Alva Energy launched with $33 million in Series A funding led by Playground Global, positioning itself as a nuclear energy company focused on boosting power output from the existing U.S. reactor fleet to meet rising electricity demand from AI data centers and other industrial uses. The Cambridge, Massachusetts-based startup said its approach offers a faster and lower-cost path to expanding clean, firm power than building new nuclear plants, with a timeline and cost profile it argues can be competitive with gas-fired generation.
The company plans to “productize” nuclear plant uprates by turning complex retrofit work into standardized, turnkey offerings. Alva’s model centers on replacing steam generators and adding a second turbine generator to increase electrical generation while maintaining or improving safety margins. Alva said it will manage the full uprate lifecycle, including regulatory compliance, procurement, installation, and commissioning, with the goal of reducing risk, shortening timelines, and making repeatable upgrades deployable across the reactor fleet.
Alva estimates its uprates can add 200 to 300 MWe per reactor, roughly comparable to the output of a small modular reactor, with potential to unlock 10 GWe of new capacity across the U.S. grid through the 2030s. The company said its standardized offering is built on technologies with more than 100 reactor-years of operating history and can be deployed as quickly as gas turbines in today’s market, while avoiding carbon emissions.
The Series A syndicate included Segra Capital, NGP, Mercator Partners, and Alumni Ventures, with returning participation from 8VC, Logos, Simon Holmes à Court, and Isabelle Boemeke. Alva also cited earlier backers from its initial funding round, including Gigascale Capital, Safar Partners, Collaborative Fund, Activate Global, and Michael Anders. Pat Gelsinger, a general partner at Playground Global, is joining Alva’s board.
Alva is also pitching an “innovative financing model” in which it works directly with large-scale power consumers, including hyperscalers, and utilities to finance nuclear plant retrofits without increasing costs for residential ratepayers. The company framed this as a way to address a growing challenge for the AI industry, namely, community opposition to new data center development, as consumers face rising electricity costs.
Alva said its team includes engineers and project leaders with nuclear delivery and licensing experience, pointing to prior work on record setting steam generator replacement and reactor design certification timelines. The company said it expects its first projects to come online in five years, and that the new funding will support parallel project development, engineering team growth, and efforts to secure regulatory pre approvals for key uprate methods from the U.S. Nuclear Regulatory Commission.
KEY QUOTES
“America can’t afford to wait decades to build new nuclear generation capacity or for next-generation technologies to meet today’s rising power demands. By upgrading the nuclear infrastructure we already have, we can deliver gigawatts of clean, always-on power to meet the needs of AI data centers, and we can do it without burdening ratepayers with the cost. With our first projects online in five years, this is the fastest, most practical way to expand carbon-free energy capacity in the U.S.”
James Krellenstein, Chief Executive Officer and Co-Founder, Alva Energy
“The biggest obstacle standing in the way of an AI-enabled future isn’t compute, it’s power. Playground invested in Alva because they’re the only nuclear company designed to deliver at the speed, scale and certainty this moment demands. Their approach doesn’t rely on theoretical technologies or distant timelines, it unlocks gigawatts of clean power from existing infrastructure. It’s real, it’s financeable and it’s deployable this decade.”
Pat Gelsinger, General Partner, Playground Global
“Segra Capital has been involved with Alva since its founding because what gives us confidence is not theory–it’s execution. Members of the team have managed multi-billion-dollar nuclear projects, led NRC design certifications, and completed some of the most complex component replacements in the industry. That kind of delivery pedigree is extraordinarily difficult to replicate, and it’s why we’re excited to back Alva’s ambitious goals.”
Arthur Hyde, Partner, Segra Capital Management
“Alva Energy is unlocking the full potential of the existing U.S. nuclear power fleet. By enhancing generation capacity at current plants, they can safely and affordably expand nuclear power before new plants are constructed. Alva’s uprate solution delivers additional nuclear capacity with the cost-effectiveness and speed comparable to combined cycle gas plants. The team’s exceptional project delivery experience, coupled with a standardized uprate design, ensures a thoughtful and secure expansion of U.S. nuclear power production. NGP is proud to support the talented team at Alva.”
Maritza Liaw, Partner, NGP
