Potential for Economic Greenhouse Gas Reduction in Coal-fired Power Generation
AUTHOR: Irene Smith
DATE: September 2001
The age distribution of power stations in various regions is compiled to give some idea of the installed capacity which might be economically replaced or upgraded in each area. Analysis of potential greenhouse gas reduction in coal-fired power stations requires detailed knowledge of coal composition and energy flows to obtain accurate efficiency data for plant under representative operating conditions. This results in CO2 equivalent emission factors per engy output but surogate data from heat rates, boiler efficiency and fuel use also indicate greenhouse gas emissions reduction. Studies yielding such data are reviewed for the options of upgrading coal or using it with other energy sources, plant upgrading and optimisation, repowering and cogeneration or combined heat and power (CHP).
A substantial proportion of the total of 500 GWe installed capacity of plant over 20 years old would benefit by deploying more co-utilisation of coal with natural gas and biomass, plant upgrading and optimisation along with CHP in most regions. In particular, much could be gained by improving the coal quality and power generating efficiency in those countries where these are great deal less than the OECD average and where more coal will e used in future. In OECD countries, current FBC repowering technology probably offers no greenhouse gas reduction while supercritical PC, IGCC and gas turbine repowering have good prospects. Their relative economic merits need to be decided for each case but it appears prudent to maintain fuel flexibility in reducing greenhouse gas emissions.