A smart energy systems planning framework for high-renewable transitions in emerging energy systems: Application to Ghana

This study addresses the challenge of planning high-renewable energy transitions in rapidly developing energy systems facing increasing energy demand, fossil-fuel dependence, structural constraints, and limited flexibility. To this end, it develops and applies an integrated planning framework grounded in the Smart Energy Systems concept to evaluate pathways towards high shares of renewable energy under realistic system constraints. Ghana is used as a representative case study to demonstrate the applicability of the proposed framework in a Sub-Saharan African context. The analysis combines the characterisation of the national energy system, assessment of renewable resource potential, analysis of socio-economic drivers, and construction of a validated reference model. Four baseline high-renewable scenarios and two cost-optimised scenarios were evaluated using cost minimisation subject to ε-constraint bounds on electricity imports and exports. This enabled the identification of feasible combinations of photovoltaic, wind, and hydropower generation, complemented by battery and flywheel storage, while maintaining realistic electricity exchange balances. The results show that the selected transition pathway can reduce carbon dioxide emissions by approximately a factor of three, decrease fuel consumption from 131.7 TWh to 75 TWh annually, increase the renewable share of electricity to 95%, and expand renewable generation from 7.7 TWh to 40.2 TWh per year. The findings provide practical insights for renewable integration, storage planning, regional electricity trade-offs, and low-carbon transition strategies in Sub-Saharan Africa and comparable contexts.