In this study, the economic feasibility of an Energy Storage System (ESS) was conducted to examine the effects of a tariff system for the promotion of ESS. The results are summarized as follows. First, if it were not for the tariff system for ESS, none of the contract types could secure the economic feasibility of ESS, Second, in terms of the B/C ratio, the base tariff discount was 18 times more effective than the ESS charging rate discount. Third, in the case of the Industrial (KAPII), Commercial (UL) and Educational (UL) contract types, which are available only for the charging rate discount, the economic feasibility was not secured. Fourth, in the case of Industrial (UL) and Commercial (UL) contract types, which are available for both the base tariff and charging rate discount, the economic feasibility was secured. Based on economic feasibility analysis, the combinations of the required discount on either the charging rate, base tariff, or on both for NPV = 0 were also analyzed. With this result, a modification of the current tariff system for the promotion of ESS was suggested.
