Scientists have shown that fusion energy can work as a physical process. The open question is whether it can work economically. MIT researchers have introduced a framework that judges the commercial viability of fusion power plants. It examines both the physical inputs required to keep fusion reactions going and the costs of building plants able to compete in energy markets.
Fusion energy joins light atomic nuclei, the same process that powers stars. The reactions create a plasma, a very hot ionized gas usually held by magnets or started by lasers. The aim is abundant energy with good safety and siting options. In 2022 a California facility achieved a reaction that produced more energy than was supplied to the fuel. Private investment has grown, yet major hurdles remain for commercial plants.
Ten parameters for viability
The framework uses ten parameters. The parameters include power density, the efficiency of turning fusion power into a usable product, the durability of conversion components, and measures of costs and returns on invested capital. The method draws on the Lawson Criterion, which sets the temperature, density, and confinement conditions needed for net energy from plasma. That criterion yields plasma Q, the ratio of fusion power produced to the power needed to sustain the plasma. The method is independent of the specific fusion approach used and can be scaled to plants of any size. Both small and large plants must generate more money than they consume to remain viable over time.
The new approach focuses on economic Q, the ratio of capital gained to capital spent. This value must exceed one for basic viability. The parameters work for any fusion method and any plant size. The researchers stress the need for careful cost accounting as funding increases. Early successful plants may later reduce costs through practical experience, as has occurred in other technologies. The framework offers a clear quantitative way to evaluate design choices at this stage.
This study is published in Journal of Fusion Energy.