Vast Solar Pty Ltd. and Sage Geosystems Inc. (Sage) announced a memorandum of understanding (MOU) to evaluate global opportunities to integrate concentrated solar power (CSP) generation and long-duration energy storage (ES) deep in the earth to supply clean, dispatchable baseload electricity.

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Wind and solar are intermittent power producers. A more significant share of these sources in the power generation mix lowers emissions but can create challenges for grid operators matching fluctuating demand with available supply. Clean, renewable geothermal as a long-duration storage solution shows promise, offering improved energy stability and predictability, but is still in its nascency.

Vast Solar and Sage aim to pair CSP and ES to deliver renewable baseload power at a reduced capital cost through technology integration and other synergies. This hybridization—combining CSP with ES—at solar power generation sites is expected to enhance availability, capacity, and reliability with long-duration energy storage.

Vast Solar’s CSP technology works by concentrating sunlight to heat sodium as it passes through receivers; heat is transferred from sodium to the molten salt heat transfer fluid and stored in hot salt tanks. The resulting heat can be converted into steam and then electricity as needed.

Sage, a transformative geothermal development company, is developing innovative energy storage solutions deep in the earth, including pressure storage (called EarthStore) and geothermal storage. Sage’s geothermal storage system (called Battery+™) both stores and generates energy from the earth’s heat, so the resulting efficiency is > 200%.

With an overall objective of developing a sustainable power sector through advancements in long-duration storage, there is a strong collaboration rationale between Vast Solar and Sage.

Management Comments

Craig Wood, Chief Executive Officer of Vast Solar, said: «Hybridizing power generation assets has the potential to deliver something greater than the sum of its parts. We are excited to work with Sage to supplement CSP with long-duration geothermal energy storage technologies to optimize renewable baseload power generation.»

Cindy Taff, Chief Executive Officer of Sage, said: «We are excited to work with the team at Vast Solar as we explore new and innovative ways to advance the widespread deployment of long-duration storage solutions globally. Integrating CSP with storage deep in the earth could be exactly what’s needed to drive greater deployments of renewables in the power mix.»

Vast Solar is an Australian developer of concentrating solar thermal power technology. Its innovative modular tower solar array combines the best elements of molten salt towers and parabolic trough systems to deliver the world’s lowest-cost, dispatchable, renewable energy for hot, dry climates.

In October 2019, the Company was awarded the International Energy Agency’s prestigious SolarPACES Technical Innovation Award for the world’s most innovative concentrated solar thermal power technology, and it was shortlisted in 2022 as one of Bloomberg New Energy Finance’s Pioneers.

Vast Solar is currently developing two CSP projects in Australia: the 30MW VS1 in Port Augusta, South Australia; and the 50MW VS2 baseload solar hybrid in Mount Isa, Queensland.

Sage is a rapidly growing business dedicated to the advancement and widespread deployment of geothermal technologies, including storage and baseload power generation. Founded in 2020, Sage brings a team with a proven track record of technology development and deployment globally. Sage is unique in that they are innovating in both the well(s) and power plant design, to deliver cost-effective energy storage and geothermal solutions utilizing off-the-shelf oil and gas industry equipment and technologies.