On a February morning in southern Finland, steam began rising from an unlikely source: a brewery powered by heated sand.
The installation at Nokian Panimo—the country's second-largest craft brewer—represents the first commercial test of technology developed by TheStorage, a Tampere-based cleantech startup that announced €3.6 million in fresh seed funding on April 23, 2026. That may not sound like the sort of capital that typically moves markets, but in the niche world of industrial thermal storage, it's a meaningful bet on an approach that could, eventually, help decarbonize some of the world's hardest-to-clean industries.
Founded just three years ago, TheStorage is commercializing what it calls "Sand-in-Motion" thermal energy storage—ordinary sand, heated to between 800°C and 1,100°C using electricity, then cycled through insulated silos to deliver process heat for manufacturing. The new round, led by Nordic deep-tech firm Voima Ventures, included participation from existing backers Superhero Capital and 2C Ventures, along with newcomer Momentum Partners. That brings the company's total raised to €5.8 million, including a prior €2.15 million round that closed in part with a €1 million injection last October from Business Finland and earlier investors.
TheStorage claims its approach can replace the natural gas boilers and oil-fired furnaces that still dominate industrial heating with a system that stores renewable electricity as heat, cutting both emissions and energy costs. Whether the technology can scale beyond a single brewery—and whether TheStorage can compete in an increasingly crowded field—remains an open question.
The Physics (and the Promise)
Sand isn't exotic. It's cheap, abundant, and thermally stable at high temperatures—qualities that make it appealing as a storage medium. TheStorage heats it to between 800°C and 1,100°C using a patented electric heater, then shuttles the material between two insulated silos. One holds hot sand; the other, cold. During charging, sand moves through the heater. During discharge, it flows past a proprietary heat exchanger that transfers thermal energy to whatever the customer needs: steam (including superheated varieties), thermal oil, hot air, or pressurized water.
The critical distinction, according to the company, lies in how the sand behaves during storage. Static systems—those that heat sand and leave it sitting in a single vessel—suffer from heat loss and inefficient transfer rates. TheStorage's architecture keeps sand motionless while stored, then sets it in motion only when energy is being added or extracted. The result, the company claims, is heat-transfer efficiency up to ten times higher than static alternatives. Round-trip efficiency typically lands between 90% and 98%, a range that would be competitive if validated at scale.
Systems can be configured from 1 to 20 megawatts of power output, with storage capacity ranging from 20 to 500 megawatt-hours. Crucially, charging and discharging can happen simultaneously—a feature that could prove useful for facilities with fluctuating heat demand or those looking to arbitrage electricity prices.
TheStorage also suggests its systems could participate in grid reserve markets, generating additional revenue by providing frequency regulation or other ancillary services. That remains, for now, a projection rather than a proven revenue stream.
A Brewery Pilot—and the Road Ahead
The Nokian Panimo installation went live in February, producing steam for brewing operations. The brewery, which recorded €11.9 million in net sales and 8.3 million liters in volume last year, recently listed on First North, a Nordic growth market. It's a respectable pilot customer, though hardly a steel mill or cement plant—the sorts of energy-intensive behemoths that will determine whether thermal storage can crack the industrial decarbonization puzzle.
TheStorage claims the system can slash energy costs by up to 70% compared to fossil-based heat and cut emissions by up to 90%. Those are company figures, not third-party audits, and the real-world economics will vary widely depending on local electricity prices, fuel costs, and operational patterns.
The new funding will go toward hiring (the company aims to double headcount by year-end, though current LinkedIn data suggests somewhere between two and ten employees), accelerating commercialization, and building out its first full industrial-scale plant before 2027. Target industries read like a who's who of carbon-intensive sectors: food and beverage, textiles, pharmaceuticals, pulp and paper, cement, chemicals, petrochemicals. Collectively, these industries account for an enormous chunk of global emissions. A McKinsey report from December 2024 noted that industrial heat alone represents more than 20% of total global energy consumption, with roughly 80% still derived from fossil fuels.
Which brings us to the competitive landscape. TheStorage is far from alone in chasing this opportunity. California-based Antora Energy raised a $150 million Series B in February 2024, banking on thermal batteries built around carbon blocks rather than sand. Rondo Energy, another U.S. player, announced €75 million in project funding last June and brought a 100 megawatt-hour system online in 2025. There are others, too—each with slightly different technical approaches, each convinced their architecture offers the best path forward.
For TheStorage, the challenge will be proving that its sand-in-motion design offers enough of an edge to win contracts at scale. A single brewery pilot is encouraging, perhaps, but it's hardly definitive. Industrial customers tend to be conservative, risk-averse, and slow to adopt unproven technologies, especially when the stakes involve production uptime and energy reliability.
Still, the funding suggests at least some sophisticated investors believe the approach has merit. Voima Ventures, which led the round, has a track record in Nordic deep tech. Whether TheStorage can translate that backing into commercial traction—and whether heated sand can compete with everything from heat pumps to hydrogen in the messy, fragmented race to decarbonize heavy industry—will become clearer in the months ahead.
For now, the company has its brewery. And a few million euros to figure out what comes next.
