Influence of energy management strategies and storage devices on the techno-enviro-economic optimization of hybrid energy systems: A case study in Western Australia

The evolution and technological growth of battery energy storages have added a certain mobility to the global development and dispatch of hybrid renewable systems subsiding the supply uncertainty of these systems arising from the inherent source-intermittency. However, the existing technical diversity among those battery storages calls for the assessment of how different technologies affect an optimal renewable mix and its techno-enviro-economic performance while meeting highly dynamic load demands. This study considers three different elec-trochemical energy storages, namely lead acid, lithium-ion and vanadium redox flow battery systems to be commissioned into stand-alone hybrid energy systems comprising different proportions of solar photovoltaic, wind turbine, and micro gas turbine to serve the electricity demand of an Australian community. Each of these hybrids are subjected to two different energy management strategies, and optimized using non dominated sorting genetic algorithm II method with the multi-objectives of minimizing cost of energy ($/kWh) and life cycle emission (kg CO2-eq/kWh) under a predefined reliability constraint, loss of power supply probability. Moreover, the impacts of different battery technologies and dispatch strategies have been assessed considering different socioeconomic, technical and environmental performance indicators. Results indicate that the hybrid system with cyclic charging strategy gives the lower energy cost with lifecycle emissions slightly higher than the load following strategy options. The vanadium redox flow-based hybrid options offer the lowest cost of energy (0.126-0.187$/kWh) and the lifecycle emissions (46,258-104,664 kg CO2-eq/yr) of all. The sensitivity analysis reveals that the cost of energy of the hybrid options declines at the cost of reliability and lifecycle emissions. This study provides vital information for energy planners to decide which battery technology to choose and under which dispatch strategy it performs better when the overall technical, economic, environmental and social perspectives are in play.