In this perspective, an overview of the key challenges and opportunities in the design of new energy systems is presented. Recent shifts in the prices of natural energy resources combined with growing environmental concerns are creating a new set of challenges for process design engineers. Due to the massive scale and impact of energy conversion processes, some of the best solutions to the energy crisis lie in the design of new process systems which address these new problems. In particular, many of the most promising solutions take a big-picture approach by integrating many different processes together to take advantage of synergies between seemingly unrelated processes. This paper is an extended version of a paper published as part of the proceedings of the 8th International Conference on the Foundations of Computer-Aided Process Design (FOCAPD 2014) Adams (2014). (c) 2015 Elsevier Ltd. All rights reserved.