Sodium and flow batteries to be trialled for long duration solar shift in remote microgrids

Two long duration battery systems using innovative technologies will be tested on remote microgrids in Western Australia as part of a state and federal government-backed trial on managing high levels of solar in off-grid communities.

Horizon Power is to pilot a six-hour sodium sulphur battery in Carnarvon and a four-hour zinc bromine flow battery further north in Nullagine in the program, which is backed by $2.85 million in funds from each of the Australian Renewable Energy Agency (Arena) and the WA government.

The 250 kW/1,450 kWh BASF sodium sulphur battery – a type of molten-salt technology often referred to as a NAS battery – will be the first of its kind in Australia to connect to a regulated network, supplied and installed by Allset Energy.

The 100 kW/400 kWh zinc bromine batteries from Brisbane-based outfit Redflow will be trialled in Nullagine’s summer temperatures which reach well over 40°C.

Arena says the project, expected to be up and running in early 2025, will test each battery’s ability to shift rooftop solar power generated in the middle of the day to the evening, as well as demonstrate how they can work alongside lithium-ion batteries for optimal network service delivery.

WA utility Horizon Power has a number of lithium-ion batteries installed on networks it operates but is looking for longer duration energy storage solutions run its Distributed Energy Resource Management Systems (DERMS) more effectively. 

Arena says the ability of zinc bromine and sodium sulphur batteries to withstand higher ambient temperatures over long periods and store power reliably with less system degradation is particularly important in remote community microgrids and offers a “distinct advantage” over current li-ion technology. 

If the trial is successful, the hope is that these longer duration energy storage technologies will be used to accelerate the rollout of DERMS across Horizon Power’s 34 service areas and power more communities with locally generated solar power.

“Local utilities are developing strategies to determine how they can achieve their net zero targets given their enormous energy storage needs,” said Redflow CEO Tim Harris.
 
“Horizon Power’s groundbreaking program seeks to develop the expertise needed to integrate LDES technologies such as Redflow’s to ensure resilient and cost-effective power systems throughout Western Australia’s remote communities.”

Federal energy minister Chris Bowen says the trials are part of “sweeping efforts” to ensure no one is left behind in the transition to renewables.

“We are committed to investing in technologies like microgrids, to improve reliability and resilience of electricity supply for regional and remote communities – getting renewable energy to people where and when they need it.”

“We know that firmed renewables are the cheapest form of energy,” added assistant energy and climate minister Jenny McAllister.

“These trials, which focus on adapting to dynamic conditions and extreme heat, will help efficiently supply renewable energy to communities no matter where they live or how hot it gets as our climate changes.

“These technologies have the potential to be scaled to communities in Australia’s extreme climates, giving locals greater energy resilience, control, and independence.”

Horizon Power CEO Stephanie Unwin says the trials build on the utility’s years of experience in rolling out stand-alone solar and battery microgrids.

“Horizon Power was an early adopter in battery energy storage, and for the past 15 years we have been exploring how energy storage can best be used to promote increased uptake of renewable energy across regional WA,” Unwin said.

“Our latest trials will continue our exploration of Long Duration Energy Storage (LDES) technologies which are suitable for withstanding the extreme temperatures of our regions, providing valuable insights which will support with future deployment of the batteries in our regions.”