Magnetic confinement fusion

A safe, sustainable and inexhaustible source of energy: a milestone on the path to decarbonization.

Commonwealth Fusion Systems (CFS)

 Commonwealth Fusion Systems (CFS) was spun out of MIT and is collaborating with MIT’s Plasma Science and Fusion Center to leverage decades of research combined with the innovation and speed of the private sector to bring fusion energy to market. CFS has assembled a world-class team working to design and build fusion machines that will provide limitless, clean fusion energy to combat climate change. Eni Next led CFS’ Series A fundraising round to support a company uniquely positioned to deliver the fastest path to commercial fusion energy.

Technological challenge

Fusion is the process that happens in the stars when two hydrogen nuclei fuse and release an enormous amount of energy. The fuel for fusion would be forms of hydrogen and as a result the fusion process would produce zero carbon. The promise of commercial fusion energy would mean a clean, safe, and limitless power source for the world. 

 CFS’ approach to fusion is magnetic confinement, which has been well-studied and proven for decades around the world. However, no one has yet to create an experiment that produces net-gain energy, the key step to prove fusion can work as a power source. CFS is developing game-changing high field magnets that will allow them to design and build significantly smaller and lower-cost fusion power plants. First, they will use these magnets to design and build the world’s first fusion device that will produce net-gain energy, called SPARC. SPARC will pave the way for the first commercially viable fusion power plant, called ARC. Eni will support CFS with the computing power of its HPC5, sited in Ferrera Erbognone (Italy), in order to speed up plasma numerical simulation and engineering design.


The world needs a fundamental new source of clean energy to support our quality of life while combating climate change. CFS is on a mission to bring clean, cheap, and limitless fusion energy to market on a timeline that impacts climate change

Bob Mumgaard, CEO at CFS

In 2021 an important milestone for CFS

In September 2021 CFS has successfully completed the test aiming to demonstrate the operation of the innovative magnet for plasma fusion confinement, for the first time made with HTS (High Temperature Superconductor) technology. The technology under testing is key in the framework of magnetic fusion research, as it represents a fundamental step to create the conditions for controlled fusion, making possible its use in future demonstration plants. Studying, designing and building machines that can operate in physical reactions similar to those taking place at the core of the stars is the technological goal that the greatest minds in the world of energy research are striving for. 

The extraordinary result obtained during the test once again demonstrates the strategic importance of our research partnerships in the energy sector and consolidates our contribution to the development of game changer technologies.

Claudio Descalzi, Eni's CEO

The test concerned the superconducting technologies and it showed the possibility of maintaining the magnet in the superconducting regime with a high stability of all the fundamental parameters for its use in a fusion power plant. The innovation will contribute to a significant reduction in plant costs, ignition and maintenance energy of the fusion process and in the general system complexity, nearing the time and reducing the effort to build a demonstrative plant that will produce more energy than that required to maintain the fusion process (net energy production plant). 

On the basis of this important achievement, CFS confirms its roadmap and intends to build the first experimental device SPARC by 2025, followed by the first demonstration plant ARC, that could start feeding energy into the grid over the next decade, according to schedule. SPARC will be built by assembling a total of 18 identical HTS magnet coils (similar to the one tested), in a toroidal configuration (a doughnut shape named “tokamak”) to generate a magnetic field with the strength and stability necessary to contain a plasma of hydrogen isotopes at temperatures of around 100 million degrees, at which the fusion of atomic nuclei can occur with the release of a very high quantity of energy.