Cost targets for incorporation of fusion in a future decarbonized US electric grid

Commercial fusion plants will need sufficient economic performance to secure a major role in future electricity grids. Using an electricity system capacity expansion model with hourly resolution, we determine the value of various fusion reactors, especially pulsed tokamaks, as members of a least-cost, net-zero-CO2 electric grid in the eastern United States. The value per unit of additional capacity depends on the plant's operational parameters, the cost of competitor technologies, and the existing quantity of fusion power. In a given scenario, a plant's value is most strongly predicted by its variable cost of operation and maintenance (VOM cost) per net MWh-electric, which may be driven by costs of component replacement, e.g. the blanket and divertor . To reach 50 GW of net fusion electrical capacity (1/12th of average system load), plant capital costs per kW of net electric capacity must be less than $3000 to less than $7200, depending on the VOM cost of the plant and the cost of competitor technologies. Adding a multi-hour thermal storage system to a plant could increase the fusion core's value by 5% to 15%. Initial fusion plants would compete with fission, and at higher capacity penetrations would compete with gas with carbon capture and storage, solar, wind, and batteries.