Redflow supplies battery “backbone” for Swansea University solar minigrid

An award-winning UK solar research project at Swansea University has chosen the zinc bromine flow battery technology of Australian company Redflow as its “energy storage backbone.”

Redflow said on Thursday that Swansea Uni had installed 120kWh of the Brisbane-based company’s ZBM3 batteries to store the energy generated by a building made up of integrated thin-film PV and a “solar wall” used to supply warm air to a heat-pump for space and water heating.

The solar classroom has so far proven the Active Buildings concept by generating more energy than it has used over an annual cycle, according to the University, and during summer months is expected to send excess power to grid, too.

Redflow said its battery technology had proven the right fit – quite literally – for the job, given the company’s 10kWh units were the only commercially available flow battery energy storage system that allowed accurate sizing for the 120kWh system.

Another advantage, Redflow said, was that the batteries operated “out of the box” with the Victron inverters and controllers that provided the power conversion for the Swansea University minigrid.

But the ability of the batteries to deliver 100 per cent of the rated system energy each day, without degradation in capacity over time, was the key attraction for the University team.

“These characteristics were crucial considerations for us,” said Tom Griffiths, a Technology Transfer Fellow at Swansea (Smart Systems).

“Our application requires battery discharge duration of 4-8 hours depending on the time of year, making Redflow’s flow battery the ideal fit for our requirements in comparison to more conventional lead-acid or lithium alternatives,” he said.

Redflow CEO and managing director Tim Harris said the use of its batteries as part of a renewable energy mini-grid was an area the company intended to explore further.

“This project with its dual renewable generation sources will be a bench-mark for flow-battery minigrids,” Harris said.

“This is an emerging segment that Redflow is focussed upon, having recently deployed some PV-only minigrids in the agricultural sector in Australia.”

Those projects include a Western Australia farm that has 40kWh of Redflow’s ZBM2 batteries alongside a rooftop solar array to gain some energy independence from the reliably unreliable local grid.