A new innovation from RayGen

RayGen’s Solar Power Plant transforms the Renewable Electricity Storage Market

RayGen’s Solar Power Plant is a ground-breaking dispatchable electricity solution that will provide large-scale renewable generation and cost-effective, long-duration electricity storage. The Solar Power Plant is an innovative combination of RayGen’s PV Ultra and Thermal Hydro storage technologies. Our solution offers dispatchable generation that can follow a baseload day-night demand curve and support the grid via synchronous generation and the ability to respond to grid variability in seconds. The Solar Power Plant transforms the economics of solar storage by using PV Ultra’s unique by-product heat to boost the efficiency of thermal storage.

Thermal Hydro: large-scale energy storage

Thermal Hydro is an innovative alternative to Pumped Hydro, with fewer siting limitations. Thermal Hydro stores electricity energy as a temperature difference between two water reservoirs: one hot, the other cold.

The hot reservoir is heated to 92⁰C with the excess heat captured from the PV Ultra system. The cold reservoir is cooled to 2⁰C using an electrical chiller, supplied with electricity either from PV Ultra or the grid. The stored temperature difference is used to generate dispatchable electricity using an Organic Rankine Cycle engine – widely used in industry for waste-heat-to-electricity generation.

Diagram: Thermal Hydro compared to Pumped Hydro

Thermal Hydro’s 90⁰C temperature difference stores equivalent electrical energy to a Pumped Hydro system with a head of 1,000m. (Conversely, for a typical hydro plant with 250m head, Thermal Hydro requires only one-quarter of the storage volume for the same energy stored).

Revolutionising the economics of solar storage

Thermal storage has great potential to provide large scale, low impact energy storage using existing mature technologies. Several other organisations are testing various systems which convert electricity into stored heat, which is then used to generate dispatchable power.

However, conversion from electricity to heat and back to electricity has a low round trip efficiency (RTE <50%) which results in poor economics. By pairing Thermal Hydro with PV Ultra, RayGen has been able to boost the RTE towards 100%, representing a breakthrough in the levelised cost of electricity for thermal storage.

The result is a renewable energy storage solution that provides baseload power at low cost.

PV Ultra: Solar co-generation

PV Ultra is a world-leading solar co-generation technology, designed and manufactured by RayGen in Australia. PV Ultra is among the world’s highest efficiency solar products (setting a world record for solar system efficiency in 2014 with UNSW).

Diagram of RayGen’s PV Ultra