World’s biggest solar and storage project proposed for South Australia

What is being claimed as the world’s biggest solar and storage project – a 300MW facility with 3.6GWh of storage – has been proposed for South Australia by the Dutch-based solar developer Photon Energy, using Australian technology developed by RayGen.

Photon said in a media release on Wednesday that it had secured 1,200 hectares of land for what it said would be the biggest solar and storage project in the world, beating the current biggest at the Ouarzazate solar thermal facility in Morocco.

It did not identify where the land was secured.

“We are very excited to be developing this innovative and globally significant solar energy storage project in South Australia,” said Michael Gartner, the chief technology officer of Photon Energy and head of its Australian operations.

“The enviable solar resource and need for energy storage due to high penetration of renewables in this region is a perfect match for RayGen’s technology.”

Of course, the Photon project won’t be the biggest solar and storage projects in the world if the Sun Cable project in the Northern Territory goes ahead. That project envisages up to 20GW of solar PV and up to 42GWh of battery storage.

But RayGen’s technology is different, and integrates solar and hydro storage, and it is supported by some big name energy players including AGL Energy, which is backing a pilot facility at Cawarp in Victoria and potentially another at the site of its soon to be closed Liddell coal generator in NSW.

Other backers include the venture capital arms of oil giant Chevron, Schlumberger, and Equinor, who all participated in a recent funding round – along with Photon – that raised $55 million.

RayGen is currently building a 4MW/50MWh facility at Carwarp in Victoria, also backed by ARENA, that combines the main features of its technology – mirrors that reflect the sun on to solar towers and concentrated solar collectors, and water-based storage in large pits (see photo above).

The heat extracted from PV Ultra modules is stored as hot water in a thermally insulated reservoir, while electricity from PV Ultra, or the grid, is used to run a chiller to produce near freezing water in a second reservoir. And the stored hot and cold water are used to drive a conventional Organic Rankine Cycle engine.

“This project and partnership with Photon Energy Group support our vision to accelerate the transition to renewable energy,” RayGen CEO Richard Payne said in an emailed statement.

“RayGen’s naturally synchronous thermal turbine and long duration storage – at 24 hours – can support the South Australian grid and unlock a higher proportion of renewable energy. We look forward to sharing more information as this project develops.”

Photon, which says it is developing the South Australia project, says that the total solar generation capacity will be 300MW, although the grid connection capacity will be 150MW. (The excess will be deployed on site for storage).

The total target storage capacity is 3.6GWh, equivalent to 24 hours of storage. Photon says it is working on grid connections and hopes to complete the preparatory work by 2023.

RenewEconomy understands that it is one of a number of projects being proposed by the two parties. But there are a number of questions.

One is where exactly it is located, another is how it will be financed, given both are small companies and Photon to date has been involved in relatively small solar projects, and other projects such as the Lord Howe micro-grid.

RayGen has announced a series of project proposals in recent years, including in Victoria and China, but these have been set aside as the company refined its technology and added the hydro storage component.

RenewEconomy reached out to Photon for more details but did not hear back before publication.