The global transition to renewable energy systems is imperative for climate sustainability. However, nations face significant challenges, including financial constraints, grid vulnerabilities, and dependence on fossil fuels. This study evaluates the feasibility of a 100% renewable electricity scenario for Cuba by 2050, employing a multidisciplinary framework integrating energy modelling (CUBALINDA), sustainability threshold quantification (Integrated SuWi Doughnut Approach), and cross-sectoral impact analysis (Dynamic Synergy Analysis).

Using CUBALINDA—an adaptation of the LINDA framework calibrated for Cuban conditions—a backcasting scenario was constructed based on solar PV, wind energy, and Power-to-X technologies, supplemented by energy storage and green hydrogen production to address renewable intermittency.

The Integrated SuWi Doughnut Approach reveals that while Cuba meets all social sustainability thresholds, it currently operates outside environmental limits regarding renewable energy share and ecological footprint. The Dynamic Synergy Analysis demonstrates that ammonia derived from green hydrogen could replace fertiliser imports, increase agricultural production, and reduce dependence on food imports.

Cuba's energy transition is technically feasible but requires coherent policies, intersectoral integration, and substantial infrastructure investments. Green hydrogen yields significant collateral benefits, fostering energy sovereignty and agricultural revitalisation. By 2050, solar photovoltaic and wind will dominate the energy mix (93 % renewable share), progressively replacing fossil fuels with sustainable biofuels and e-fuels.

Critical challenges include grid modernisation, seasonal supply-demand imbalances, and financing for hydrogen infrastructure, all of which require coordinated policy interventions and innovative financing mechanisms. This study provides a replicable framework for integrated energy-sustainability planning, emphasising the need for decomposition and resilience analyses to optimise transition pathways.