Google is now an investor in nuclear fusion. German startup Proxima Fusion announced a 411 million euro financing round at a 2.4 billion euro valuation, with Google and German utility RWE joining as strategic investors, Reuters reports. The round was led by XTX Ventures and East X Ventures; Google’s individual stake was not disclosed.
Proxima, spun out of the Max Planck Institute, is building stellarator-based fusion with the goal of Europe’s first commercial plant in the 2030s. For Google, the logic is not next quarter’s power bill. It is the recognition that AI’s appetite for electricity has no natural ceiling, and that every hyperscaler now needs a portfolio of energy bets stretching from solar to small modular reactors to, now, fusion.
Energy is the last bottleneck
The AI buildout’s constraints have moved in sequence: first GPUs, then memory, then land and grid connections. Power is the terminal constraint, the one you cannot manufacture more of by adding a fab. That is why the same week Amazon borrowed $25 billion for data centers, Google bought optionality on the physics that could eventually feed them. Fusion remains unproven at commercial scale, and 2030s timelines have slipped before; the size of the check tells you it is a hedge, not a plan of record.
What to watch
Watch whether other hyperscalers follow with fusion stakes this year, whether Proxima hits its next hardware milestone on schedule, and how European regulators treat fusion licensing, the quiet variable that decides whether the 2030s target is credible. Meta took the more conventional route in Alberta, funding a dedicated natural-gas plant rather than betting on unproven physics, a hedge of a different kind.
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