Comply with Renaissance fusion, a Grenoble-based start-up that has been working on nuclear fusion for the past few years. The company recently raised $16.4 million (€15 million) in funding in a seed round led by Lowercarbon Capital.
Several European investors also participated in the round, such as HCVC, Positron Ventures and Norssken.
“We are proud to support Francesco Volpe and his team in the emergence and industrialization in France and Europe of a breakthrough solution in energy production and distribution technologies. Grenoble is a highly strategic location allowing them to benefit from a favorable environment for nuclear energy development, a strong ecosystem such as the CEA and an unparalleled pool of talent,” said Alexis Houssou, founder and managing partner at HCVC. a statement.
Unlike most nuclear fusion experiments based on tokamaks, Renaissance Fusion is working on a stellarator reactor. The company is well aware that it has a long and windy road ahead as it expects to be able to ship a small nuclear fusion reactor with a capacity of 1 GW in the 2030s. It wouldn’t run power plants directly. Instead, the company would sell its reactors to plant builders and operators.
“We have a technology that is quite unique,” Francesco Volpe, founder of Renaissance Fusion, told me. Instead of designing complicated three-dimensional coils to generate a magnetic field, Renaissance Fusion greatly simplifies this process by drawing traces on a cylinder.
After some calculations based on the magnetic field you want to generate, the team can determine the shape of the coils you need. The cylinder rotates around an axis as a device moves left and right to laser-engrave tracks on the surface of the cylinder.
Image Credits: Renaissance fusion
Cylinder blocks are then assembled into a reactor. This modularity should help when it comes to shipping and logistics. As for the neutrons emitted by the nuclear reaction inside the cylinder, Renaissance Fusion aims to use liquid lithium to create thick walls that separate the plasma from the outside world.
“We inject a layer of liquid metal. It flows around the inside of the cylinder and is then extracted at the bottom. It’s thick enough to absorb most neutrons,” Volpe said.
This liquid metal is also used to extract heat from the stellarator, which can be used to create steam, which can be used to drive turbines, which can be used to generate electricity.

Image Credits: Renaissance Fusion /
According to the founder of the startup, Renaissance Fusion is quite innovative with the use of liquid metal. “We are the only one in commercial fusion where the liquid lithium is directed to the plasma,” Volpe said.
Currently, the company can make liquid lithium-based walls that are 1 centimeter thick. It will take many iterations before it can be used in nuclear fusion, as Renaissance Fusion estimates it would need a thickness of 30 to 40 centimeters.
The company is already thinking about commercial applications that could be released before the 2030s. For example, Volpe believes that Renaissane Fusion’s coil cartridge technology can be used for MRI and energy storage. “When you need a strong magnetic field, large volume and high precision,” he said.
With today’s funding round, Renaissance Fusion plans to triple the size of its team to 60 people by the end of 2023. In many ways, these are still the early days of Renaissance Fusion. So let’s see how it plays out over the next few years.