Techno-Economic Assessment of Carbon Mitigation Options for Existing Coal-fired Power Plants in India☆

Abstract India's developmental needs in the near and long-term future will be strongly interlinked with the need to provide steady electricity to its cities and villages. The current fleet of Electricity Generating Units (EGUs) in India is mostly coal-based. These coal-fired power plants lead to a substantial amount of CO2 emissions. Due to international climate obligations, there might be a need to limit the amount of unmitigated CO2 emissions being emitted into the atmosphere. Mitigation of such emissions at coal-fired power plants offers an easily controllable way of reducing such emissions. The mechanisms to reduce emissions in coal-fired power plants may be through installation of super-critical units, repowering the plant with Integrated Gasification Combined Cycle (IGCC) or with use of coal blended with biomass. More radical emission cuts may be obtained by retrofitting the existing plants with CO2 Capture and Storage (CCS), a technology with the ability to reduce the emissions by 80-85% of the current emissions levels. This paper begins with a brief insight into some of the mechanisms to cause emission reductions in coal-fired power plants. It focuses mainly of how retrofitting the power plants with CCS technology will affect the techno-economic of the plant. Three types of plants will be analyzed, viz, Low performance, medium performance and high performance; the categorization being based on the current Indian fleet of EGUs. We analyze five pathways for mitigation, with two focusing on efficiency improvements and three on CCS technology. The results show that overall cost of avoidance for CCS ranges from US$ 59.54 to US$ 85.41 per tonne of CO2. There is a strong incentive for repowering of old plants to supercritical units and their subsequent retrofitting with CO2 capture systems than direct retrofitting of low performance plants.