Techno-economic analysis of using carbon capture and storage (CCS) in decarbonizing China's coal-fired power plants

Abstract

To achieve carbon neutrality by 2060, China must tackle CO2 emission from its power sector which contributes to 40% (11.8 Gt in 2019) of its total CO2 emission. Previous studies have shown that China has enough subsurface CO2 storage capacity (3,145 Gt) to store 200–300 years of CO2 emission nationwide or 600–700 years of CO2 emission from the power sector. This paper evaluates the economic benefits of using carbon capture and storage (CCS) technology to decarbonize China's coal-fired power plants and conducts a techno-economic analysis of four scenarios to achieve carbon neutrality in China's power sector by 2050. A model of levelized cost of electricity (LCOE) for coal-fired power plants equipped with CCS (CP-CCS) is used for comparing the economic competitiveness of CP-CCS with those of nuclear (NP), hydro (HP), wind (WP) and solar photovoltaic (PV) power plants. Results show that the LCOE of CP-CCS with a CO2 transportation distance of 100 km or less and coal price below 455 CNY/t (70.54 USD/t with the exchange rate set at 1 USD = 6.45 CNY) is less than those of NP, WP and solar PV especially for a high discount rate. The cost of coal and CO2 transportation are the two greatest contributors to the LCOE of CP-CCS. In addition, LCOE is sensitive to operation time of the CP-CCS. Retrofitting an existing coal-fired power plant with CCS reduces the LCOE by 10–18% compared to a newly built CP-CCS. Furthermore, a scenario of gradual increase (average annual growth rate of 0.93%) in electricity generation by CP-CCS has a lower total cost than one where coal-fired power plants are aggressively replaced by wind and solar PV power plants. This is especially true if the coal price is low and CO2 transportation distance is short. The result is savings of trillions of CNY in costs for the power sector.