Energy storage
Molten Salt Storage
Definition
Molten salt storage is a thermal energy storage technology using mixtures of nitrate salts (commonly sodium and potassium nitrate) kept liquid at high temperatures — roughly 290–565°C — in insulated tanks. In the standard two-tank configuration, "cold" salt is heated by a solar receiver or heat exchanger into a hot tank and later pumped through a steam generator to discharge. Heat losses can be as low as about 0.5°C per day.
References
Supports definition and framing.
Supports definition and framing.
Overview
What it means
It is the dominant storage approach for concentrating solar power (CSP), decoupling solar collection from power generation and enabling dispatchable renewable electricity for hours after dark. Variants are being developed for industrial heat and grid-scale electricity storage.
How it is used
CSP tower and trough plants integrate molten salt tanks for evening generation; new applications include retrofitted fossil boilers and Carnot-battery concepts.
Why it matters
Cheap, long-duration storage is the missing piece of high-renewable grids; molten salt is one of the few proven technologies storing many hours of energy at utility scale.