ABC of Carbon Weekly Blog - I is for International Energy Agency (IEA)

Many coal-fired power stations all over the world currently operate at efficiencies well below 30%. 'This is a significant waste of energy and an unnecessary cause of climate-damaging CO2 emissions. Given that the share of coal in power generation is rising, this is alarming', Nobuo Tanaka, Executive Director of the International Energy Agency (IEA), said in Paris on 23 October 2007. 'Since coal-fired power generation technologies with efficiencies close to 45% are already operating in certain locations, we must make increasing the efficiency of new fossil-fuelled power plants a priority, above all in major coal-using countries.' The new IEA publication Fossil fuel-fired power generation - case studies of recently constructed coal and gas fired power plants highlights these challenges. In a series of case studies, the IEA assessed which are the most cost effective, and which have the highest efficiencies and lowest emissions. The report shows that technologies with high efficiency and very low conventional pollutant emissions are available now at acceptable cost for a wide variety of fuel types. Depending on the quality of coal and geographical location, modern coal-fired technologies exist that operate from about 35% to close to 45% efficiency. Efficiencies approaching 50% (higher heating value basis) are envisaged within the next 10-15 years, as development of very high temperature steam conditions are conditioned. Natural gas-fired combined cycle units are more efficient at over 50% now, less expensive and quicker to build than coal-based systems. Advanced developments in natural-gas-fired turbines will increase efficiencies of these systems even more, maintaining their strong presence for new power projects. Developments in gas turbines will also benefit commercial offerings for coal-based Integrated Gasification Combined Cycle (IGCC) plants, with efficiency approaching 50%. 'The challenge to the policy makers now is to formulate measures that would enable wider deployment of these technologies globally, but particularly in countries where demand is growing at the highest rates, while also promoting technological development towards even higher efficiency', said Mr Tanaka.