Terrafold raises EUR 140M for industrial heat storage

Terrafold, the Amsterdam company that stores electricity as heat in crushed basalt, raised EUR 140 million in a round led by Temasek with Breakthrough Energy Catalyst, Just Climate, and Invest-NL. The pitch is stubbornly physical. Charge when power is cheap, heat rock to about 1,000 degrees Celsius, then release the energy as industrial process steam for plants that still burn gas because an electric boiler wrecks the economics. Food, chemicals, paper, and textiles are the named target sectors. Four systems are already running, two at Dutch food sites, one at a Belgian chemical plant, and one at a Swedish paper mill. The largest holds 92 megawatt-hours thermal and can deliver 8 megawatts of steam. The Swedish site has fourteen months of operation, and the operator reported a 71 percent gas reduction. Manufacturing near Rotterdam currently supports about eight units a year, with expansion toward roughly forty. The order book runs to eleven systems into 2028. CEO Sanne de Vries is keeping the company out of the United States because cheap gas wrecks the arbitrage. Higher-temperature research toward 1,400 Celsius aims at cement and glass later. Competitors include Rondo, Antora, and Kyoto Group. This is infrastructure fundraising dressed as climate tech, which is the only wardrobe that fits. More in our startups section. Written with the usual Younes Bekrar desk standards. Primary reporting and docs: Terrafold, Breakthrough Energy, TechCrunch, Crunchbase News.

What is happening with industrial decarbonization?

Here is the plain-English frame before the details. Amsterdam's Terrafold raised EUR 140M led by Temasek to expand basalt heat batteries that turn cheap power into process steam for food, chemicals, paper, and textiles. Four systems are already running. For adjacent coverage, start with our startups category or the author bio for Younes Bekrar.

Basalt, steam, and the industrial heat problem

Industrial process heat is where a lot of decarbonization slideware goes to die. Factories need steam on a schedule. Gas boilers are paid for and understood. Electricity is often too expensive per unit of energy to replace those boilers directly in Europe. Terrafold's answer is not a prettier boiler. It is a thermal battery made of crushed basalt that absorbs cheap electricity as heat near 1,000 Celsius and gives it back as steam. See also Terrafold.

Basalt is the point. Engineered storage media can work and still lose on capex. Crushed rock is abundant, cyclic, and boring in the best way. The hard engineering sits in insulation, high-temperature heating elements, and the heat exchanger that produces controlled process steam. De Vries has described that exchanger work as a major development sink in prior company commentary around the product, and the funding story still orbits that industrial reality rather than a consumer app narrative.

Food, chemicals, paper, and textiles are sensible first markets because they eat a lot of steam and already speak the language of uptime. They also tend to sit in European power markets where wind and solar create hours of very cheap electricity. The arbitrage only works if you can charge hard in those hours and discharge on the plant's rhythm.

I like that Terrafold does not market itself as erasing the gas boiler on day one. Hybrid operation is the adult product shape. Keep gas for ugly price weeks. Displace most of the burn the rest of the time. Procurement committees approve hybrids faster than purity plays that strand existing assets.

Ninety-two megawatt-hours thermal with 8 megawatts of steam on the largest running system is the scale anchor. That is big enough to matter to a mill and small enough to still be a manufacturing story rather than a national grid story. Climate tech that cannot name a deployed joule makes me nervous. This one can.

The Swedish paper site's fourteen months and 71 percent gas reduction are the receipts. Not zero gas. Not a lab claim. An operator-reported cut after real seasons of price weather. That 71 percent should travel with every fundraising headline.

What EUR 140M is supposed to buy

Temasek leading, with Breakthrough Energy Catalyst, Just Climate, and Invest-NL alongside, is a capital stack that reads industrial and patient. Breakthrough Energy Catalyst in particular tends to show up when hardware needs scale capital rather than seed vibes. Invest-NL's presence fits an Amsterdam company building near Rotterdam. Background: Breakthrough Energy.

Manufacturing is the bottleneck de Vries is funding into. About eight units a year near Rotterdam is not a global flood. Expanding toward roughly forty is how you turn an order book into installed steam. Eleven systems into 2028 means demand is ahead of the current factory drumbeat. That gap is exactly what a EUR 140 million round is for if the company stays disciplined.

Higher-temperature research at about 1,400 Celsius is the optionality tranche. Cement and glass need hotter process heat than food steam. De Vries has been careful in public framing to keep that in the research bucket rather than the product brochure. Good. Premature cement claims are how thermal storage startups lose trust.

Staying out of the United States is a strategic tell I respect. Cheap US gas weakens the spark spread that makes rock batteries pencil. Europe's renewable-heavy price collapses are the hunting ground. Competitors may chase America anyway. Terrafold is choosing the market where its physics meets its power market.

Rondo, Antora, and Kyoto Group are the competitive set worth keeping on one slide. Rondo's brick approach, Antora's carbon blocks with a path back toward electricity, and Kyoto Group's molten salt work at lower temperatures are different bets on medium and product shape. All of them are still in early unit-count territory as a category. That means the market is open and unforgiving at the same time.

I measure this category by factories running, not by keynote watts. Four Terrafold systems across Dutch food, Belgian chemicals, and Swedish paper beat a hundred rendered animations. The raise should be judged on whether Rotterdam output actually climbs toward that forty-unit ambition without quality falling over.

The risks I am watching after the applause

Policy and market design can compress the arbitrage. Hourly prices, grid fees, and capacity mechanisms all change the value of soaking surplus renewable power. If Europe redesigns industrial power charges in ways that flatten cheap hours, thermal batteries feel it. De Vries's public posture has been that the business can tolerate a thinner spread than today's. Investors should still model uglier markets than the pitch deck.

Execution risk is manufacturing and commissioning, not tweet sentiment. Moving from eight units a year toward forty is a plant operations problem, supplier problem, and field service problem. Thermal systems that under-deliver steam become stories plant managers tell each other forever.

Customer concentration and sector focus cut both ways. Food and paper can build a beautiful reference list and still leave you short of cement-scale climate impact until 1,400 Celsius research becomes product. That is fine if the company says so. It is fatal if the marketing skips ahead.

Competition will not wait. Rondo and Antora have their own capital and geographies. Kyoto Group presses from the molten salt side. The winner may be regional rather than global. Terrafold's Europe-first, no-US stance accepts that framing.

For Skarvonix readers in climate investing, the diligence questions are blunt. Are the eleven ordered systems converting on schedule into 2028. Does the Swedish-style gas reduction show up at the Belgian and Dutch sites under different price weather. Does the Rotterdam expansion hit rate without quietly redefining what a unit means.

My close is unromantic on purpose. EUR 140 million for crushed basalt heat batteries is a bet that industrial steam can chase cheap electrons without waiting for a miracle boiler. Four running systems, a 71 percent gas cut at a Swedish paper site, and a CEO who will not pretend US gas prices cooperate make this one of the more grounded climate hardware raises on my desk. Now they have to build the factory cadence to match the order book.

Related reading on Skarvonix: our startups category, the authors directory, and more from Younes Bekrar.

Primary sources and further reading: Terrafold, Breakthrough Energy, TechCrunch, Crunchbase News, Y Combinator.