CMBlu Energy, the German deep-tech company developing non-lithium long-duration energy storage, has reached unicorn status, crossing the €1 billion valuation threshold following a €50 million initial close of its Series C financing with participation from Samsung Ventures. All existing investors, including STRABAG SE, also joined the round.
The milestone reflects accelerating commercial validation as data centers and utilities seek dependable, multi-hour energy solutions at scale. CMBlu is the sole inventor of SolidFlow, a new class of non-lithium long-duration energy storage engineered for high-energy, multi-hour applications using non-flammable, water-based electrolytes and proprietary solid energy storage materials. The initial close of the Series C will support manufacturing scale-up and accelerate early commercial deployments in Europe and the United States.
SolidFlow is designed to deliver ten hours or more of dispatchable energy, addressing one of the most urgent structural constraints limiting hyperscale data center growth — how to secure dependable, multi-hour capacity as electricity demand outpaces grid expansion. The technology decouples power from energy capacity, enabling cost-effective scaling and avoiding the supply chains associated with foreign entities of concern for customers in the United States. CMBlu has secured a 5 gigawatt-hour framework agreement from European utility Uniper, a deployment equivalent to powering a 1 gigawatt data center for five hours or a 500 megawatt data center for ten hours, covering the full overnight window when solar generation drops to zero. Founded in 2014 and headquartered in Alzenau, Germany, the company employs more than 250 people, including more than 150 scientists and engineers.
Samsung Ventures described CMBlu’s technology as an industry-leading approach to scaling sustainable, long-duration energy storage that positions the company as a key enabler of the global energy transition. CEO Constantin Eis emphasized that SolidFlow’s combination of inherent safety, streamlined permitting, and resilient localized supply chains addresses critical needs for customers operating data centers and industrial facilities that require energy reliability around the clock and under real-world conditions. The Series C capital will allow CMBlu to scale its automated gigafactory in Alzenau while advancing plans for additional facilities in the United States and Greece.
CMBlu’s achievement of unicorn status reflects broader investor conviction that long-duration energy storage will become foundational infrastructure for the AI era, where data centers require continuous power availability that cannot be guaranteed by solar or wind generation alone without robust storage buffers capable of covering multi-hour windows of low or no generation.
KEY QUOTES:
“Our SolidFlow technology is redefining energy storage by combining inherent safety with a streamlined permitting pathway — enabling faster, more predictable deployment at scale. Customers powering critical operations need energy they can count on through the night and under real-world conditions while maximizing efficiency.”
Constantin Eis, CEO, CMBlu
