A model-based parametric and optimal sizing of a battery/hydrogen storage of a real hybrid microgrid supplying a residential load: Towards island operation

In this study the optimal sizing of a hybrid battery/hydrogen Energy Storage System “ESS ”is assessed via a model-based parametric analysis in the context of a real hybrid renewable microgrid located in Huelva, Spain, supplying a realtime monitored residential load (3.5 kW; 5.6 MWh/year) in island mode. Four storage configurations (battery-only, H 2 -only, hybrid battery priority and hybrid H 2 priority) are assessed under different Energy Management Strategies, analysing system performance parameters such as Loss of Load “LL ”(kWh;%), Over Production “OP ”(kWh;%), round-trip storage efficiency ESS (%) and total storage cost ( €) depending on the ESS sizing characteristics. A parallel approach to the storage optimal sizing via both multi-dimensional sensitivity analysis and PSO is carried out, in order to address both sub-optimal and optimal regions, respectively. Results show that a hybridised ESS capacity is beneficial from an energy security and efficiency point of view but can represent a substantial additional total cost (between 100 and 300 k €) to the hybrid energy system, especially for the H 2 ESS which presents higher costs. Reaching 100% supply from renewables is challenging and introducing a LL threshold induces a substantial relaxation of the sizing and cost requirements. Increase in battery capacity is more beneficial for the LL abatement while increasing H 2 capacity is more useful to absorb large quantities of excess energy. The optimal design via PSO technique is complemented to the parametric study.