Abstract
A 100% renewable energy (RE)-based stand-alone power system can be achieved using a resilient renewable energy storage system RESS to provide a sufficient and stable power supply. This study conducted a feasibility study for a 100% renewable energy hydrogen-enabled microgrid in the Pilbara region, North of Western Australia (WA). In this feasibility study, two different sites were studied to techno-economically evaluate the transition to a 100% RE-based stand-alone microgrid (SAM) using a hybrid hydrogen-battery storage system. The first selected site was a grid-connected small-scale aboriginal community power system (150 kWh/day) to be expanded to a large-scale 100% RE SAM power system to avoid the cost of expansion of their grid connection and become a pilot zero-emission project. The second selected site was a diesel-based power system in medium-scale aboriginal communities (1.5 MWh/day). A diesel power station transition to a 100% RE SAM power system has been modelled as a pilot project using a hybrid hydrogen-battery storage system. This study demonstrated the techno-economic viability of using hybrid hydrogen-battery RESS to provide lower energy cost with sufficient autonomy and reduce the carbon footprint. Several scenarios were considered in the modelling for the most optimal option for the locality in terms of the cost of energy and GHG emissions. Both sites were modelled with the principle of a battery bank following the load fluctuations while the hydrogen fuel cell generator covers the baseload.
Simulation analyses for the grid-connected site revealed that a larger capacity of hydrogen system adds more energy autonomy at a price. An additional scenario of utilising one of the existing diesel generators for site 2 as a backup was evaluated. It is found that having the diesel generator backup is the most robust and cost-effective option. However, this option comes at the cost of having a tiny percentage (1.5%) of fossil fuel penetration, therefore incurring a 1.5% carbon footprint compared to the base case scenario.