Conceptions of the aims and characteristics of DEMOs are evolving in response to world issues. Many areas are important in these considerations: two particularly important, and technically related, ones are examined here.
Firstly, in the recent Strategic Energy Technology plan (SET plan) in the EU, approaches to technological development that could substantially change the future energy supply system were investigated. For fusion, this included considering how fusion development could be accelerated, particularly whether construction of a DEMO plant could start earlier than is normally assumed, perhaps before full exploitation of ITER. This is described in the technology map of the EU SET plan as an Early DEMO, or EDEMO. In this context, reconsidering the balance of the arguments between a steady-state and a pulsed design for EDEMO is motivated by the possibility that a sufficiently reliable and efficient current drive system may not be available on the necessary timescale.
Secondly, the context for a fusion power plant, and consequently for DEMO, is set by the assumed applications, amongst which hydrogen production is an important possibility. Although this is a very different issue from pulsed operation of a fusion plant, it may be crucial in setting the framework in which a fusion plant operates. Both issues have the potential to radically change the view of what a DEMO plant should do.