Abstract
Kazakhstan’s power system is undergoing a structural transition from coal dominant generation toward higher shares of variable renewable energy (VRE). While policy targets signal a steady growth of wind and solar, their variability raises concerns about adequacy, reliability, and the ability of a historically centralized grid to accommodate new patterns of supply. This paper presents a scenario based assessment of energy storage systems (ESS) as a flexibility resource for Kazakhstan, using an open, replicable modeling workflow in PyPSA. We construct a geographically structured, hourly resolved network representation calibrated to present day conditions and then explore three counterfactuals: a 2020 baseline with negligible ESS; a 2030 case in which VRE reaches $30 \%$ of annual generation but storage is absent; and a 2030 case that retains high VRE while introducing distributed batteries at key nodes. Across winter and summer representative periods, we measure curtailment, line loading, solar utilization, and the direct contribution of storage to demand coverage. Results indicate that ESS reduces renewable curtailment by roughly $5-6$ GWh in the modeled days, lifts solar utilization by $5-9 \%$, and covers up to $10 \%$ of total demand at winter peaks. Network loading remains tight in summer, suggesting that storage alone cannot resolve structural congestion. The findings support ESS as a necessary-though not sufficient-enabler of Kazakhstan’s low carbon transition, and they motivate integrated planning of storage, transmission expansion, and demand side measures.