AGL taps RayGen to build dispatchable “solar hydro” plant at Liddell

Australian solar technology firm RayGen will partner with AGL Energy to deploy the company’s innovative concentrating solar and energy storage technologies that could become a leading example of zero-emissions dispatchable power.

The project will be an early example of renewable energy supplies being paired with long-term energy storage facilities, with a 4MW concentrating solar PV project being built alongside a 3MW/50MWh ‘solar hydro’ facility providing 17-hours of dispatchable storage.

The soon-be-closed Liddell coal generator is likely to be the site of one of the two projects planned, and comes as AGL also considers a big battery for the Liddell site, starting at 150MW and possibly growing to 500MW.

The technology developed by RayGen uses concentrating mirrors to generate electricity using high performance solar PV modules, with excess heat produced by the plant being captured and stored as a source of dispatchable energy.

The $30 million project will store heat produced by the concentrating solar facility in a pool of water, the equivalent of four Olympic swimming pools in size.

A second “cold” pool of water, kept at temperatures around zero degrees through the use of chillers, will allow the project to produce a temperature difference between the two pools of around 90 degrees.

By using an organic Rankine cycle turbine, the project will be able to exploit the temperature difference between the two pools of water to extract the stored energy for dispatchable electricity generation.

RayGen will develop the project in partnership with AGL Energy, with the first stage of the project to be located at Carwarp in Victoria and a second stage planned for Liddell site.

RayGen says the project will enable the company to establish a new manufacturing facility that will allow it to expand its business. Ultimately, RayGen believes that large-scale deployments of its combined solar-storage technologies could provide dispatchable electricity storage at a cost below $100 per MWh.

Raygen said that it had successfully raised $27 million from private investors, which included AGL, Photon Energy Group Schlumberger New Energy and Chevron Technology Ventures.

The funding will be used to deliver the Carwarp project, as well as establishing a new 100MW production line for the company’s high performance solar PV modules, a significant expansion upon the company’s existing 25MW per year production capacity.

“We are thrilled to be partnering with such respected global companies as we deploy our technology and grow our business” CEO of RayGen, Richard Payne, said. “We are thankful for the outstanding commitment and support from all of our existing and new shareholders who share our vision to accelerate the global transition to decarbonised energy with our innovative technology.”

On top of the $27 million in private sector investments, Raygen has secured an additional $15 million grant from the Australian Renewable Energy Agency.

AGL has made a $5 million contribution to the project, helping to fund the construction of the solar and storage plant, and has agreed to serve as the sole off-taker for the project’s production.

AGL plans to close the Liddell coal fired power station in 2023 and has already commenced a pre-feasibility study into using RayGen’s ‘solar-hydro’ technology to provide replacement electricity supplies.

“RayGen’s technology has the potential to provide the same capabilities as other long duration storage technologies at lower cost and with fewer geographical constraints,” AGL’s Interim CEO, Graeme Hunt, said.

“The system is powered by a field of smart, rotational mirrors whose concentrated solar energy is combined with the energy stored across two water reservoirs to create a ‘hot and cold’ solar hydro solution.

“We believe the technology can be just as successful in the Hunter region and a key feature of our plans to transition the Liddell site into an Energy Hub, alongside grid-scale batteries and a waste to energy facility.”

The project secured additional funding support from ARENA, with the agency having provided early funding to RayGen to assist in the development of its concentrating solar technologies. ARENA CEO Darren Miller said the technology was like combining pumped hydro and a traditional solar farm.

“RayGen’s technology has many benefits for the energy market as we continue the energy system transformation being driven by renewables,” Miller said. “RayGen’s technology can provide longer duration firming for renewable energy generation. We are particularly interested in the potential for RayGen’s technology to deliver firmed renewable energy at a very competitive cost.”

RayGen is currently based out of Victoria, with facilities in Melbourne and Bendigo, and employs 35 staff.