Transformations of the energy supply sector towards EU’s net-zero goal

Abstract This study explores the implications of technology availability constraints on the decarbonisation pathways of the EU power sector, drawing on scenario results from five European energy supply models: MEESA, LIMES, ENERTILE, ACSG, and OSeMBE. The analysis evaluates how limiting the deployment of key low-carbon generation technologies, namely carbon capture and storage (CCS), nuclear power, bioenergy, solar photovoltaics, and wind energy, affects the electricity generation mix, emissions reduction, investment needs, and power system costs by 2030 and 2050. Results within the model ensemble indicate that variable renewable energy sources (VRE), wind and solar, are indispensable for deep decarbonisation. Constraints on solar or wind power substantially increase electricity generation costs and require major shifts in technology portfolios, often resulting in greater reliance on remaining renewable options or fossil fuel generation with CCS. The unavailability of CCS leads to higher system emissions and increased investment in renewables and storage. In contrast, removing nuclear or bioenergy has a more moderate impact, though some regional effects are significant. All models show that achieving ambitious emission reductions in the power sector remains technically feasible under individual technology constraints, but the mitigation effort shifts across generation technologies, and system costs rise considerably in low VRE futures. Policy implications include the need for robust support for wind and solar deployment, cross-border system integration, flexible technologies, and backup capacity. The findings underscore the value of a diversified technology portfolio, strategic infrastructure investments, and EU-level coordination to preserve cost efficiency and ensure stable power system performance under uncertainty in future technology availability.