Toward a Provincial Energy Trilemma Index (PETI): A Systematic Review and Framework for Subnational Energy System Assessment

The growing complexity of energy systems has increased the need for frameworks that can assess performance beyond traditional national indicators. While research on the Energy Trilemma is expanding, most studies focus on national and cross-country analyses, with limited attention given to the provincial and subnational energy systems where disparities in infrastructure, accessibility, and sustainability conditions are most often pronounced. This study fills that gap by creating a Provincial Energy Trilemma Index (PETI) framework. This framework allows for a localized assessment of energy security, energy equity, and environmental sustainability. Using the PRISMA systematic literature review approach, the study analyzed 67 peer-reviewed articles from the Scopus database related to Energy Trilemma assessments, sustainability transitions, composite energy indices, and decentralized energy systems. The review used thematic synthesis and indicator frequency analysis to identify common indicators, assessment methods, and operational assessment analysis relevant for provincial use. The findings highlighted the electrification rate, electricity affordability, renewable energy share, supply reliability, carbon emissions, and energy efficiency as the most common and applicable indicators for provinces. The review also showed that existing Energy Trilemma studies are methodologically fragmented and not well-localized, limiting its capacity to capture decentralized energy dynamics and spatial disparities across provinces and island systems. In response, the study suggests PETI as a multidimensional and provincially adaptable framework that combines well-founded and measurable indicators across the three main dimensions of the Energy Trilemma. The framework offers a basis for provincial benchmarking, sustainability monitoring, localized assessment and evidence-based energy planning within decentralized and diverse energy systems.