RayGen connects solar towers to the grid, but storage component will have to wait

A Melbourne-based solar storage technology company hoping to combine solar power and long duration energy storage (LDES) has announced that one component of its flagship site in Western Victoria is now connected to the grid.

RayGen – backed by AGL and a host of big international energy companies – said on Wednesday that it is sending power to the grid from its Carwarp site just over 30 kilometres south of Mildura, using technology that uses mirrors to reflect sunlight to a high performance PV receiver mounted on a central tower.

The solar towers at this demonstration project have a capacity of 4MW, but RayGen’s plans to roll out its “solar hydro” long duration energy storage solution have been delayed by supply chain disruptions, and the shortage of semiconductors.

The commissioning of the water based storage component – rated at 3MW with 17 hours storage, or 50MWh – has been put back until early 2023.

“RayGen is excited to be delivering renewable energy to the West Murray Grid from our flagship site in Carwarp today,” said RayGen CEO, Richard Payne.

“Global supply disruptions have been a challenge not just for RayGen, or even the entire energy industry, but any company dealing with global logistics.”

The company has the support of major players alongside AGL, the Australian Renewable Energy Agency, as well as international energy giants including Norway’s Equinor, Schlumberger, Photon Energy and US fossil fuel giant Chevron, amid a global push to consolidate renewable storage and supply.

Long duration energy storage refers to a range of technologies which can store energy for more than 10 hours at a time, and consolidate the intermittent supply of renewables to the grid through the use of pumped hydro, flow batteries, solar thermal, and other avenues.

While there is much optimism surrounding long duration energy storage technologies and its potential role in replacing ageing fossil fuel plants, there remain a number of barriers to the industry’s commercialisation.

Significant funding is being funnelled into LDES globally, but the technology and investment required to maintain current and growing levels of global energy demand is immense.

RayGen’s proposal is to use water-based storage – hot and cold ponds – that allows energy to be stored for hours or days at a time, with what it says is the efficiency of traditional pumped hydro, but with fewer siting limitations.

A report from the Long Duration Energy Storage Council and McKinsey released in 2021 found that in order to reach net-zero power grids by 2040, investment would need to reach somewhere between $US1.5 to $US3 trillion ($A2.1-$A4.3 trillion).

In Australia, solar thermal stakeholders have flagged that a target or capacity incentive for renewable LDES would be required to support the nascent industry, which has not yet achieved the mainstream attention afforded to PV solar or wind.

Still, RayGen remains hopeful that a LDES industry is viable for Australia.

“We look forward to delivering Carwarp’s thermal-storage system by (the first quarter) of 2023 and showing Australia that the future of Long Duration Energy Storage is Australian made,” it said.