Kraftblock high-temperature heat storage

What it is

Kraftblock's storage is a modular thermal battery for factories. It charges from renewable electricity through a power-to-heat element, or directly from hot exhaust and waste heat, and discharges as steam, hot air, thermal oil or hot water. The company states an output range from 50 °C to 1,300 °C. Units come in container sizes of 10, 20 and 40 feet as well as stationary modules; reported modules hold roughly 30 to 60 MWh each.

How it works

The storage medium is a granulate, patented by Kraftblock and made largely from recycled steel slag. Air or another heat-transfer medium flows through the packed granulate to load and unload heat. Because the material is a ceramic-like solid rather than a salt, it tolerates temperatures far above the roughly 500 to 600 °C ceiling of many molten-salt and concrete systems, and Kraftblock says heat can be held for up to two weeks.

Why it stands out

The two reference projects show both main uses. At PepsiCo's Lay's crisp plant in Broek op Langedijk in the Netherlands, wind power is converted into heat at 800 °C, stored, and delivered as thermal oil at about 300 °C to the fryers. The first two modules total 70 MWh; three more were planned, and the full scheme targets a 98 per cent cut in process-heat emissions, with the first stage around 51 per cent. At Tata Steel's sintering plant in Jamshedpur, India, reported in March 2026, two storage units of up to 20 MWh capture waste heat from the cooling section and return it to the process, with projected savings of about 22,000 tonnes of CO2 and 110 GWh of natural gas a year.

Where you meet it

Behind the walls of food, steel and chemical plants, typically where gas boilers or furnaces would otherwise run continuously. The business case improves wherever electricity prices swing widely, because the storage can charge when power is cheap and supply heat around the clock.

Sources

• CleanThinking: Kraftblock decarbonises crisp production at PepsiCo
• Solarserver: Tata Steel project
• Kraftblock: company website