Nuclear has always had a branding problem. Too serious, too slow, too busy explaining itself to people who already decided how they feel. Last Energy does not debate. It documents. Founded in 2020 as the commercial spinout of the Energy Impact Center, the company came from a blunt realization Bret Kugelmass reached after hundreds of Titans of Nuclear conversations and years of field research. The physics worked. The spreadsheets didn’t. So instead of inventing new atoms, they rebuilt the business.
This week, Last Energy closed an oversubscribed $100M Series C led by Astera Institute, with participation from JAM Fund, Gigafund, The Haskell Company, AE Ventures, Ultranative, Galaxy Interactive, and Woori Technology Investment. Total capital raised now sits at $163M. Capital like this does not show up for science fair trophies. It shows up for execution. Jed McCaleb does not invest in optimism. He invests in systems that can run unattended and still hit their numbers.
Last Energy designs, finances, builds, owns, and operates micro-modular nuclear plants, then sells power under long-term PPAs. No asset dumping. No handoffs. The PWR-20 delivers 20 MWe, fits on 0.3 acres, runs at 95% uptime, and moves from factory to operation in roughly 24 months. Standard PWR fuel. Less than 4.95% enrichment. Closed-cycle air cooling. Manufacturing discipline instead of construction roulette. The innovation lives in throughput, repeatability, and accountability.
The commercial traction is already loud. 80+ microreactors contracted across Europe. Poland, the UK, Romania. $18.9B+ in contracted power sales over 42-year lifetimes. 40 units aligned to data centers that need baseload power the way lungs need oxygen. In Texas, a 200-acre site in Haskell County is staged for 30 reactors aimed directly at hyperscale demand the grid cannot politely absorb.
Regulators are not being outrun. They are being worked with. A DOE Reactor Pilot Program selection. A signed Other Transaction Agreement. Fuel secured. UK regulators confirming a credible path toward a 2027 site license decision. Texas A&M–RELLIS hosting the PWR-5 pilot with criticality targeted for 2026. Progress looks like this when adults stay in the room.
Behind the scenes, the bench is real. Bret Kugelmass setting direction. Daniel Yates bringing board-level pattern recognition. Michelle Brechtelsbauer shaping strategy. Ryan Duncan navigating Texas policy. Adam Lenarz pushing projects through licensing reality, not theory. This Series C is not a victory lap. It is a down payment on industrial patience, the kind that compounds quietly until the lights stay on.
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