A Silicon Valley startup is developing a hot rock battery that could be the next big thing in energy storage — and it’s coming to Europe. The giant brick toaster is the brainchild of San Francisco-based Rondo Energy. The startup believes it could be a cheap, scalable way to decarbonise industries making everything from steel to soap.
Rondo has already raised over $100mn from investors including Microsoft, mining conglomerate Rio Tinto, and Saudi Arabia’s oil and gas giant Aramco. Speaking of Microsoft, Bill Gates’ Breakthrough Energy Ventures was Rondo’s first major investor. And this week, the climate tech fund opened its coffers once more.
Rondo has secured €75mn from Breakthrough Energy Catalyst, and the European Investment Bank. Founded in 2020, Rondo has already proven its technology in the US and Thailand. Armed with the fresh funds, it looks to take on the European market.
In Europe, “we see very strong tailwinds to the adoption of our technology,” said Eric Trusiewicz, CEO of Rondo Energy. The company is planning to build three batteries at three very different factories in Denmark, Germany, and Portugal. In Denmark, the hot rock battery will be used to produce cleaner biogas.
In Germany, it will power a Covestro chemical plant that produces polymers. In Portugal, it will power a yet-to-be-announced food and beverage facility. How does the hot rock battery work? Rondo’s hot rock battery uses renewable energy to power a network of electrical resistanc.