Decision makers in the energy sector – ranging from those setting national- or state-level technology policy, to firms deciding which new technologies to invest in, to consumers deciding whether to adopt the new technologies – are all faced with very complex decisions under uncertainty, both in terms of future fossil and non-fossil technology costs and in terms of future climate change policy and climate change related damages. In order to develop and to evaluate strategies for sustainable energy futures society needs to understand both the potential for future technological change; as well as, how that technological change will influence the evolution of the energy system, the economy, and the environment. Over the past two decades, there have been many calls for increased support for energy Research Development and Demonstration (RD&D) from a diverse set of important stakeholders and academics (e.g., American Energy Innovation Council, 2010; PCAST, 1997, 2010; NCEP, 2004; Nemet and Kammen, 2007; Schock et al., 1999). These calls highlight the importance of energy R&D in meeting energy challenges globally and nationally.