A Novel Approach towards Energy Storage System Sizing Considering Battery Degradation

Energy Storage System (ESS), with its fast ramping and bi-direction power flow capabilities, is playing a more vital role in the electric market. However, it still stands on the farther end of economic viability. As a result, a good estimate of battery service life, and therefore revenue, is necessary before the investment is made in any given application. In this paper, a set of improved degradation models are propose to estimate the useful life of an ESS when subjected to daily duty cycles (4-sec resolution). The models are validated and tuned for the target Li-Nickel Cobalt Aluminum Oxide (NCA) batteries. Time to End of Life (EOL) is estimated for batteries of different sizes to provide ancillary services and/or energy services in electric market, given different end-of-cycle state of charge. Finally, the strategies which can be used to size the battery for maximizing time to EOL are discussed.