This study discusses and thermodynamically analyzes several energy storage systems, namely; pumped-hydro, compressed air, hot water storage, molten salt thermal storage, hydrogen, ammonia, lithium-ion.
12 different energy storage systems are comparatively assessed thermodynamically. Exergy destruction and entropy generation rates are calculated for all systems. Energy and exergy efficiencies from source-to-electricity are calculated. The overall exergy round-trip efficiencies range from 23.1% to 71.9%.
Various application domains are considered. Energy storage is one of the hot points of research in electrical power engineering as it is essential in power systems. It can improve power system stability, shorten energy generation environmental influence, enhance system efficiency, and also raise renewable energy source penetrations.
The complexity of the review is based on the analysis of 250+ Information resources. Various types of energy storage systems are included in the review. Technical solutions are associated with process challenges, such as the integration of energy storage systems. Various application domains are considered.
Which energy storage system is most efficient?
The hydrogen storage is highest in terms of exergy efficiency corresponding to 71.9%, and the molten salt thermal storage is the least system with 23.1% efficiency. Thermal energy storage units are mostly employed to sustain the operations more smoothly for night and daytime.
How do energy storage systems compare?
A comparison between each form of energy storage systems based on capacity, lifetime, capital cost, strength, weakness, and use in renewable energy systems is presented in a tabular form.
The applications of energy storage systems have been reviewed in the last section of this paper including general applications, energy utility applications, renewable energy utilization, buildings and communities, and transportation. Finally, recent developments in energy storage systems and some associated research avenues have been discussed.