It is being called a “world-first,” a fully dispatch-able renewable energy facility utilising what RayGen calls PV Ultra, a “solar hydro” concentrated solar and thermal storage technology. The Melbourne-based startup generates renewable energy and large scale energy storage by focusing sunlight with a field of aligned mirrors or heliostats onto a tower-mounted receiver containing an array of PV Ultra modules made of gallium arsenide PV cells. The heat extracted from the PV Ultra modules is then stored as hot water in a reservoir acting as a store. The ability to co-generate electricity and heat, the latter a captured by-product, makes the whole facility highly efficient.
In actuality, the hot water reservoir is complimented by a cold reservoir. The cold reservoir is chilled by electricity from PV Ultra and the grid. The temperature difference powers an Organic Rankine Cycle engine to generate electricity with a round trip efficiency of 70%.
“Australia’s energy transition will require storage solutions that can store power cost-effectively for hours, days or weeks and be deployed at large scale around the world,” said RayGen CEO Richard Payne. “RayGen’s flagship 4 MW/50 MWh plant is expected to offer storage at a fraction of the cost of recent battery projects. The project is in a renewable energy zone that has limited capacity to support pumped hydro,” continued Payne, “we will also be supplying synchronous power to the grid where it is critically needed in the West Murray region.”
RayGen, and its partners AGL and GHD, will utilise ARENA’s funding as part of the $6 million first phase to get the project to financial close and shovel ready. The first phase includes technical and commercial feasibility studies, commercial assessment, a connection agreement, off-take agreements, capital raising and a planning permit for a preferred site.
“With RayGen’s project we’re seeing homegrown innovation in solar PV now being used to find new solutions for dispatch-able renewable energy,” said ARENA CEO Darren Miller. “RayGen’s solution could complement other more traditional forms of storage such as grid-scale batteries and pumped hydro.”
At this stage, the grid-scale power plant is proposed to be built in Carwarp near Mildura, and be able to produce 4 MW of solar generation and 17 hours of storage. Of course, the great potential of this technology is in its scalability, the larger the reservoirs, the more storage. But, perhaps the great advantage of RayGen’s technology is not that it can be scaled up, but that it can be scaled down.
RayGen’s approach to storage is similar to a pumped hydro facility but it can be run out on a much smaller scale and much cheaper to boot. Moreover, thanks to the technology’s high efficiency, PV Ultra can generate the same amount of electricity as a normal facility with only a quarter of the land.
“With ARENA’s funding, RayGen is aiming to progress this project to be shovel ready by the end of this year and to prove its novel technology can be cost-competitive with batteries and pumped hydro,” continued Miller.
To say that there is excitement about the applicability of this technology is an understatement. ARENA has already funded RayGen with a total of $8.67 million to develop its PV Ultra tech and build the 1 MW PV Ultra pilot project in Newbridge, Victoria. The successful pilot project has been powering a local mushroom farm for two years.
Federal Minister for Energy and Emissions Reductions Angus Taylor said the project was a terrific example of how innovative technology development could potentially provide secure, dispatch-able power to help support grid stability in western Victoria and reduce emissions. “This project has the potential to save 10,000 tonnes of CO2 emissions per year and provide reliable and affordable electricity to more than 1,000 homes,” said Taylor.
Taylor is convinced “technology, not taxes, will be the way we deliver practical action on emissions reduction.” This is known as the Promethean position and is, of course, quite reasonable. But it is called the Promethean position because Prometheus stole the fire of creativity from the gods and gave it to mankind; that sounds an awful lot like a range of solar and renewable technologies we already have, and which Taylor isn’t supporting. So perhaps Taylor is less of a Promethean and more of a Procrustean, he may say he wants to utilise technology, but in actual fact he only wants the technologies that fit into the Procrustean bed he and his party feel comfortable in.
Financial close and construction commencement of RayGen’s project is expected this year with a date in 2021 penciled in for commission.