UK billionaire Sanjeev Gupta says the Whyalla steel works will not be the only asset that will be powered 100 per cent by renewable energy: he intends the bigger steel plants in Melbourne and Sydney to follow suit within years.

Gupta on Monday announced plans to build 1GW of solar and storage in and around Whyalla to turn the steelworks in the city “green with energy”. The mix includes large scale solar, pumped hydro, battery storage, and demand management.

But Gupta says his plans will not end there, and his Liberty OneSteel group is looking to renewables to power the company’s Sydney and Melbourne-based electric arc furnaces, which are much heavier users of energy.

“The Whyalla steel works do not have an enormous energy requirement. Our plants in Sydney and Melbourne are very, very heavy users and we’re hoping that all of it will be supplied by renewables,” Gupta told ABC Radio National in an interview.

He said that transition was likely to take a “few years”, and the company may initially use coal to “firm” the use of of wind or solar. But the intention was to move quickly to a full renewable energy supply, particularly as firming costs continue to fall.

The company says its investment in solar and storage and its shift to becoming largely its own supplier could slash its energy bill by around 40 per cent. That’s mostly because his current bill is ridiculously high. “To beat these prices is not difficult,” Gupta told the ABC.

Gupta’s now majority owned Zen Energy is expecting the 1,000MW of solar, battery storage and pumped hydro to be built around Whyalla will service other major energy users in South Australia.

He said it could, contrary to the warnings of former prime minister Tony Abbott, make Whyalla a centre of cheap green energy.

Gupta’s comments go completely against the view of the Australian Coalition government, which has long argued that heavy industry cannot be powered by renewables. Gupta intends to show they can, and for a much cheaper cost that will continue to decline.

He also insists that even bigger energy users, such as aluminium smelters, can be powered by renewable energy. He declined to comment on speculation that he was looking to buy the aluminium smelting business of Rio Tinto.

“Large aluminium smelters can be powered by renewables …. and Whyalla can be become a clean energy park and a centre of industrial activity,” he said.

He said it was no longer true to say that coal provided the cheapest source of power to large energy consumers. “That was possibly true not long aago. We are fast moving to a situation where balanced renewables are able to compete with fossil fuels.”

The starting point, however, was the need to not just look at prices, but also have a plan to reduce emissions.

“Right now (the share of) solar is very small – single digits,” Gupta said. (Actually, in terms of large-scale solar it is a fraction of one per cent in Australia, although many new plants are being built). “This transition is a long transition …. now is not the time to quit.”