Optimum design of solar photovoltaic based hydrogen energy system for macro and micro distribution

Abstract

With the growing concerns on energy security and climate change, it is crucial to develop a more sustainable energy system before fossil fuel reserves are depleted or global warming impacts the environment more critically. Hydrogen has been regarded as the fuel of the future as it possesses numerous benefits as an energy carrier. Producing hydrogen using renewable energy through electrolysis process allows the yield of low-carbon hydrogen with minimum carbon footprint. Malaysia receives abundant sunshine throughout the year and hence the feasibility of solar-based electrolytic hydrogen generation is worth investigation. Considering the potential uses of hydrogen as transportation fuel, energy storage, and secondary electricity supply, this study aimed to develop a holistic framework for the optimization of a solar photovoltaic based, integrated hydrogen-electricity supply system based on micro and macro level plannings. Micro-planning of hydrogen energy system allows it to be designed in greater details but the allocation of resources within networks is usually not considered. The following models have been proposed in this thesis for microlevel planning of hydrogen energy system: i) mathematical model to optimize solar panel orientation for maximum solar radiation yield, ii) mathematical model to optimize a single-site hydrogen-electricity supply system based on the average day energy profile, and iii) mathematical model to optimize a single-site hydrogenelectricity supply system based on annual hourly energy profiles to consider the intermittency of renewables. Meanwhile, macro-level optimization of hydrogenelectricity supply system provides a bigger picture by designing the optimal hydrogenelectricity supply chain at regional, state or country level. In such cases, geographical conditions should be taken into account when determining the optimal locations and capacities of supply chain infrastructures. The final model proposed in this work represents a spatial optimization framework for multi-site hydrogen-electricity supply chain. Spatial optimization integrates spatial considerations into optimization model which provides powerful tools for location-allocation modelling, land-use planning, and urban design. This allows the determination of optimal supply chain configuration and transportation of products from one site to another. For this study, MATLAB and GAMS have been used for mathematical optimization, while ArcGIS was adopted for spatial analysis. Case study results indicated that the installation of solar tracking system could improve the solar radiation yield up to 22.41% and reduce the cost of microgrid by 7.2%. Furthermore, 32 to 55% of cost reduction was observed when only 95% of the loads were targeted in microgrid. Moreover, the total investment cost of an integrated hydrogen-electricity supply network in Johor was found to be 13.5 billion USD/y. Overall, a systematic framework for the optimization of hydrogen energy system had been developed and demonstrated in this study. For future work, more variety of energy sources should be considered for hydrogen production and the scope of study should be extended to whole Malaysia for a full picture of hydrogen energy system in this country.