Reliability and dispatchability improvement of a hybrid system consisting of PV, wind, and bio-energy connected to pumped hydropower energy storage

Conventional electrical power plants require peak load units with high reliability and dispatchability in case of a sudden increase in demand, while base load units should generate constant power without interruption. However, some renewable energy sources may not be reliable because of fluctuations in natural sources and variations in electricity demand. This study addresses the issue of a mismatch between supply and demand in conventional electrical power plants by designing a hybrid renewable energy system (HRES) that includes a photovoltaic (PV) system, wind turbines, pumped hydropower energy storage, and a bio-energy power plant. The HRES aims to increase reliability and dispatchability during peak periods and reduce renewable energy loss. A novel operational strategy and several newly designed techniques are proposed, and many-objective optimisation models considering the technical, economic and environmental perspectives were developed. Comparing all the design techniques, the most competitive technique showed a 6 % increase in terms of system reliability, a 15 % reduction in renewable energy loss, and a levelised cost of energy reduction from 0.22 $/kWh to 0.13 $/kWh. In addition, the most competitive hybrid system design could cover up to 98.3 % of total electricity demand with high reliability. With regard to the environmental benefits, the greatest amount of greenhouse gas emission saved by considering this study is 2.6 x 107 tons. Eventually, by considering renewable energy sources' technical specifications, such as source dispatchability, designers can gain more economic benefits from making use of such sources.