The Energy Storage Report 2024

Now available to download, covering deployments, technology, policy and finance in the energy storage market

‘Thermal hydro’ long-duration energy storage player Raygen gets SLB investment in Series D


RayGen, a startup developing long-duration energy storage (LDES) technology designed for pairing with renewable energy installations, has raised investment to kick off a Series D funding round.

The company has a novel technology it describes as ‘thermal hydro,’ based on using the temperature difference between two pools of water to drive an engine, paired with ‘PV Ultra,’ which is a sort of combination of solar PV with concentrating solar power (CSP).

This article requires Premium SubscriptionBasic (FREE) Subscription

Enjoy 12 months of exclusive analysis

  • Regular insight and analysis of the industry’s biggest developments
  • In-depth interviews with the industry’s leading figures
  • Annual digital subscription to the PV Tech Power journal
  • Discounts on Solar Media’s portfolio of events, in-person and virtual

Or continue reading this article for free

Headquartered in Australia with backing from European solar developer Photon Energy, RayGen has already inaugurated a plant in the Australian state of Victoria with 2.8MW/50MWh (17-hour duration) energy storage, with a ground-mount solar PV array and CSP heliostats, following on from a 1MW pilot project also in Victoria.

The company claims the round-trip efficiency of its solution is around 70%, while it manufactures its proprietary solar modules in the Australian state, and is currently commissioning a factory with 170MW annual production capacity.

In 2020, Photon Energy said it believed RayGen’s technology could enable: “the elimination of solar energy’s intermittency and ensuring its 24-hour availability at grid-competitive cost,” closing funding on the first project a year later through a Series C, and later securing a site in South Australia for a potential 300MW/3,600MWh project.

The Series D launch, which kicked off earlier this month (22 April), has been joined already by SLB (formerly Schlumberger), making a AU$30 million (US$20 million) follow-on investment in RayGen as well as signing a Strategic Development Agreement (SDA).

French oilfield services company SLB is making targeted investments into next-generation energy technologies, and according to a 2023 report from Bloomberg is pursuing only billion-dollar opportunities.

In 2021 SLB formed a partnership with US metal-hydrogen battery technology company Enervenue, investing in the California company’s “30,000-cycle” long-duration tech originally developed by NASA for use in space. SLB is investing in Enervenue and co-developing battery energy storage system (BESS) solutions together.

Last week, hosted a webinar sponsored by Enervenue, which went into detail on that technology’s claimed advantages over rivals, including lithium-ion.

Similarly, while capital raised in RayGen’s Series D from SLB and others will be used to expand the tech company’s manufacturing, supply chain and automation capabilities, the SDA will see SLB provide international sales and engineering support.

RayGen CEO Richard Payne told that SLB “will play an integral role in accelerating RayGen’s global impact.”

SLB is also a member of the international Long Duration Energy Storage Council (LDES Council), as a service provider to LDES technology developers including Enervenue.

State, federal governments invest in RayGen

Also announced the same day was AU$20 million investment in RayGen from the state of Victoria, through the government-owned investment group Breakthrough Victoria.

“We are investing in RayGen Resources because they focus on what Victoria needs – sustainability, scale and local manufacturing. Their innovative energy storage technology will help us better transition to renewable energy,” Breakthrough Victoria CEO Grant Dooley said.    

Other investors in RayGen include Equinor Ventures, Australian utility AGL, Chevron Technology Ventures and Photon Energy.

Last year, the Australian government, through the Australian Renewable Energy Agency (ARENA), also invested in RayGen through the previous Series C round, as well as supporting the company with AU$10 million grant funding towards a project. In total, ARENA has put around AU$40 million into RayGen to date, supporting six separate projects.

Basically, RayGen’s thermal hydro solution uses two bodies of water, like pumped hydro energy storage (PHES) does. Where it differs is that with PHES the two bodies of water are on different elevations and gravity is used to drive turbines and discharge energy to the grid.

With thermal hydro, one body of water is heated to almost boiling point, the other is cooled to close to freezing temperature. The temperature difference then runs an Organic Rankine Cycle engine. Run-off heat from the concentrating solar heliostats keeps the hot water hot, while solar PV or off-peak electricity from the grid keeps the colder water cool.’ publisher Solar Media will host the 1st Energy Storage Summit Australia, on 21-22 May 2024 in Sydney, NSW. Featuring a packed programme of panels, presentations and fireside chats from industry leaders focusing on accelerating the market for energy storage across the country. For more information, go to the website.

21 May 2024
Napa, USA
PV Tech has been running PV ModuleTech Conferences since 2017. PV ModuleTech USA, on 21-22 May 2024, will be our third PV ModulelTech conference dedicated to the U.S. utility scale solar sector. The event will gather the key stakeholders from solar developers, solar asset owners and investors, PV manufacturing, policy-making and and all interested downstream channels and third-party entities. The goal is simple: to map out the PV module supply channels to the U.S. out to 2025 and beyond.
8 October 2024
San Francisco Bay Area, USA
PV Tech has been running an annual PV CellTech Conference since 2016. PV CellTech USA, on 8-9 October 2024 is our second PV CellTech conference dedicated to the U.S. manufacturing sector. The event in 2023 was a sell out success and 2024 will once again gather the key stakeholders from PV manufacturing, equipment/materials, policy-making and strategy, capital equipment investment and all interested downstream channels and third-party entities. The goal is simple: to map out PV manufacturing in the U.S. out to 2030 and beyond.

Read Next

May 15, 2024
US zinc hybrid cathode battery storage manufacturer Eos Energy Enterprises has reaffirmed revenue guidance and expects to achieve a positive contribution margin this year.
May 15, 2024
UK BESS owner-operator Gresham House Energy Storage Fund has put a 50MW/50MWh project into commercial operation in Lancashire.
May 15, 2024
US asset manager Stonepeak has entered Japan’s energy storage market, forming a partnership with CATL-backed developer CHC.
May 15, 2024
The Australian federal government’s 2024-2025 budget includes a major investment in clean energy manufacturing and an energy bill rebate for households.
May 14, 2024
UK battery energy storage system (BESS) developer-operator Statera has submitted a planning application for a 500MW project in Oxfordshire, England.

Most Popular

Email Newsletter