Compressed Air Storage Redux – LightSail and Hydrostor

Compressed air storage solutions like LightSail and Hydrostor are being revisited for grid applications. LightSail, a Silicon Valley startup, failed due to unrealistic disruptions in the energy storage sector. Hydrostor, a Toronto-based company, is gaining attention for its compressed air energy storage approach. Unlike LightSail, Hydrostor acknowledges the limitations of existing technologies and processes, avoiding exaggerated claims. Their system involves moving water between underground and above-ground reservoirs to store energy, resembling pumped hydro solutions. However, Hydrostor's claim of requiring less water for the same energy output raises skepticism as it contradicts basic physics principles. The use of water in their system maintains air pressure for efficient turbine operation but limits the choice of storage locations to avoid erosion. Despite some operational facilities, Hydrostor faces challenges related to cavern construction costs, risks, and site requirements. The company's approach offers an alternative to traditional pumped hydro storage but raises questions about its efficiency claims and practicality in real-world applications.