Planning alternatives under divergent futures: Linking transformative scenario design with bottom-up modelling and distributional impact assessment to quantify inequalities in electricity affordability

The clean energy transition promises substantial societal benefits but risks reinforcing existing inequalities if its costs and benefits are unevenly distributed. While distributional impacts have gained increasing attention in climate and energy policy analysis, many modelling frameworks remain limited in their ability to represent socioeconomic heterogeneity, bottom-up technology choices, and citizen-centred transition pathways, particularly in electricity systems with high shares of variable renewable energy. As a result, such frameworks may misrepresent electricity affordability, conceal regressive impacts, and support policy recommendations that overlook vulnerable households. This study addresses this gap by integrating bottom-up modelling with distributional impact assessment, using the Greek power sector as a case study. We develop alternative transition scenarios based on storylines informed by the concept of energy citizenship and future-world narratives. These scenarios are embedded within the OSeMOSYS modelling framework to assess alternative system-planning evolutions, costs, and emissions under conditions of heightened uncertainty and external shocks. Model outputs are subsequently combined with household budget survey data to evaluate how costs are allocated across income groups, accounting for heterogeneity in electricity consumption patterns. Our results show that decentralised, solar-oriented transition pathways could significantly improve electricity affordability compared with centralised alternatives by 2050, reducing electricity bills as a share of total income (2.4% versus 4.6%) and substantially narrowing affordability gaps between the lowest and highest income groups (6.3% versus 11%). Overall, our findings demonstrate that least-cost electricity system designs do not necessarily align with socially equitable outcomes and provide insights for designing just and inclusive energy transitions.