US Patent 12,130,086 B1 covers a thermal storage battery that stores energy as heat inside a sand–graphite core. It converts electricity from solar, wind, or the grid into thermal energy, and is configured in particular for drying agricultural and food products — one of the most energy-intensive processes in farming.
The system consists of a stainless-steel battery core shell, a thermal storage mixture of sand and graphite, multiple heating elements distributed through the core, and a heat-extraction pipe that carries the stored heat out — all enclosed in layered thermal insulation to minimise losses.
Compared with electrochemical batteries, the design offers long-duration storage at temperatures up to 800°C using abundant, low-cost, environmentally benign materials. Beyond drying, the same principle serves general process heat, space heating, and water heating across industrial, commercial, and household settings.
For a plain-language walkthrough of the three key design ideas — heat isolation valves, distributed heating rods, and the insulation system — read Part 7 of the Sand Battery saga. The story of how the patent’s approval was discovered is in Part 8.