South Australia looks to more big batteries to maximise wind and solar exports

The South Australia government has flagged investment in big batteries to support the new $2.3 billion transmission link to NSW, and the existing links to Victoria, to ensure maximum exports of wind and solar to neighbouring states.

The proposal has been unveiled in a new “Renewables Export Plan” announced just days before the state election on Saturday, which looks to be hanging in the balance with a result too close to call.

“The Marshall government will look to turbo charge the SA-NSW and SA-Victoria interconnectors to deliver even lower power prices and attract hundreds of millions of dollars of renewable projects to South Australia,” deputy premier and energy minister Dan van Holst Pellekaan said in a statement.

“The Renewables Export Plan will identify the right mix of technologies such as batteries that can increase imports and exports over interstate power lines and deliver more renewable energy zones.”

Big batteries have already been used to maximise the transfer of energy along transmission links, because they can act as a sort of cushion that allows the links to operate at full capacity.

The Hornsdale battery in South Australia has achieved this to a certain extent on the existing link to Victoria, while the new Victorian Big Battery near Geelong has a specific contract to allow this on the main link to NSW during the summer months.

South Australia is currently dependent on its existing links to Victoria and when those links are maxed out at the capacity allowed by the market operator, wind and solar farms suffer considerable constraints.

The new $2.3 billion Project Energy Connect – which has begun construction on the South Australia end, with early works also starting in NSW – is expected to unlock new wind and solar capacity and fast-track the state’s target of reaching “net 100 per cent renewables”.

A big battery, or series of batteries, will in principal allow that link to operate at its full 800MW capacity. It is understood South Australia is looking options for batteries on each interconnector, or one located between the two.

“By backing up transmission lines with big batteries, we can turbo charge them to pull in and push out more power as we need it,” van Holst Pellekaan said, noting that other technologies to be considered could include “sag detection” which allow larger transfers in colder weather.

“That means more wind and solar farms can be built in South Australia, because they can export their surplus power interstate,” he added.

“Because we’re fixing the grid, in the last 12 months we’ve securely delivered 66% of our power from renewable energy. We’re on track for more than 80% of local needs by 2025.

“We’re committed to net-100% renewables by 2030 and are aiming at 500% of current demand renewables by 2050.”

The government says Project EnergyConnect will unlock an average of 1 terawatt-hour of renewable energy a year that would otherwise be “curtailed” because of security limitations or being surplus to local needs. It says that is equivalent to 7.25% of SA grid demand – enough to power 200,000 homes.

“Last month, the first towers went up on Project EnergyConnect, the largest transmission project in Australia’s history, and nearby stage 1 of the $3 billion Goyder South project at Burra is under construction – each creating hundreds of jobs.”

In NSW, Transgrid has also begun early works for its part of the new link, which will stretch from Robertstown in South Australia to Wagga Wagga in NSW, with an extension cord to the Victorian grid too.

The SA government says it will provide $150,000 to ElectraNet, the state transmission company, to develop the export plan and to study the option for batteries or other technologies.

South Australia leads the world in the transition to a grid dominated by wind and solar, but the topic has barely figured to date in state election campaigning, which has focused more on health issues.

Still, the Liberal government is trying to make an issue about Labor’s reluctance to support the transmission link – Labor’s Tom Koutsantonis says he does support it but is skeptical about its export claims – and the different strategies on green hydrogen.

Labor has focused on spending nearly $600 million on a green hydrogen plant in South Australia to encourage others to follow, while the Liberals have pledged to support a range of different projects and partners that it says can unlock more than $20 billion in investment.

The Liberal government is also boasting about the reduction in average electricity bills (an estimated $421 a year) and improved reliability in the four years it took power, just over a year after the state-wide blackout that led to the first Tesla big battery installation at Hornsdale.

“We’re ending Labor’s blackouts, reversing their price hikes with a $421 decease since the election, and moving to renewables faster. We want to go further, and secure more investment and jobs,” van Holst Pellekaan said.