energy-storage.news
Sep 23, 2026
Compressed air energy storage (CAES): yet to deliver on promises, can A-CAES go one step further?
AI-summarised brief · reviewed before publication
Hydrostor is advancing a new variant of compressed‑air energy storage called advanced CAES (A‑CAES), which captures and reuses the heat generated during compression instead of venting it. A‑CAES stores air in engineered hard‑rock caverns with a water‑head piston, eliminating the need for natural‑gas combustion during discharge. The system operates at 75 bar and requires a large water volume—about 150 m³ per MWh—to create the head. Hydrostor aims to make CAES easier to deploy and more efficient than traditional salt‑cavern CAES projects, such as China’s 600 MW Huai’an plant.
💡 Why It Matters
- · By reclaiming waste heat and using water‑piston mechanics, A‑CAES could lower operating costs and reduce carbon emissions, offering a cleaner, scalable alternative to conventional grid‑scale storage.
