New South Wales, the state that relies on coal generation more than any other grid in the world, has also been Australia’s biggest net importer of electricity, a new report has found.

In the latest National Energy Emissions Audit, published last week by The Australia Institute, energy analyst Hugh Saddler said NSW had been relying on its neighbours on the NEM for up to a fifth of its demand in 2017.

This was despite the state having a minimal share of so-called “intermittent” renewable energy generation – just 9 per cent, including big hydro – and 91 per cent of its total generation mix coming from “baseload” fossil fuels.

“Consumption has been consistently higher than generation, by as much as 20 per cent, as net imports …(mostly) from Queensland and Victoria contributed significantly to total supply,” Saddler wrote in the report.

In South Australia, meanwhile – “the NEM region with by far the highest share of variable renewable generation,” at 45 per cent (and headed to 75 per cent) – electricity imports have been on the decline, he said.

“Net imports through the two interconnectors with Victoria were previously an important contributor to total state consumption.

“But interconnector flows are now moving steadily towards approximate balance,” Saddler added; “during every month from July to December, exports to Victoria exceeded imports from Victoria.”

The interesting contrast between the two states comes as a number of state and federal politicians, alongside Conservative media outlets, continue to argue that more coal-fired power generation is what Australia needs to improve cost and reliability of supply.

This argument continues despite the increasingly unreliable track record of the nation’s ageing coal plants, some of which – like the Liddell power station in NSW – predate colour TV in Australia.

And it continues despite the assurances from coal plant owners, including AGL Energy and Energy Australia, that coal is not an economically or enironmentally viable solution for future energy generation.

South Australia, meanwhile, is leading the world in its demonstration of how new technologies – like the Tesla big battery – can integrate increasing amounts of renewables into an established electricity supply system, Saddler said.

Interconnectors, he added, would also be an important part of a distributed renewables grid.

“It is important not to ignore the important contribution which interconnector exchanges with Victoria, and also exchanges between Victoria and Tasmania are playing in making best use of the mix of generation technologies across the three states,” he said.

“That explains why there is renewed interest in building a new interconnector between South Australia and either Victoria or New South Wales or, possibly, even Queensland.”