Techno-economic and environmental assessment of hydrate-based cold storage for building air-conditioning

As global demand for low-carbon buildings grows, hydrate-based cold storage has emerged as an efficient solution for energy management in building cooling. However, the lack of large-scale experimental validation under real-world operating conditions remains a critical barrier to its practical deployment. To address this gap, this study systematically evaluates the techno-economic and environmental performance of a hydrate-based cold storage system through a real-world demonstration project. A critical methodological innovation is the integration of an internal circulation gas disturbance unit, which effectively overcomes the long-standing challenges of hydrate formation and stability, thereby enabling enhanced system performance and peak-load shifting capability. The system achieved a peak-load shifting ratio of 59.62%, outperforming ice-based storage (36.00%), and reduced annual electricity consumption by 76,812.78 kWh. Economically, it delivered a low unit cooling cost of 0.28 CNY/(kWh·m2), a post-tax static payback period of 2.98 years, an internal rate of return(IRR) of 51.35%, and a post-tax net present value(NPV) of 2.58 million CNY. These results demonstrate favorable economic feasibility and provide a robust benchmark template for evaluating future cold energy storage systems. In addition, annual carbon emissions were reduced by 14.79% and 18.65% compared with conventional air-conditioning and ice storage systems, respectively. Overall, this study provides rare large-scale empirical evidence under real operating conditions, highlighting the significant potential of hydrate-based cold storage for improving energy efficiency and supporting low-carbon building and district cooling applications.