Huge solar tower and hydro storage project takes shape in South Australia

The first commercial scale project of a landmark Australia solar storage technology is getting ready for its formal opening later this month, and the technology now has a pipeline of more than a gigawatt of proposed projects, according to one of its backers.

RayGen, backed by the likes of utility AGL and global oil giants Chevron and Equinor, has been working on the 50MWh “solar hydro” storage facility in Carwarp, south of Midura in Victoria, for several years.

The technology combines solar towers (where light is reflected from mirrors into collectors on top of a tower) and “solar hydro” storage, where the energy is stored in water.

The 4MW solar tower component at Carwarp (pictured above) was connected to the grid a year ago, but supply chain issues caused by Covid led to delays to the 3MW, 17-hour (50MWh) of long duration storage component.

The European renewables developer Photon Energy has revealed in its latest results announcement that the Carwarp facility is to be officially opened later this month, and that it now has a project pipeline of around 1.2GW of projects, mostly on utility scale projects using RayGen technology.

The market for long duration storage is opening rapidly, given the high renewable energy targets (82 per cent by 2030), the closure of coal fired power stations, and the difficulty and cost over-runs for pumped hydro projects.

Photon says it has also advanced the development works of the Yadnarie project on the Eyre Peninsula in South Australia, which will use the RayGen technology, although it has had to trim the size of the projects to 115MW (ac) after  geotechnical investigations and environmental reviews.

“We have had to revisit the areas of land that are suitable to construct on, and have therefore downsized the project,” the company said in its report to shareholders. Still, it will have storage capacity of 3.6GWgh, according to the project website.

Last year Photon said the Yadnarie project could be sized at 300MW and cover more than 1200 hectares. It has now been scaled back to around 900 hectares, and 200MWp (DV), or 115MW (ac).

RayGen would not comment directly on the Yadnarie project, which is one of several projects totalling “many gigawatt hours” in advanced stages of planning. AGL is also looking at the technology on the site of its now shuttered Liddell coal generator in NSW.

“RayGen and Photon Energy are collaborating on exciting growth opportunities for RayGen’s technology,” CEO Richard Payne said in a statement.

“These projects will showcase our ability to provide low cost, long duration energy storage, support system strength and increase renewable share of grid electricity.”