Skeleton Becomes a $1B Unicorn as Siemens Bets Nine Figures on Its AI Data-Center Power Tech

Skeleton Technologies, the Tallinn-based energy storage company, has crossed a $1 billion valuation after a nine-figure strategic investment from Siemens, becoming the latest Estonian tech unicorn.

The investment is worth more than $100 million, though the companies did not disclose the exact figure. Skeleton said the cash will primarily fund an expansion of its US manufacturing footprint and research and development in Silicon Valley, where it plans to invest more than $200 million building out operations close to hyperscaler customers.

Founded 17 years ago, Skeleton develops high-power energy storage systems built on its proprietary Curved Graphene supercapacitor technology. In return for the investment, Siemens secured exclusive rights to sell Skeleton's high-power energy-storage systems to data-center customers, deepening a relationship that already includes the German firm's work automating Skeleton's €220 million SuperFactory near Leipzig.

The bet reflects where AI infrastructure is heading. Global data-center electricity consumption is expected to nearly double from around 485 terawatt-hours in 2025 to 950 terawatt-hours by 2030, according to the International Energy Agency, while electricity use by AI-focused data centers is expected to triple.

The problem is not only total consumption but how AI workloads use power. GPU clusters can swing between power states in milliseconds, creating rapid load swings, peaks, and harmonics that strain both data centers and the grid. Skeleton's systems are designed to manage those fluctuations close to the workload, claiming up to 40 percent energy savings and double-digit improvements in GPU performance.

"AI is scaling faster than the power infrastructure behind it. The constraint is not how many GPUs you can buy, but how much compute you can extract from every GPU and every megawatt available," said Taavi Madiberk, Skeleton's CEO. He has argued that supercapacitors are becoming the new semiconductors — the components that determine how much performance hyperscalers can actually deliver.

For Siemens, the investment is a way to offer data centers a complete package. Peter Koerte, the company's chief technology officer, said Siemens already supplies power gear and design software to data centers and sees the partnership as the missing storage layer. "We don't need the next OpenAI right now, what we need is the next generation of AI, which will primarily operate at the application level," Koerte said. "We need to further expand the infrastructure."

Skeleton says it already works with all the big US cloud firms and expects its systems to soon be deployed across a gigawatt of data-center capacity. The US expansion is aimed at building a fully integrated domestic value chain, from cells to complete power systems.

The deal makes Skeleton one of more than ten Estonian tech companies valued at over $1 billion — a striking concentration for a country of about 1.3 million people. It follows a €33 million first close the company secured in May 2026, which had brought its cumulative venture funding to €392 million ahead of a planned US stock market listing in 2027.

Whether Skeleton's systems can deliver the promised savings at gigawatt scale will decide whether the unicorn tag sticks. But with Siemens as both investor and exclusive distributor, the company has bought itself a front-row seat in the AI infrastructure buildout — and the capital to chase it.