Life Cycle Optimization of Renewable Energy Systems Configuration with Hybrid Battery/Hydrogen Storage: A Comparative Study

With the booming development of renewable energy systems, energy storage technology is undoubtedly becoming an underlying role and serving as the enabling technology for the long-term reliability of the intermittent renewable energy systems containing photovoltaic and wind power generation. Electrical storage via Li-ion battery and hydrogen storage via electrolyser and fuel cell are two promising candidates providing a fast response in load leveling. However, the researches on the costs and benefits of each method are very limited, especially from a life-cycle perspective. To this end, this paper firstly builds an economic model containing the investment and operational cost of each component. For comprehensiveness, both electricity production and heat recovery are considered in the economic model. Subsequently, a life-cycle capital optimization problem is formulated to determine the optimal configuration of a hybrid renewable energy system, with constraints on balancing the given load profile. In order to make the resulting global mixed-integer linear programming (MILP) problem tractable, a pair of binary integer variables are introduced to describe the power flow direction from or into the energy storage systems. Finally, the optimized results of both energy storage methods are quantitatively compared to analyze the costs and advantages. Furthermore, the potential of the hydrogen energy storage is discussed based on the prediction of cost reduction in the future hydrogen industry. The analysis in this paper provides instructive guidance for the economic configuration of hybrid energy systems in the present and in the future.