The small modular nuclear company X-energy keeps racking up funding.
The Maryland-based developer raised a $700 million Series D round, it announced today, led by existing investor Jane Street. X-energy said it plans to use the funds to expand its supply chain and commercial pipeline; it has an orderbook of more than 11 GW, which the company said equates to roughly 144 SMRs.
“The success of this financing round allows us to deepen partnerships with critical deployment partners and invest in a robust and reliable supply chain to successfully deliver projects with our customers,” CEO J. Clay Sell said in a statement. The company is developing a small reactor that it is pitching as a reliable option for powering data centers and factories.
The round was oversubscribed. Additional first-time investors include Ark Invest, Corner Capital, and Galvanize. Existing investors Ares Management, Emerson Collective, NGP, and Segra Capital Management also participated.
This is just the latest example of how much capital is available to companies offering clean firm power for data centers. But it wasn’t always this way. Until the AI boom was well underway, the advanced nuclear space struggled somewhat to raise funds; the unproven technology and years-off deployment timelines seemed to make investors skittish.
Today, however, hyperscalers like Amazon — a major partner of X-energy’s — are anticipating needing more power than the grid can easily deliver. This is prompting major investment as well as new funding approaches for yet-to-be-commercialized technologies like enhanced geothermal, advanced nuclear, and long-duration energy storage.
And while hyperscalers have tended to take the lead, a growing slate of institutional investors are beginning to get involved in the funding boom as well.
The Amazon relationship
X-energy’s growth so far has been bolstered by its relationship with Amazon. The tech giant’s Climate Pledge Fund anchored the company’s last fundraise, a $500 million Series C-1 with participation from NGP Energy Capital, and the University of Michigan, among others. That round was ultimately upsized in February.
But Amazon is also X-energy’s largest customer. In 2024, Amazon signed deals with both X-energy and the power company Energy Northwest, which is the utility partner for X-energy’s first-of-a-kind plant in Washington state. Amazon agreed to fund the project’s development, licensing, and construction; Daniel Gross, a director at Amazon’s Climate Fund, told Latitude Media at the time that capital at a nuclear project’s early stages is “the shortfall in the market,” but it’s what ultimately enables an orderbook.
Just last month, Amazon and X-energy announced plans to triple the size of that first 320-megawatt plant. They’re now planning for a 960-MW plant powered by 12 reactors. Amazon aims to start construction by 2030, and hopes to generate electricity sometime “in the 2030s.” It will be dubbed the Cascade Advanced Energy Center.
While the Washington project is first in line, Amazon and X-energy have plans to develop more than five GW of X-energy projects across the U.S. before 2039. And X-energy also has corporate deals with Dow Chemical, as well as the state-owned Korea Hydro & Nuclear Power.
X-energy is also developing a facility to manufacture its proprietary TRISO-X advanced nuclear fuel.
