Meet Renaissance Fusion, a Grenoble-based startup that has been working on nuclear fusion for the past few years. The company recently raised $16.4 million (€15 million) 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 of disruptive solutions in energy production and distribution technologies in France and Europe. Grenoble is a highly strategic location enabling them to benefit from We are supported by an environment conducive to the development of nuclear energy, a strong ecosystem such as CEA, and an unmatched talent pool,” Alexis Houssou, founder and managing partner of HCVC, said in a statement.
Unlike most tokamak-based fusion experiments, Renaissance Fusion is working on stellarator reactors. The company is aware of the long and precarious road ahead, as it expects to be able to deliver a small fusion reactor with a capacity of 1 GW by the 2030s. It will not directly operate power plants. Instead, the company will sell its reactors to plant builders and operators.
“We have a very unique technology,” Renaissance Fusion founder Francesco Volpe told me. Instead of designing complex three-dimensional coils to generate the magnetic field, Renaissance Fusion greatly simplifies the process by drawing orbits on cylinders.
After doing some calculations based on the magnetic field you want to generate, the team can determine the coil shape you need. The cylinder rotates on its axis while the device moves side to side to laser engrave tracks on the surface of the cylinder.
The cylinder blocks are then put together to form the reactor. This modularity should help with shipping and logistics. As for the neutrons emitted by the nuclear reactions inside the cylinder, Renaissance Fusion wants to use liquid lithium to create thick walls that would separate the plasma from the outside world.
“We inject a layer of liquid metal. It flows inside the cylinder and is pumped out of the bottom. It’s thick enough to absorb most of the neutrons,” Volpe said.
This liquid metal is also used to extract heat from the stellarator, which can be used to generate steam, which can be used to drive turbines, which can be used to generate electricity.
According to the startup’s founders, Renaissance Fusion is quite innovative in its use of liquid metal. “In commercial fusion, we’re the only company with liquid lithium facing the plasma,” Volpe said.
Currently, the company can produce liquid lithium-based walls as thick as 1 centimeter. It will take a lot of iterations before it can be used for fusion, as Renaissance Fusion estimates it needs to be 30 to 40 centimeters thick.
The company is already considering commercial applications that could be released by the 2030s. For example, Volpe sees Renaissancee Fusion’s coil patterning technology for MRI and energy storage. “Anytime you need strong magnetic fields, large volumes and high precision,” he said.
With today’s funding round, Renaissance Fusion plans to triple its team size to 60 people by the end of 2023. In many ways, this is still early days for Renaissance Fusion. So let’s see how it fares in the next few years.