An evaluation method of energy storage technologies based on energetic costs

In recent decades, China and the World have been devoting a significant effort to the development of energy storage technologies. Energy storage can support electrical grids in terms of peak-shaving, frequency regulation, black start, demand side response, and help resolving challenges associated with intermittency and fluctuation of renewables. This article reviews technical and economical evaluation indicators of a variety of energy storage technologies and introduces an evaluation method by Charles J. Barnhart and Sally M. Benson with a focus on energetic costs of storage. This leads to a new metric based on the energetic cost:energy stored on Investment (ESOI). A higher ESOI indicates that more "net energy" is returned. Through studying ESOI for different energy storage technologies, we found that the ESOI of mechanical based energy storage technologies is far higher than the chemical based energy storage technologies. The commonly used lead-acid (PbA) batteries only have an ESOI of 2.