A modified rule-based energy management scheme for optimal operation of a hybrid PV-wind-Stirling engine integrated multi-carrier energy system

In this study, rule-based energy management strategies (EMS) based on the modifications of the traditional load following (LF) and circuit charging (CC) have been proposed and developed to effectively coordinate the operation of an integrated multi-carrier hybrid energy system. The proposed EMS aim to overcome some of the challenges of the traditional rule-based EMS and broaden their application to the management of complex energy systems. The study deploys a bi-level optimisation scheme to obtain the optimal number of system components that simultaneously minimises the cost, reliability and emissions, in the outer-loop and implements the rule-based EMS in the inner-loop. Also, the results of the optimal system have been simulated for a 48 h timespan, to investigate the effects of the proposed EMS on the Stirling back-up start-ups, battery storage limits, and generation of other energy vectors. The results indicate the deployment of split back-up and batteries minimise the commitment of the back-up, dumped power and emissions. However, the number of start-ups of the back-up increases appreciably by 15.34% and 36%, with the deployment of 2-split and 4-split Stirling, respectively in CC with battery storage. Correspondingly, the operational cost of the system rises as the number of splits increases, but only a slight change in the energy cost is observed, because of the significant reductions in the capacity of the green generators. Interestingly, the batteries record many duty cycles, store less energy and attain lower discharge limits as many small capacity ST back-ups are deployed. Other results demonstrate the additional capabilities of the proposed EMS in handling complex energy systems by the substantial increase in the generation of heating and cooling with increasing splits of the back-up and inclusion of batteries in the optimal system.