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Finland is harnessing the unexpected power of sand to decarbonise industrial heat – a major “blind spot” in global emissions.
Industrial heat production is one of the largest and hardest-to-solve sources of carbon emissions, accounting for around one fifth of the world’s total energy consumption.
Hot steam is required across many sectors, from food production to chemical processing, and most of that heat is currently generated from fossil fuels (around 80 per cent comes from oil and gas).
The issue with heat demand
Electrifying industrial heat is no easy feat due to the variable availability of renewable energy. Industry requires a constant supply of heat throughout the year, whereas renewables such as wind are reliant on suitable weather conditions.
It led Finnish cleantech startup TheStorage to try capturing clean electricity when it is abundant and cheap and convert it into high-temperature heat that is then stored in sand. This stored heat can be used in industrial processes regardless of real-time electricity availability.
“Companies have wanted to decarbonise for years, but viable solutions simply weren’t available,” says Timo Siukkola, CEO of TheStorage.
“Finally, renewable energy generation can meet industrial heat demand in a way that’s both ecologically sound and economically practical.”
How does sand-based heat storage work?
The principle of sand-based heat storage is relatively simple. Heat is stored in ordinary sand using two insulated silos, as well as an electric heater and a heat exchanger.
Cool sand is moved from a cold silo to an electric heater, where it reaches temperatures of up to 800°C. The heated sand is then stored in a hot silo, where energy is efficiently retained in stationary sand.
“By circulating the sand through an external heat exchanger, the system delivers steam with up to tenfold higher heat transfer efficiency compared to conventional static storage systems,” TheStorage explains.
“The stored heat can be released on-demand as steam or thermal oil, providing stable power that can be quickly adjusted to match demand.”
TheStorage began testing the idea in January 2026, launching the first industrial-scale pilot at a brewery in Finland. The startup says its solution could cut energy costs by up to 70 per cent and carbon emissions by up to 90 per cent.
It argues that fossil-free industrial heat is key in achieving EU climate goals, which aim for a 90 per cent reduction in emissionsby 2040 and full carbon neutrality by 2050.