This paper addresses the influence of policy in system recovery, after a cycle of hype and disappointment. The processes that lead to hype and disappointment and their impacts on the trajectory of emerging technologies have been studied, both by the sociology of expectations and the socio-technical transition literatures (Van Lente et al, 2013: Bakker et al, 2012; Geels and Raven, 2007). Research that investigated the conditions that lead to recovery after disappointment found that continuity of policy support was a critical factor (Ruef and Markard, 2010; Melton et al, 2016). But support may not always be maintained, since policy actors can also be affected by disappointment and stop regarding the technology as contributing to social and economic goals. This can be damaging for the emerging system, since it simultaneously reduces the resources provided, and the legitimacy towards other actors (Kivimaa and Kern, 2016; Konrad et al, 2012).

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