macquarie general manager, also said the best option for Liddell was to consider how to repurpose the site.

The AGL board had previously said it would consider installing gas-fired turbines to replace coal at the plant and, in its recent power generation infrastructure rehabilitation document, the company did outline plans for potentially repowering Liddell.

It cited the example of using coal to gas as an example of how it might change the nature of power generation at the site.

Ms Coates said the cost of converting to gas would be high but could not say if it would be greater than the cost of rehabilitation.

She added that a number of similar projects had been carried out in Britain.

During the tour, AGL Macquarie head of operations Kevin Taylor outlined the importance of the site's existing transmission infrastructure as one reason that repurposing or repowering was a strong potential option.

Energy industry pundits are split on the likely future of Liddell beyond 2022. Most believe the company is unlikely to relent to the government's request to extend the operation beyond its closure, but many are forecasting a shift to repurposing the site.

"A gas installation at Liddell is a real alternative," an unnamed energy industry insider told Fairfax Media.

"These conversions have happened in a few places around the world. We've seen it happen before with the Tallawarra Power Station."

Tallawarra operated as a coal-fired plant from 1961 to 1989 in Shellharbour, in NSW. A new gas-fired plant was rebuilt on the site to ensure energy reliability to the region.

The move came as Opposition leader Bill Shorten slammed the government's position on Liddell and gas.

"The energy crisis we're facing right now is bigger than one power plant - it's a national problem that demands a national solution," Mr Shorten said.

He called on Turnbull to "pull the trigger" on gas export control, and to improve the Australian Energy Market Organisation's gas pricing information, as recommended under the Finkel Review.

Doing so will help ensure more Australian gas, above and beyond Santos' dedicated 30 petajoules, stays in Australia both to solve the growing energy crisis, and improve market conditions for Australian manufacturers looking to secure long-term energy contracts.

"What on earth are they waiting for?" Mr Shorten said.

"They have had the power in their hands for months now and has done nothing. We need Australian gas for Australian jobs - and the Turnbull government is letting it go overseas."

AGL operates the 50 megawatt Hunter Valley gas-fired power station and the Newcastle Gas Storage Facility (NGSF), about 120 kilometres south-east of Liddell. Tallawarra is capable of processing up to 66,5000 tonnes of LNG a year. AGL also operates the Torrens facility, the largest gas-fired power station in Australia.

The energy insider said, if Liddell became gas powered, it would mean AGL would retain control of the entire chain, which could also create a headache for regulators.

"They'll produce the gas, send it to themselves, then generate power for the end consumer," he said.

"Only week ago - after meeting with Andy Vesey - the Commonwealth Government announced it had directed the AER to 'make sure electricity generators are playing by the rules'.

"If there is a suspicion that AGL is currently gaming the system, then having it gain control of another part of the supply chain, such as the gas supply to a large, AGL-owned gas-fired plant at Liddell, would seem to invite more opportunities for price manipulation."

This was dismissed by the ACCC, which did not believe AGL closing its upstream and downstream supply for power generation and retail would be anti-competitive under the Competition and Consumer Act.

AGL has previously tried to expand its gas operations in the regions surrounding Liddell through its coal seam gas assets in Gloucester, as well as in Camden, south of Sydney. But the group announced a decision to halt all coal seam gas exploration and production in the face of sustained political and community opposition.

Gas has been targeted by the government as a potential resource to bridge the expected shortfall in energy supply.

The Turnbull government has already arranged deals with oil and gas companies such as Santos to divert up to 30 petajoules of LNG next year to ensure the reliability of supply.

During the visit, half of the station's four units were offline and the two remaining units were running at a reduced capacity.

One unit was offline for maintenance while the other was out of service due to an unknown failure.

An AGL spokesman said the two functioning units were only providing power to the nearby Tomago smelter, which usually accounted for a large percentage of energy generated at the site.

"The demand of Tomago on the system is essentially the sum of our output today," the spokesman told Fairfax Media.

It is understood the smelter alone accounts for more than 10 per cent of NSW's entire energy demand.