多模式太阳能辅助液态二氧化碳储能系统的运行策略与经济性分析

Abstract As a novel approach to energy storage, the liquid carbon dioxide energy storage (LCES) system is gaining increasing interest for its potential to deliver high energy density while offering greater flexibility in site selection compared to traditional methods. However, its energy release capability during the expansion process is limited by the availability of compression heat, leaving considerable room for optimization. This study proposes a solar-assisted LCES system to address the limitations of traditional systems related to compression heat recovery. Thermodynamic evaluation indicates that incorporating solar energy notably improves the system’s thermal efficiency. This study examines the system’s operational behavior across an entire year under solar-assisted conditions. Results show that the system achieves its highest power generation performance in spring, with electricity output reaching up to 158,023 kWh. Throughout the year, the system primarily operates in Mode 1, with Mode 2 employed under low solar irradiance conditions and Mode 3 used to harness excess solar energy for power generation. Economic analysis indicates that due to the addition of solar mirror fields and related equipment, the integrated system incurs a significantly higher investment cost of $468,911, compared to $51,939 for the conventional system. Its levelized cost of electricity (LCOE) is also higher, at 0.113 $/kWh versus 0.059 $/kWh. However, the solar-assisted system offers a notably shorter payback period of 10.78 years, in contrast to 19.05 years for the traditional system. In addition, the influence of the solar mirror field size on the system’s cost-effectiveness was examined through sensitivity analysis, underscoring the critical role of proper system design in enhancing economic benefits.