Stellarators as a Fast Path to Fusion

Abstract

The enhancement of the atmospheric concentration of carbon dioxide is doubling every forty years. Options must be developed for energy production that do not drive carbon-dioxide emissions and can be fully deployed within a few doubling times. Unit size and cost of electricity are only relevant in comparison to alternative worldwide energy solutions. Intermittency, site specificity, waste management, and nuclear proliferation make fusion attractive as the basis for a carbon-free energy system compared to the alternatives. Nonetheless, fusion will not be an option for deployment until a power plant has successfully operated. A critical element in a minimal time and risk program to operate a fusion power plant is the use of computational design as opposed to just extrapolation. The importance of minimizing time and risk is so great that ideally more than one concept would be pursued. Unfortunately, only the stellarator has an empirical demonstration of the reliability of computational design through large changes in configuration properties and scale. The cost of computational design is extremely small, even compared to the present scale of the fusion program. Adequate time for the development of ideas that increase attractiveness and reduce risks requires a quick initiation of design studies of fusion power plants, but this is counterbalanced by the natural resistance to change. As will be shown, that sentiment is contrary to both the needs of society and the status of the science; a shift in the priorities of the fusion program to societal needs is required. The construction cost of a power plant may seem great relative to the risk, but a fusion program of tens of billions of dollars a year would be approximately one percent of the annualized financial benefit of success.