Skeleton Technologies, an energy storage company based in Estonia and Germany that we met at TBB, has closed the first part of its pre-IPO funding round at €33 million. This brings its total venture capital raised to €392 million.
New investors are Axon Partners Group, SmartCap, and Taiwania Capital, while existing investor CBMM also joined. The company plans to close a larger funding round before its US IPO in 2027.
“As AI infrastructure continues to scale, reliable, high-performance power solutions have become critical. This funding round brings additional strategic partners to the table and strengthens our ability to deliver the next generation of power solutions that cut AI data centre energy consumption by 40%, increase computing power by 40%, and enable faster power grid connection,” says Taavi Madiberk, CEO and co-founder of Skeleton Technologies.
He co-founded Skeleton with Oliver Ahlberg in 2009 to develop supercapacitor-based energy storage systems for AI data centres and grid infrastructure. Supercapacitors charge and discharge in milliseconds, unlike regular batteries.
In 2025, data centre electricity use rose by 17%, with AI centres growing even faster. The International Energy Agency expects data centre electricity use to double by 2030, and AI-specific demand to triple. The biggest challenge is connecting to power grids quickly enough to keep up.
Skeleton’s main product, the GrapheneBBU, replaces traditional lithium-ion battery backups in data centre power racks. Its system reacts in milliseconds, smoothing out power spikes from GPU clusters during AI training and enabling faster grid connections without oversizing the infrastructure.
Skeleton says its technology can cut data centre energy use by 40% and boost computing power by 40%. This year, the company delivered millions of supercapacitor cells to a major American hyperscaler, and more clients are testing the technology.
Skeleton’s competitors include EnerSys and Vertiv, which offer traditional battery backup systems, as well as newer companies like Capacitech Energy. Skeleton stands out with its graphene-enhanced supercapacitor design, made at scale in Germany, and a one-gigawatt SuperBattery factory being built in Finland.
The fresh funding will help Skeleton expand into the US market, including setting up production capacity there. It will also support further manufacturing growth in Europe as the company prepares for its 2027 IPO.
