Last Energy
Updated: December 16, 2025
Founder Bret Kugelmass
Country: USA | Funding: $164M (+)
Founded: 2020
Website: https://www.lastenergy.com
Last Energy builds small modular nuclear reactors that can be mass-produced. The company uses an older 20 MW reactor design developed by the government for a merchant ship. Such reactor is designed to operate without maintenance for its entire service life. It will be delivered to site in an all-metal vessel with a six-year supply of uranium. Heat from fission reactions heats the steel and water flowing through pipes outside uses this heat to spin a steam turbine. At the end of its service life, the steel vessel will serve as a waste container, eliminating the need for separate disposal. The company hopes that this approach, combined with advances in manufacturing, will lead to lower cost of nuclear energy. Last Energy is currently building a 5-megawatt pilot reactor and production of a 20-megawatt commercial reactor is scheduled to begin in 2028.
Founded: 2020
Website: https://www.lastenergy.com
Last Energy builds small modular nuclear reactors that can be mass-produced. The company uses an older 20 MW reactor design developed by the government for a merchant ship. Such reactor is designed to operate without maintenance for its entire service life. It will be delivered to site in an all-metal vessel with a six-year supply of uranium. Heat from fission reactions heats the steel and water flowing through pipes outside uses this heat to spin a steam turbine. At the end of its service life, the steel vessel will serve as a waste container, eliminating the need for separate disposal. The company hopes that this approach, combined with advances in manufacturing, will lead to lower cost of nuclear energy. Last Energy is currently building a 5-megawatt pilot reactor and production of a 20-megawatt commercial reactor is scheduled to begin in 2028.
