Last Energy Raises $40M Series B to Accelerate Micro-Nuclear Deployment

Last Energy, a developer of micro-nuclear power plants, has closed a $40 million Series B funding round led by Gigafund, with participation from the Autodesk Foundation and several family offices. With this close, Last Energy has now raised a total of $64 million in capital since its founding in 2019.

Last Energy is focused on developing and deploying micro nuclear reactors designed to produce approximately 20 megawatts of electric power (MWe). The term “micro” indicates that this reactor is much smaller than traditional nuclear power plants, which typically produce hundreds or even thousands of megawatts of power.

Last Energy’s power plants, sold under the PWR-20 brand, are designed to be modular and mass-manufacturable. This capability turns on its head the history of nuclear power plant construction, which was characterized by custom-built, large-scale plants with long development timelines. Typical construction times for nuclear plants in the US have historically been in the range of 6 to 10 years with most reactors – 83% – taking less than a decade to build. 

By simplifying the design and construction process, Last Energy aims to deliver its first micro-nuclear plant by 2026, a timeline that would be considered aggressive by industry standards. Last Energy is headquartered in Washington DC and over the past year has nearly doubled its headcount to 70 full-time employees.

“2024 has been a monumental year for Last Energy so far,” said Bret Kugelmass, the founder and CEO of Last Energy. “In the last eight months we released a new prototype, demonstrated our fabrication and transport capabilities, nearly doubled our headcount, and accelerated commercial growth. Closing our Series B was the next step to unlocking key milestones as we continue down the path toward commercial operations.”

The PWR-20 reactor is constructed from a series of prefabricated modules that can be assembled on-site, much like a LEGO kit. This approach not only reduces the time required for deployment but also significantly cuts down on costs, making nuclear power more accessible to private industrial customers. Unlike traditional reactors that are integrated into the public grid, Last Energy’s microreactors are intended for direct use by industrial clients, bypassing the need for complex grid upgrades.

Last Energy’s business model centers on owning and operating its micro-nuclear plants at customer sites. This strategy allows for faster deployment by avoiding lengthy approval processes typically associated with connecting to the public electrical grid. The company’s microreactors are designed to be fully operational within 24 months of deployment.

Last Energy has announced that it has reached commercial agreements for 80 micro-nuclear units, a sharp increase from the 34 units it secured in 2023. Of these 80 units, 39 are for data center developers, a sector that has seen a growing demand for reliable, continuous power to support energy-intensive operations like artificial intelligence and cloud computing.

“Data centers and heavy industry are trying to grapple with a very complex set of energy challenges, and Last Energy has seen them realize that micro-nuclear is the only capable solution,” added Mr. Kugelmass. “More than ever, data centers need technologies that can simultaneously provide energy abundance, ensure energy security, and enable decarbonization. Nuclear power is the only resource that can check all of those boxes on paper, but it will only be feasible if nuclear development becomes faster and more affordable in practice. Last Energy is doing that by miniaturizing, modularizing, and productizing nuclear plants, which is critical to unlock nuclear energy at scale.”

“We are excited to support Last Energy as they trailblaze a new era in clean and reliable energy,” said Ryan Macpherson, the director of climate innovation and investment at the Autodesk Foundation. “By drastically simplifying the design-construction-operations process, leveraging technology and talent from Autodesk, Last Energy’s approach to micro-modular nuclear power has the potential to fundamentally change how we think about energy production — offering a rapid, scalable, and economically viable solution to decarbonize heavy industry.”

According to the International Atomic Energy Agency, nuclear power capacity could increase by as much as 82% by 2050, with small modular reactors (SMRs) like Last Energy’s PWR-20 playing a key role. Last Energy has an ambitious goal of deploying 10,000 units over the next 15 years.

As Last Energy continues to scale, it faces competition from other companies developing small modular reactors and microreactors. Last Energy’s competitors include Oregon-based NuScale Power which specializes in SMRs; Washington-based TerraPower which focuses on advanced nuclear technologies; Maryland-based X-energy which is developing high-temperature gas-cooled reactors; California-based Oklo which is focused on compact fast reactors; and Rolls-Royce SMR, a UK-based company developing small modular reactors with a focus on the European market.

Gigafund was founded in 2017. It was established by Luke Nosek and Stephen Oskoui. The firm focuses on backing transformative companies with long-term potential, particularly in industries like space exploration and energy.

San Francisco-headquartered Autodesk Foundation, the philanthropic arm of Autodesk, invests in early-stage ventures with the potential for large-scale, positive social and environmental impact, especially those that align with Autodesk’s expertise in design and engineering software.