Role of Fusion Energy in a Sustainable Global Energy Strategy

Fusion can play an important role in sustainable global energy because it has an available and unlimited fuel supply and location not restricted by climate or geography. Further, it emits no greenhouse gases. It has no potential for large energy releases in an accident, and no need for more than about 100 years retention for radioactive waste disposal. Substantial progress in the realization of fusion energy has been made during the past 20 years of research. It is now possible to produce significant amounts of energy from controlled deuterium and tritium (DT) reactions in the laboratory. This has led to a growing confidence in our ability to produce burning plasmas with significant energy gain in the next generation of fusion experiments. As success in fusion facilities has underpinned the scientific feasibility of fusion, the high cost of next-step fusion facilities has led to a shift in the focus of international fusion research towards a lower cost development path and an attractive end product. The increasing data base from fusion research allows conceptual fusion power plant studies, of both magnetic and inertial confinement approaches to fusion, to translate commercial requirements into the design features that must be met if fusion is to play a role in the world's energy mix; and identify key R and D items; and benchmark progress in fusion energy development. This paper addresses the question, ''Is mankind closer or farther away from controlled fusion than a few decades ago?'' We review the tremendous scientific progress during the last 10 years. We use the detailed engineering design activities of burning plasma experiments as well as conceptual fusion power plant studies to describe our visions of attractive fusion power plants. We use these studies to compare technical requirements of an attractive fusion system with present achievements and to identify remaining technical challenges for fusion. We discuss scenarios for fusion energy deployment in the energy market