Power production and emergy-based sustainability in port areas

Port activities represent an outstanding sector in Blue Economy, with a contribution of approximately 11% to the Gross Value Added of the Blue Economy in the European Union. In addition, Blue Economy guidelines for Trans-European Transport Network — TEN-T — consider the deployment of structures and facilities enforcing clean On-Shore Power Supply — OPS — for ships at berth, and sustainable marine transport and port activities. This paper presents a comprehensive emergy-based sustainability assessment on the improvement of port areas with power supply systems based on Oscillating Water Column technology — OWC — to be used as specific OPS facilities, grid supply or ultimate storage systems. Emergy evaluation accounts for materials, machinery and workers, as well as their direct and indirect CO 2 emissions and embodied energy — eMergy —. Emergy-based indexes are calculated to appropriately quantify the degree of sustainability and renewability of a marine project, its dependence on social investments and the pressure on local ecosystems. A case study of OWC power facility commissioning in a port terminal project is presented for a better focusing. Without loss of generality, results show that the implementation of OWC power facility into the port system improves the overall sustainability, renewability, emergy-based indicators, as well as a reduction in CO 2 emissions, even if breakwater construction and port activities are not sustainable solely, involving non-renewable resources and fluxes from the environment and society. Moreover, the emergy budget allows to analyse the evolution of sustainability during the operational phase due to delays in construction and operational stops, showing that emergy accounting is a valuable tool for long-term management and planning of port infrastructure regarding sustainability.