Port Energy Supply Through An LNG-Powered Integrated Grid

Abstract

Ports are primary importance infrastructures when considering the transportation of people and goods across the planet. Two of the biggest issues linked to harbor areas are the pollutant emissions from moored ships, as well as the huge energy demand coming from ships and other activities that take place inside of the port boundaries. To tackle these challenges, the effort on the ship-side is to promote the transition to Liquefied Natural Gas (LNG) propulsion, while on the harbor-side is to implement electrical ship feeding. In general, using LNG for bunkering purposes implies its storage onshore using dedicated tanks. The regasification of LNG in situ can be exploited to cool down a water-brine flow (i.e. ethyl-alcohol and water). The cold brine can be used to increase the efficiency of a standard inverse cycle to produce cold (i.e. -30°C) used for refrigeration purposes inside ports. Then, the NG flow can be used to produce electrical energy with a standard turbogas cycle with energy recovery from flue gases. The generated electricity directly runs the standard inverse cycle with ethyl-alcohol and water brine to completely fulfill the energy demand for cold thermal power. The electricity still available is then used to supply the onboard systems of moored ships, or otherwise is sold to the users operating in the port. The flue gas coming from the turbogas plant can be used to provide both heating and process heat, through a dedicated heat exchanger and a natural gas boiler. The new envisaged plant can exploit all possible useful effects coming from the regasification process, helping to push towards a greener energy management system in harbor areas, through smart operative integration of the several available energy systems and the implementation of efficient energy smart grids.