Determination of the Optimal Installed Capacity Ratio of Solar and Wind Power Plants in a Hybrid Energy Complex

Efforts to mitigate climate change have driven the decarbonization of the global economy, particularly the energy sector, accelerating the integration of renewable energy sources into power systems. However, the variability and limited predictability of wind and solar power generation increase flexibility requirements and may lead to renewable energy curtailment due to generation surpluses, grid constraints, and operational or market-related factors. Key mitigation measures include energy storage systems, hybrid energy complexes, interregional interconnections, demand-side management, and optimization of the generation mix. Unlike existing approaches that focus on optimizing individual system components according to economic or reliability criteria, this study investigates how the ratio of installed wind and solar capacities affects the power and energy capacity requirements of an energy storage system (ESS). The proposed approach normalizes actual hourly generation profiles to identify the capacity ratio that minimizes ESS requirements. A hybrid energy complex comprising wind and solar power plants and an ESS operating in parallel with the grid in baseload mode is analyzed using statistical and factor analysis, mathematical modeling, and computational methods. The results indicate that the optimal solar-to-wind installed capacity ratio ranges from 0.75 to 1.25. At a ratio of 1.0, the required ESS energy capacity decreases by 39-41%, while the required storage power decreases by 30–45%, compared with a standalone wind power plant. These findings demonstrate the potential to reduce energy storage system construction or leasing costs through optimal wind–solar capacity allocation.