Techno-economic boundaries of hydrate-based cooling thermal energy storage

Driven by carbon-neutrality targets and the growing need for peak–valley regulation in power systems, building cooling increasingly demands cool thermal energy storage (CTES) solutions that remain techno-economically viable across regions. This study develops a unified, annual-scale simulation framework (fixed building and system topology) to evaluate a hydrate-based CTES system across Shenyang, Beijing, Guiyang, Shanghai, and Guangzhou in China. Two operating boundaries are compared—single cooling and combination cooling—with CRS and an ice CTES system as benchmarks. A full-factorial scan over cold charge temperature, conversion ratio, and latent heat is conducted to quantify annual energy consumption, COP, cooling-time structure, operating cost, payback period, NPV, and LCOS. Variance-based factor attribution (ANOVA–η 2 ) is used to identify dominant drivers, and a bi-objective energy consumption–payback Pareto front is constructed to map the feasible design set. Results show that hydrate CTES maintains robust energy competitiveness in both modes, governed by the coupled effects of charging-stage efficiency, peak-period displacement, and charging/discharging time-window constraints. As conversion ratio and latent heat increase, the system shifts from a capacity-limited regime to a time−/structure-limited regime, more prominently under combination cooling. Economic performance exhibits strong regional stratification: payback reaches ∼2 years in Shanghai and Guangzhou but typically remains ∼5–9 years in Shenyang, Beijing, and Guiyang, highlighting clear region-specific applicability boundaries shaped by tariff structure and shiftable electricity. The proposed attribution–Pareto workflow delivers actionable parameter windows for regional deployment and investment decision-making.