Design of a Renewable-based Remote Microgrid System in Queensland

Renewable energy-based power generation is considered worldwide to achieve net zero emission targets. The nature of renewable energy systems leads to regulation and control challenges for power system operators, especially in remote and regional grids with smaller pathways. A hybrid system such as solar, wind, biomass, energy storage, etc., could be an option to minimise this problem. Yet, constructing a hybrid system proves unfeasible in numerous remote regions where setting up renewable energy installations is hindered by limited space, geographical limitations, governmental regulations, and policy constraints. Numerous research projects have explored hydrogen as a promising, clean, and portable energy source. Despite its potential, global adoption of hydrogen from renewable sources, particularly in the power sector, has been limited due to high production costs and lower efficiency. However, recent technological advancements are driving down the cost of green hydrogen production, making it a more cost-effective alternative to traditional methods. 

There is a growing need for more studies in this field of renewable electricity generation due to the lack of research on emissions-free power generation in the Australian context of remote islanded locations. The use of hydrogen offers a solution to the challenges faced by areas with limited resources and space for renewable energy facilities. By transporting hydrogen to remote locations, it can be used to produce electricity, thereby reducing reliance on diesel generators. This approach could facilitate the integration of more renewable energy sources into electricity generation in remote regions of Australia, helping to achieve the goal of net-zero emissions. Green hydrogen would also enhance energy security by addressing the intermittent character of renewable energy sources. 

This study investigated a techno-economic assessment of designing a green hydrogen-based microgrid for a remote island in Far North Queensland. The study also aimed to determine the optimal sizing of microgrid components using green hydrogen technology. Due to the aforesaid restrictions, the green hydrogen production system and the microgrid suggested in this study are located on two separate islands. A simulation-based approach would be accomplished using HOMER Pro, a commercial software, to find the economic and technical viability of introducing hydrogen-based electricity generation on the island while producing the green hydrogen within a possible nearest location. The study also revealed cost-effective situations for green hydrogen production, transportation, and electricity generation. 

Simulation results show that the Levelised Cost of Energy using hydrogen technology can vary from AU$0.37/kWh to AU$1.08/kWh depending on the scenarios and the variation of key parameters. This offers the potential to provide lower-cost electricity to a remote community. The result of the analysis shows that the inclusion of a green hydrogen system can potentially reduce the cost of electricity production by AU$0.01 to AU$0.10 per kW depending on the approach and scenario while decarbonising the community by 50% to 100%. Moreover, adding an appropriate supply chain framework can deliver the green hydrogen required to power additional communities while maintaining a cheaper electricity supply. Furthermore, CO2 emissions could be reduced by 17,607,77 kg/year if the renewable energy system meets 100% of the electricity demand. Additionally, the sensitivity analysis in this study shows that the size of solar PV and wind used for green hydrogen production can further be reduced by 50% if existing diesel generators are considered as backup in case of weather-related uncertainties. The findings of this study would also contribute as a guideline to place hydrogen-based microgrids, not only in Australian isolated islands but also in similar global remote locations for small, clustered communities that could not support or justify large-scale renewable generation facilities but need more opportunities to install renewable generation.