While much of the cleantech spotlight falls on batteries and electric vehicles, a Finnish startup is focusing on a quieter but enormous challenge: industrial heat. TheStorage has raised €3.6 million in seed funding to scale a technology that stores energy in moving sand and helps factories move away from fossil fuels.
The round was led by Voima Ventures, with participation from Superhero Capital, 2C Ventures and new investor Momentum Partners. With the latest raise, total funding now stands at €5.8 million.
The startup was founded in 2023 by Olli Hannula, Timo Siukkola, Heikki Hannula, and Esko Kulju. Its thermal storage system converts electricity into heat, stores that energy in sand, and releases it when needed. By acting as a buffer between fluctuating renewable supply and constant industrial demand, the company aims to make cleaner heat both reliable and affordable.
Instead of relying on expensive materials or complex chemistry, it uses sand as the storage medium, a low-cost, durable and widely available resource. The company says the system can lower industrial energy costs by up to 70% compared with fossil-based alternatives. It does this by allowing customers to buy electricity during cheaper hours and use stored heat later when prices rise.
This flexibility is increasingly valuable as power markets become more dynamic. Rather than consuming energy only when needed, factories can plan around spot prices and reduce exposure to volatile fuel markets.
Environmental gains are equally significant. TheStorage says emissions can fall by as much as 90%, offering heavy industry a route to cut carbon output without paying a green premium.
The technology is already being tested in real-world conditions. In January, TheStorage commissioned a pilot facility at Nokian Panimo, Finland’s second-largest craft brewery. The system generates steam for brewing operations, demonstrating how thermal storage can integrate with existing production environments.
Direct competitors include Polar Night Energy, Rondo Energy, and Antora Energy. TheStorage’s differentiation lies in its sand-in-motion architecture and its focus on steam generation for food and manufacturing processes, as demonstrated at the brewery pilot.
The company plans to use the capital to accelerate commercial growth, hire key talent and build toward its first full industrial-scale plant.
