Techno-economic and environmental impact assessment of a hybrid renewable energy system employing an enhanced combined dispatch strategy

Developing countries face challenges in maintaining a reliable power supply due to factors such as ageing infrastructure and rapid urbanization. Relying on backup diesel generators during outages is not only ecologically hazardous but also economically inefficient. Integrating multiple renewable sources with conventional energy systems is crucial to meeting growing energy demands and reducing carbon emissions. This study assesses dispatch strategies for optimal operation in hybrid renewable energy systems (HRES) connected to an unreliable national grid (GRD). An enhanced combined dispatch (ECD) strategy is introduced for effective energy distribution, considering load demands, energy resource availability, and grid unreliability. Compared to load following (LF) and cycle charging (CC) strategies, the ECD strategy proves superior, resulting in an optimized HRES configuration with a 248 kW solar PV array, a 2 kW wind turbine (WDT), a 22 kW biogas generator (BGG), a 92 kW diesel generator (DiG), and a 658 kWh battery storage (BSS). Achieving a low Levelized Cost of Energy (LCOE) at 0.148 USD per kilowatt-hour and a Net Present Cost (NPC) of 1.99 million USD. Adopting the ECD strategy also exhibits substantial reductions in CO₂, CO, SO₂, and NO_x emissions when compared to CC and LF. ECD achieves approximately 25% lower CO₂ emissions, 34% lower CO emissions, and a 40% reduction in SO₂ and NO_x emissions. These findings highlight the ECD strategy's potential for effective, economically viable, and environmentally conscious energy solutions, particularly relevant in developing nations like Nigeria, where Hybrid Renewable Energy Systems could play a crucial role in the energy sector.