Energy demand of liquefaction and regasification of natural gas and the potential of LNG for operative thermal energy storage

The world trade volume of Liquefied Natural Gas (LNG) is increasing year by year. Unlike gaseous natural gas (NG), which is transported through a fixed network of pipelines, LNG offers more flexibility to both the exporters and the importers as it can be transported between any pair of exporting and receiving LNG terminals. The LNG process, consisting of liquefaction, transportation, storage, and regasification of LNG, is accompanied by certain energy demands. The paper focuses on the evaluation of the chain of energy transformations involved in the LNG process. Based on the review of existing information, the entire process is evaluated from the view of the potential use of LNG for direct storage of cold and indirect storage of power. The analysis of the existing data shows that the overall efficiency of using LNG for operative energy storage depends very much on the technologies involved and on the overall capacity of the particular technology. The combination of energy-efficient liquefaction technologies and regasification technologies with energy recovery makes it possible to employ LNG as an energy storage medium even when transported over large distances.