Planning multi-duration energy storage for power system resilience enhancement under extreme cold weather

• A multi-layer generation-network-load impact model for extreme cold weather is developed. • A cost-resilience balanced multi-duration energy storage planning model is formulated. • An energy storage siting and sizing case study is conducted on the actual power grid in Xinjiang. • The economic feasibility of installing ES insulation and oversizing ES capacity is compared. • Scenario sensitivities on regional VOLL, load priority, and cold wave duration are assessed. Frequent extreme cold events have recently exposed the vulnerability of high-renewable power systems: generation output declines, icing reduces transmission capacity, and heating demand surges simultaneously, leading to severe reliability risks. Therefore, power systems with high renewable penetration must plan multi-duration energy storage to enhance system resilience. In this study, a comprehensive energy storage planning framework is presented to retain the system resilience under extreme low-temperature conditions considering the coupled interactions among generation, network, and load. First, the impacts of extreme cold, reduced generation output, transmission line failures due to icing, and surges in load demand are modelled. An integrated optimization model is then formulated to minimize total system cost by optimally allocating battery energy storage and seasonal hydrogen energy storage, subject to operational constraints and reliability targets, especially taking the differential value of lost load into account. Application to the Xinjiang power grid demonstrates that strategic deployment of multi-timescale energy storage reduces the expected energy not supplied from 3.23% to 0.09% and lowers total system cost from 35.22 to 27.57 billion yuan, effectively balancing cost and reliability. Sensitivity analysis further indicates that the optimal storage configuration is highly sensitive to regional value of lost load, cold-weather impacts on energy storage efficiency, load-priority schemes, and the duration of extreme cold events.