Technology

Concentrated Solar Thermal with molten-salt storage

High-temperature solar heat captured by a heliostat field, stored in molten salt, and released on demand as firm power or process heat — day and night.

Concentrated solar thermal receiver tower Concentrated solar thermal receiver tower
How it works

From sunlight to dispatchable power

01

Heliostat field

Thousands of individually tracked mirrors concentrate sunlight onto a central receiver at the top of a tower, raising the working fluid to temperatures approaching 565°C.

02

Molten-salt storage

Hot molten salt flows from the receiver into insulated tanks. Storage duration scales by adding more salt and steel — the cheapest part of the plant. 8–14 hours is standard.

03

Steam turbine dispatch

When power or heat is needed — day or night — hot salt generates steam to drive a turbine. The synchronous generator provides grid inertia at no extra cost.

The duration wall

Why CST, not batteries

A battery's cost rises almost in a straight line with the hours it must run. Molten-salt storage adds hours simply by adding salt to a larger tank — the cheapest part of the plant. Batteries win the sprint of one to four hours; thermal storage wins the marathon of eight to fourteen hours and beyond.

Advantage

8–14 h storage

Thermal storage scales cheaply with duration — salt and steel, not chemistry. A mining load runs all night, and that overnight block is where this technology delivers.

Advantage

Synchronous inertia

The steam turbine delivers grid strength that PV and batteries cannot — frequency response and fault current included at no extra cost.

Advantage

Process heat

Stored solar heat can be delivered directly as high-temperature process steam — cheaper than electrify-then-reheat for many mineral processing applications.

Advantage

Diesel displacement

Lowest total cost as storage duration and heat demand grow — plus synchronous grid strength and diesel/gas displacement at remote sites.

Track record

A proven, operating fleet

China's tower-CSP fleet represents approximately 1.7 GW across 27 plants as of end-2025 (SolarPACES / CSTA China Blue Book). These are not demonstration units — they are commercial plants delivering power to the grid, with years of operating data.

~1.7 GW
Installed capacity
27
Operating plants
8+ years
Commercial operation

Want to understand the economics for your site?

We offer a no-cost desktop opportunity screen — CST benchmarked against alternatives with a clear go / no-go verdict.