A scientific breakthrough has been made in Ordos, North China's Inner Mongolia autonomous region, where researchers have turned ordinary sand into a large-scale thermal energy storage system.

The project was led by the Ordos Laboratory and focused on developing key technologies for high-temperature industrial thermal storage.

It achieved full-process operation of a megawatt-hour (MWh)-scale solid particle thermal storage pilot device at the Dalad Industrial Park in Juungar Banner. This milestone marks a major step forward in using sand as a thermal energy "battery" in real-world settings.

The pilot is based on the pioneering "sand thermal battery" concept developed by the Tsinghua University team of Wei Fei and Zhang Chenxi.

Using high-power electromagnetic induction, the system rapidly converts surplus or low-cost electricity – such as wind, solar, or off-peak grid power – into thermal energy. This energy is then stored in specially treated sand particles, forming a high-temperature reservoir that can later supply heat or be converted back into electricity, helping to stabilize intermittent renewable energy.

The innovation overcomes key technical challenges such as slow heat transfer in sand and energy loss from coil heating. The resulting system transforms common and low-cost granular materials into a thermal storage unit operating at 600–1500C, with an energy density of 120–450 Wh/kg and a charge-discharge efficiency above 90 percent.

The successful operation of this pilot system proves the technical viability of high-temperature solid particle thermal storage and lays the groundwork for scaling up to 100 MWh and even gigawatt-hour-level industrial demonstration projects in the future.