Throughout history, scientific advancement has been dependent upon advances in the technologies of research. However, branches of research that today rely on Research Infrastructures (RIs) such as accelerators require technological investments so large that multination collaborations are required to fund them. Modern accelerator science also has massive (and increasing) energy needs, yet the very provision of secure, equitable, clean and cost effective energy is one of the greatest sustainability challenges facing society. Modern energy provision systems are fundamental to development, yet also constitute one of the greatest threats to sustainability via their contribution to environmental degradation and climate change. This paper works from a premise that any new proposal for investment in an RI should credibly demonstrate that it would deliver more value than cost to society. As our understanding of the negative impacts of energy use grows, the demonstration of overall value creation has become more complex; it must now include consideration of an RI’s ‘energy system footprint’. Programs to reduce the energy footprint can help address this delicate balance. This paper uses experiences in the development of the European Spallation Source (ESS) in Sweden to demonstrate how credible programs to improve the energy performance of an RI can take form.