Alva Energy

About Alva Energy

Alva Energy is a nuclear technology company focused on increasing the power output of existing nuclear reactors in the United States. Founded in 2023 by CEO James Krellenstein, COO Garrett Wilkinson, and CTO W. Robb Stewart, PhD, the Cambridge, Massachusetts-based startup aims to address the rising electricity demand from sectors like AI data centers by productizing nuclear plant upgrades, known as "uprates". The company's core service involves transforming complex retrofit projects into standardized, turnkey offerings. This approach is designed to make the process of boosting reactor output faster, more predictable, and more cost-effective than building new nuclear generation capacity.

Alva Energy manages the entire uprate lifecycle, which includes regulatory compliance with the U.S. Nuclear Regulatory Commission (NRC), procurement of long-lead items, installation, and commissioning. The company's methodology centers on replacing steam generators and adding a second turbine generator, which can add 200–300 megawatts of capacity per reactor. This process utilizes technologically mature, regulator-ready methods with a proven history of safe operation, adapting techniques from successful uprates performed globally. By standardizing the scope and delivery, Alva converts these upgrades into repeatable and financeable infrastructure projects. The company's goal is to unlock a total of 10 gigawatts of new power from the existing U.S. reactor fleet.

The business model is structured to work directly with utilities and large-scale power consumers, such as hyperscale data centers, to finance the retrofits. This off-balance sheet financing approach allows utilities to engage in high-value power purchase agreements (PPAs) without imposing increased costs on residential ratepayers, a key consideration amid community opposition to rising electricity prices. In February 2026, Alva Energy announced it had launched with $33 million in Series A funding. The round was led by deep-tech venture capital firm Playground Global, with participation from Segra Capital, NGP, and others. Pat Gelsinger, former CEO of Intel and VMware, joined Alva's Board of Directors as part of the investment, bringing experience in scaling complex technology infrastructure.