Integrating compressed CO2 energy storage in an oxy-coal combustion power plant with CO2 capture

To compensate for the high cost of CO2 capture, this study proposes a novel solution that integrates a compressed CO2 energy storage (CCES) system into an oxy-coal combustion power plant with CO2 capture (Oxy_CCES). The integration of energy storage has the potential to create arbitrage from variations in electricity prices. The proposed Oxy_CCES system can achieve a higher net efficiency of 34.1%, and a higher exergy efficiency of 57.5%, than that of a liquified oxygen storage-integrated oxy-coal combustion power plant (Oxy_O2). Two scenarios, i.e., retrofitting an existing oxy-coal combustion power plant (S–I) and building a new plant (S-II), were established to compare the Oxy_CCES and Oxy_O2. In S–I, the payback time of the Oxy_CCES is one year and in the S-II the levelized cost of electricity (LCOE) of the Oxy_CCES increases by 1.8%, which is lower than that of the Oxy_O2. The sensitivity analysis shows that, when the difference between the peak and the valley electricity prices and the capacities of the energy storage systems increase by 50%, the net present value (NPV) and LCOE of the Oxy_CCES system increase by 113.4% and 1.7% respectively, which are lower than the NPV and LCOE increase of the Oxy_O2. [Display omitted] •A novel integrated oxy-coal combustion power plant and compressed CO2 energy storage was proposed.•Two scenarios, retrofitting an existing plant and building a new power plant, were considered.•Compressed CO2 energy storage achieves higher exergy efficiency than liquified energy storage does.•Integration of the energy storage system increases levelized cost of electricity of the power plant.