Circular economy as a lever for sustainable energy transition an integrative framework and mechanisms based typology

Despite growing recognition that circular economy practices can act as direct levers for decarbonization, the academic literature has largely treated the circular economy and the energy transition as parallel rather than structurally intertwined processes. Supply-side decarbonization strategies continue to dominate, while the mechanisms through which circular economy practices reduce primary energy demand remain analytically fragmented. No study has yet developed a mechanism-based typology tracing the explicit causal configurations linking circular economy levers to energy transition outcomes under specific carbon lock-in conditions. This study conducts a focused integrative review of 143 peer-reviewed studies indexed in Scopus over the period 2015–2025, structured in accordance with PRISMA guidelines. Studies are coded using a mechanism-oriented extraction grid and subsequently organized into a seven-family typology. Seven mechanism families are identified: energy and material efficiency, waste-to-energy and energy recovery, waste heat recovery and cascading, critical material recycling, industrial symbiosis and system integration, governance and policy mechanisms, and demand-side, sufficiency and behavioral mechanisms, each targeting a distinct dimension of carbon lock-in. Only sub-cluster F1-D is structurally resilient to the rebound effect. All intensity-reduction families require complementary demand governance. Family F5 simultaneously reduces and reinforces institutional lock-in, making it the most governance-sensitive family in the typology. Family F7 represents merely 0.7% of the corpus, establishing behavioral lock-in as the most analytically underdeveloped frontier of the circular economy and energy transition nexus. Circular economy governance instruments must be designed in parallel with technical measures, not sequentially. The seven-family typology provides policymakers and firms with a mechanism-level framework to identify which circular economy levers are relevant to their transition context and which governance complements are required to prevent efficiency gains from being neutralized by rebound dynamics. The typology’s direct and indirect contributions to SDG 7 (affordable and clean energy), SDG 12 (responsible consumption and production), SDG 13 (climate action) and SDG 9 (industry, innovation and infrastructure) are also mapped.