Finnish clean-tech startup TheStorage recently launched its first industrial-scale sand-based thermal storage system. This technology can convert renewable energy into thermal energy stored in sand, providing a solution for industrial heating. According to the company, this innovative technology can help industrial enterprises reduce energy costs by up to 70% and cut carbon emissions by up to 90%.

The concept for this sand-based thermal storage system was first proposed in Finland in 2023, with engineering development commencing in 2024. In January 2026, TheStorage completed the installation of its first industrial-scale pilot unit at a brewery, validating the technology's performance in a real production environment. This system provides the brewery's production line with a fully renewable energy-based steam supply.

Vesa Peltola, the brewery's Production Manager, stated: "Adopting a non-fossil fuel method for steam production is a key step towards achieving a carbon-neutral manufacturing process."

TheStorage's sand-based thermal storage technology can capture electrical energy when supply is abundant and prices are low, converting it into high-temperature thermal energy stored within the sand medium. The stored thermal energy can be dispatched on-demand for industrial processes, unaffected by real-time fluctuations in electricity supply.

Timo Siukkola, CEO of TheStorage, pointed out: "Industrial enterprises have long been seeking viable decarbonization solutions. Now, renewable electricity generation can finally meet industrial heat demand in an environmentally friendly and economical way."

The system operates based on two insulated storage silos, an electric heating unit, and a heat exchanger. Cold sand is conveyed from the low-temperature silo to the electric heater, heated to up to 800°C, and then stored in the high-temperature silo. By circulating the sand through an external heat exchanger, the system achieves a heat transfer efficiency ten times higher than traditional static storage methods.

The stored thermal energy can be released on-demand as steam or thermal oil, providing a stable energy supply capable of quickly responding to changing industrial needs. The system's storage capacity is scalable between 20 and 500 megawatt-hours (MWh), with charging power ranging from 1 to 20 megawatts (MW), depending on the specific industrial application and project requirements. Both charging and discharging operations offer full flexibility.

In Finland, PolarNight Energy commissioned the world's largest sand battery energy storage unit last year - a 1 MW / 100 MWh thermal energy storage system. In November of the same year, the company announced plans to build a new project with double the capacity. Upon completion, it will have a 2 MW thermal output and 250 MWh of storage capacity, becoming the world's largest sand-based thermal energy storage facility.

Previously, in 2022, Polar Night Energy launched the world's first commercial sand-based high-temperature thermal storage system in Kankaanpaa, Finland. That system had a power output of 100 kW and a storage capacity of 8 MWh.