[en] Due to the intermittence and fluctuation of wind resource, the increasing penetration level of wind power will bring huge challenges to maintain the stability of power system. In order to smooth the wind power output, additional controllable power from conventional power plant or energy storage system is required. In current paper, one basic scheme of liquid carbon dioxide storage system is proposed. The parametric analysis is conducted to examine the effect of some key thermodynamic parameters on the performance of this scheme. Subsequently, the basic scheme is improved according to the results. The mathematical models of two improved schemes are developed and the performance analyses are conducted. According to the results, the optimal scheme and configuration are determined. After optimization analysis and comparison analysis, compared to the other energy storage systems, the round trip efficiency of Scheme 3 is acceptable in consideration of the energy generated per unit volume of storage. As a conclusion, the optimal scheme has a good potential for storing wind power in large scale and offers an attractive solution to the challenges of the increasing penetration level of wind power. - Highlights: • The basic scheme based on liquid carbon dioxide is presented and analyzed. • The basic scheme is improved and several improved schemes are analyzed. • The parametric analysis is conducted to determine the optimal configuration. • The parametric optimization is conducted by genetic algorithm.