Energy resilience enhancement against grid outages for a zero-emission hotel building via optimal energy management of onshore and offshore energy storages

Increasing integration of renewable energy into building systems necessitates enhanced flexibility and resilience to maintain stability under dynamic grid conditions and unexpected outages. Existing research inadequately addresses energy flexibility for demand response and resilience during outages, underutilises hybrid mobile/stationary electrical/mechanical energy storage, and overlooks ocean-based renewable energy potential. To bridge these gaps, this study develops an advanced energy management system leveraging building batteries, electric vehicles, and wave energy converter reservoirs to improve flexibility and resilience in a net-zero energy building. Scenario-based analyses demonstrate that coordinated activation of sources outperforms single-source strategies. Coordinated control increased the flexibility index to 192.67% (1.93 times incentives), reducing costs to 80.66%; prioritisation further boosted flexibility to 199.89% and lowered costs to 79.52%. Resilience was enhanced by integrated wave energy converters, which enabled strategic energy storage/release, elevating from approximately 83% to over 99%, nearly eliminating CO₂ emissions and diesel backup reliance. Coordinating flexibility sources mitigates power shortages and reduces energy lag, strengthening system flexibility and outage resilience. The study's originality lies in pioneering hybrid storage integration for dual flexibility-resilience objectives, novel utilisation of wave energy converters as demand-responsive assets, and efficient control strategies addressing profit maximisation and outage recovery. This research provides practical implications for reducing fossil fuel reliance and ensuring stable operations during grid disturbances, particularly applicable to coastal urban areas with ocean energy potential and electric vehicle adoption, offering a replicable model for net-zero transitions. This work bridges critical gaps in flexibility source coordination and ocean energy utilisation, advancing resilient, grid-interactive smart buildings.