Quantifying the integrated contribution of short-term energy storage under increasing energy decarbonisation and meteorological uncertainty

Short-term energy storage (STES) plays an indispensable role in supplying flexibility services within a decarbonizing power system. The complexity of quantifying STES's contributions in the diverse external environments has presented a barrier to its subsequent development. Based on a carbon-cost internalised grid simulation model and a marginal value decomposition framework, this study quantifies and decomposes the marginal contributions of STES in renewable-dominated power systems and analyses their underlying driving factors. The results indicate that carbon compliance costs constitute the primary source (38.8%) of STES's marginal value (62.5 €/MWh), while single-function constraints may lead to a 35%–47% value reduction. The marginal value of STES exhibits a nonlinear response under varying carbon prices and renewable energy penetration rates. Moreover, meteorological uncertainties exhibit both asymmetric and nonlinear effects on STES's marginal value across different renewable penetration rates. The proposed model provides a universal analytical instrument for assessing STES's contributions and thereby informing the design of effective incentive mechanisms.