Feasibility of hydrogen hybrid energy systems for sustainable on- and off-grid integration: An Australian REZs case study

The escalating effects of climate change and the finite nature of fossil fuels underscore the imperative for transitioning to renewable energy. This study assesses the feasibility of hybrid energy systems that harness renewable sources, such as solar and wind power, alongside hydrogen technologies and solid-state lithium-ion batteries in diverse energy landscapes. Concentrating on five of Australia's renewable energy zones (REZs)- Broken Hill in New South Wales, Murray River in Victoria, Darling Downs in Queensland, Riverland in South Australia, and North East Tasmania-the research employs the Hybrid Optimization Model for Multiple Energy Resources (HOMER Pro) microgrid software. This software optimizes the sizing of system components to ascertain the most cost-effective configurations for each REZ, considering varied scenarios, including resource availability and demand patterns. The findings indicate that Broken Hill and Murray River exhibit the lowest levelized cost of energy (LCOE) for off-grid and on-grid configurations, respectively, at $0.32/kWh and $0.030/ kWh. Conversely, North East Tasmania has the highest LCOE for both configurations, at $0.38/kWh and $0.034/ kWh, respectively. Furthermore, the study suggests that beyond grid extension distances of 350-530 km, off-grid solutions may be more economically viable than grid extensions. Moreover, on-grid configurations demonstrate the lowest net present cost (NPC), benefiting from the option to sell surplus electricity back to the utility grid, thereby enhancing their economic advantage over off-grid options. The strategic implications of these results are significant for global energy planning, advocating for a portfolio approach that incorporates a mix of on-grid, offgrid, and extended-grid systems, crucial for sustainably meeting future energy demands. These insights have the potential to guide research, policy, and investment decisions, promoting the cost-efficient deployment of renewable hydrogen hybrid energy systems. The outcomes of this study reinforce that a sustainable energy economy is necessary and achievable through the informed and strategic deployment of technology tailored to geographical and economic specificities.