Plans by billionaire steel plant operator Sanjeev Gupta to build up to 1,000MW of large-scale solar and storage in South Australia appear to have no network limitations, with the Australian Energy Market Operator saying there is plenty of spare capacity in the local grid.

AEMO’s Integrated System Plan, released on Tuesday, looks at potential renewable energy zones around the country to try to understand what upgrades and extensions need to be made to accommodate the shift to a majority renewable energy power supply over the next decade.

One of the most interesting of these is South Australia, which already sources around 50 per cent of its demand from wind and solar, and has enough projects under construction or contracted to take this to 73 per cent by 2021.

But it could go much higher.

Gupta’s plans to build 1GW of solar to supply the Whyalla steelworks and other large industrial customers – and other big projects such as the DP Energy renewable park, Neoen’s Crystal Brook green hydrogen hub – and a number of pumped hydro storage proposals could take this figure to around 100 per cent.

The ISP report analyses nine potential renewable energy zones in South Australia and states a preference for two – northern South Australia, around the industrial cities of Whyalla, Port August and Port Pirie, and the mid-north, stretching inland north from near Adelaide and including some of the state’s major wind developments to date.

Both the Northern and mid-north region, AEMO notes, could take an additional 1,000MW of new renewable energy capacity without the need for network upgrades.

The Northern region, including Whyalla and Port Augusta, boasts high quality solar resources and includes locations where pumped hydro resources could be developed.

It also has strong network connection with the major load centres, consisting of multiple 275 kV transmission lines. “This means there is sufficient capacity in the REZ to connect around 1,000MW of new generation without needing major regional transmission network augmentations,” it says.

That means it is very resilient to large changes in network losses and marginal loss factors.

It notes the mid-north region has “moderate quality” solar and good wind resources, and also includes locations where pumped hydro resources could be developed.

It, too, has strong connection to the major load centres in South Australia than other candidate renewable energy zones. “There is sufficient transmission capacity to connect around 1,000 MW of additional generation without needing major transmission network augmentations.”

AEMO also suggests that the Roxby Downs region, where the Olympic Dam and other mining projects are located, should be a priority renewable energy zone for solar generation in the medium term.

It already has a connection to the shared network by a single-circuit 275 kV transmission line owned by BHP. Recently, OZ Minerals announced that it will establish a new transmission circuit through this region in a deal signed with SolarReserve, which is to build the big solar tower with storage plant near Port Augusta.

“AEMO recommends that future renewable energy development in Roxby Downs be taken into consideration when considering this transmission line development – for example, by using transmission towers that could accommodate a second circuit at a later date.”