Economic study on the key aspects required for a commercial fusion power plant design based on EUROfusion-DEMO to become commercially viable

To use fusion as a source for energy it is important to understand where future fusion plants would fit into the energy markets of the latter half of the century. The European demonstration power plant (EU-DEMO) is the first step to understanding this but a commercially viable successor is needed to fit into the energy sector. This study builds on the outputs of the EU-DEMO gate review to revise previous assumptions, with the ultimate goal being a set of commercially feasible concepts that guides research to fill identified gaps from EU-DEMO. Three designs were used to investigate a commercial fusion plant using specifications from previous work such that there is a tokamak design with limited technological extrapolation from DEMO, a tokamak design with significant advancement over DEMO and finally an advanced alternative concept, a stellarator. These designs cover different possibilities post EU-DEMO allowing for a study of the commercial viability of the various paths to a commercial power plant. This study of the commercial viability of a plant will look into the standard electrical production as well as an alternative which is hydrogen production. Hydrogen is looked at because it is an alternative energy option to electricity that has many uses in future markets. This paper demonstrates that to reach a commercially attractive fusion plant after DEMO, design improvements with the aim of cost reduction are required in addition to simply scaling up a plant in net electric output. In order to get a truly cost competitive plant, advanced concepts such as a steady-state tokamak or a stellarator need to be used, where the stellarator design was economically comparable to the advanced tokamak design. • Fusion designs like EU-DEMO need to be iterated upon to become cost competitive. • Three designs of varying technological readiness were investigated for commercial viability. • The systems code PROCESS was used to optimise these designs and study their levelised costs. • Hydrogen production was investigated as an alternative route to commercial viability. • A key finding was that scaling EU-DEMO up in size is insufficient for commercial viability. • Improvements to the design technological capability alongside scaling in size was required.