Which energy storage system airflow is simpler

Further analysis of dynamic conditions should be done, with the aim of identifying any potential design implications. Liquid Air Energy Storage (LAES) systems are thermal energy storage systems which take electrical and thermal energy as inputs, create a thermal energy reservoir, and regenerate electrical and thermal energy output on demand.

The liquid air storage section and the liquid air release section showed an exergy efficiency of 94.2% and 61.1%, respectively. In the system proposed, part of the cold energy released from the LNG was still wasted to the environment.

Energy storage technologies can be classified into four main categories – mechanical energy storage (e.g. compressed air energy storage, pumped hydro energy storage), electrical energy storage (e.g. capacitors), thermal energy storage (e.g. liquid air energy storage), and chemical energy storage (e.g. lithium batteries, fuel cells).

The first concept, available in the literature on using liquid air as the storage medium, was proposed in 1977 by Smith . The core component of the system proposed was a regenerator used both to cool down and to heat up the air during the liquefaction process and the discharge phase, respectively.

The storage of energy in liquid form (rather than as a high-pressure gas as in CAES systems) results in a higher energy density for liquid air systems, which translates to significantly lower storage volumes (in the order of 700x) and thus higher flexibility.

A low-pressure cold thermal energy storage was integrated into the LAES to recover the cold thermal energy wasted from the regasification of the liquid air during the discharge phase. The cold energy stored was then used to assist the liquefaction process during the charge in order to increase the round-trip efficiency.