Remember the energy company executive who stood there awkwardly while South Australian Premier Jay Weatherill delivered a stinging assessment of federal Energy Minister Josh Frydenberg at a particularly memorable press conference?

Andy Vesey witnessed Premier Jay Weatherill's stoush with Josh Frydenberg first-hand. ( ABC News )

If you thought that was cringe-worthy, things just got even more uncomfortable.

That man — Andy Vesey — runs South Australia's biggest electricity producer and retailer AGL.

And now the Premier is condemning the company over claims it has shelved plans for new investment, because of the State Government's intentions to intervene in the energy market.

"We've been screwed for too long by large power companies, it's as simple as that," Mr Weatherill said while defending his $550-million energy plan at a press conference in Port Pirie.

"When they [the then Liberal government] privatised ETSA [Electricity Trust of South Australia] they left the power in too few hands.

"We're taking the power back for the people of South Australia.

"A few people are upset about that because they're not going to be able to make their enormous profits out of South Australians. And if they're squealing about that, we're happy."

AGL shelves investment plan

The Premier was responding to a report in the Australian Financial Review, which claimed AGL had put on ice its own plans for new generation, because the Government's plan includes a taxpayer-funded gas generator.

According to the Financial Review, Mr Vesey last week told investors the state-owned, 250-megawatt plant was the "most problematic" element of the energy plan, adding it was "wishful thinking" to expect the plant would not compete in the electricity market.

South Australian Energy Minister Tom Koutsantonis said the turbine in the Government's gas generator would operate regularly to provide stability services to the grid, but insisted the unit would only be switched on to produce electricity if the Australian Energy Market Operator orders load shedding.

"We're not going to have South Australians load shed again," Mr Koutsantonis said.

"We want to make sure that we have backup generation in place.

"Our generation will not be competing with AGL."

Mr Vesey has since issued a statement clarifying his comments on the Government's energy plan.

"As we said to our investors last week, it's true that our proposed investment blueprint now needs to change, given recent South Australian policy announcements," he said.

"However, I can also confirm that AGL is developing a new investment proposal to meet the needs of consumers in South Australia.

"While it will contain different components, it will be as extensive as our previous blueprint."

AGL 'making super profits' by freezing investment

Mr Koutsantonis went on accuse the state's biggest power retailer of charging monopoly rent.

"AGL, with its ownership of one of the largest power stations through the privatisation of ETSA, have been charging extraordinary prices to South Australians," he said.

South Australia Treasurer Tom Koutsantonis says AGL has charging South Australians "extraordinary prices". ( ABC News: Lauren Waldhuter )

"What you're seeing now through our energy plan is their competitors and new investors coming into the market and if that means that AGL won't be getting the same super profits they've been getting over the last four years, well that's a good thing for South Australians."

The state Opposition Leader Steven Marshall seized on the reports of AGL shelving its investment, claiming it demonstrated the Government's plan was a failure.

"Less than three weeks after Tom Koutsantonis and Jay Weatherill put out their energy plan the wheels have completely and utterly fallen off," Mr Marshall said.

"Now we have more proof that this is a dog of a deal."

But Mr Koutsantonis said the price of electricity in South Australia would have justified AGL making new investments in the past five years, but the company had decided against because of its market power.

"The reason they haven't made that is they've been making super profits out of Torrens Island," he said.

The Energy Minister went on to suggest it would be a good thing if AGL put off its investment plans.

"Absolutely. Do we really want to see consolidation of more investment from AGL?" he said.

"Do we want to see the monopoly rent being charged more by the largest monopoly holders of our assets, or do we want more diversity, more competition?

"We don't want more consolidation of AGL's market power, we want less."

The Government has shortlisted three bidders to provide new power generation to fulfil 75 per cent of the South Australian Government's own energy needs.

The tender process was specifically designed to encouraged more competitors to the South Australian electricity market.

Awkward much?

Mr Weatherill was asked whether the latest stoush was prompted by the press conference in which he dressed-down the federal Energy Minister.

The Premier was a guest at the media event, which was held to launch AGL's virtual power plant in Adelaide.

Mr Weatherill brushed off suggestions his verbal stoush with Mr Frydenberg had put Mr Vesey and AGL offside.

"He thought it was a great laugh ... I had a chat to him the other day when he was in Parliament," he said.