Thermal Storage (Heat and Cold)
📘 Technology description
Thermal storage systems store energy in the form of heat or cold, using materials with high heat capacity or phase-change properties. The main types include:
– Water-based thermal storage – short-term heat accumulation tanks.
– Molten salt storage – high-temperature systems used in Concentrated Solar Power (CSP) plants.
– PCM (Phase Change Material) systems – utilize latent heat during melting/solidifying.
– Underground or soil storage – seasonal heat storage for district heating networks.
✅ Advantages
– Very low unit cost of stored energy (most economical storage type).
– Can be integrated with heating and industrial systems.
– Long lifespan and high reliability.
– No use of critical materials, minimal environmental impact.
– Can also operate as cold storage (e.g., for cooling systems).
⚠️ Limitations
– Stores energy as heat, which not all applications can directly use (conversion to electricity reduces efficiency).
– Limited conversion efficiency when converting heat back to electricity (20–40%).
– Large physical size for long-term storage.
– Requires good thermal insulation and stable environmental conditions.
🏭 Applications
– District heating and cogeneration systems – heat buffering for cities and municipalities.
– Industry – waste heat recovery.
– Solar power plants (CSP) – storing heat in molten salts.
– Buildings and data centers – cold storage for energy optimization.