Revisiting energy efficiency

Abstract In this this Vignette, leading experts advocate for a resurgence of interest in energy efficiency, placing a renewed emphasis on its strategic importance within energy transitions. In the current context of geopolitical instability, efficiency assumes heightened urgency as a rapid, cost-effective means to reduce exposure to energy price shocks and enhance energy security. By lowering demand, increasing system flexibility, and supporting more resilient and diversified energy systems, energy efficiency is a critical ‘first fuel’ in managing both short-term disruptions and long-term transitions. Energy efficiency has the potential to push transformative change through dynamic and systems-oriented strategies across research, policy, and practice. Such strategies must embed efficiency within broader societal goals – encompassing planetary boundaries and wellbeing – while ensuring that measures deliver synergies including energy security, public health, affordability, competitiveness, and responsible growth. New experiments and scenarios are needed to advance knowledge on potential efficiency pathways. Participatory methods in relation to energy poverty, justice, and sufficiency can help ensure its central role remains legitimate, accountable, and socially grounded. Alongside these societal dimensions, sections of the Vignette also emphasise new potentials enabled through greater electrification, AI, and material resource management, while recognising associated rebound effects or efficiency-induced growth. Energy efficiency provides critical buffering against systemic disruptions in future societal transitions. Strategic policy interventions and financing mechanisms are required to align efficiency with both energy-system goals and wider societal objectives to foster enhanced resilience and wellbeing within ecological limits.