Multi-objective operational optimization of a multi-energy liquid air energy storage (LAES) in a hydrogen-based green energy hub in Singapore

With the increasing penetration of renewable energies, energy storage systems are crucial to addressing supply intermittency, reducing energy peaks and decreasing primary energy consumption and pollutant emissions. Furthermore, these systems improve the efficiency and reduce the operating costs of polygeneration plants that integrate electricity, thermal energy and cooling systems. Liquid air energy storage (LAES) has emerged as a promising technology due to its thermomechanical nature and longer lifespan compared to battery energy storage systems (BESS), as it is less affected by duty cycles. This study techno-economically analyzes the energy dispatch optimisation problem for an industrial port area (IPA) in a tropical region, using a mixed-integration linear programming approach. The performances of three different electrical energy storage technologies (i.e. BESS, hydrogen storage using alkaline electrolysers and LAES) are analysed in a capacity range of 5 MWh to 50 MWh. The results show that, at higher capacities, LAES achieves lower total costs compared to both BESS and hydrogen storage, whereas at lower capacities, LAES and BESS produce comparable economic returns. Hydrogen, while providing potential emission reductions for IPA, is not a cost-effective for electrical energy storage when using electrolysers and fuel cells integrated into the energy system. Therefore, this work highlights that LAES is a competitive and efficient energy storage option for polygeneration plants, particularly when combined with a liquid hydrogen regasification plant. The potential integration of the technology with other energy systems is further explored and discussed.