Combined gas and steam power plants are the most efficient solution of fossil-fired combustion plants both for the environment and climate. The hot gases from the gas turbine are used to generate steam for a downstream steam turbine and modern plants achieve an efficiency of up to 60 percent. In addition, less CO2 is formed compared to other fossil fuels.
In December 2007, the world’s most powerful gas turbine was ignited at Irsching in Bavaria, Germany. With an output of 340 MW, the new gas turbine aims to break the world record in energy efficiency. Thanks to its improved efficiency, the gas turbine needs less fuel per generated kilowatt hour. The combination of gas and steam turbine will produce 40,000 tons less CO2 per year. In the heart of the power plant, tungsten-containing superalloy turbine blades are doing their job in the gas turbine.
The modernisation and upgrading of existing coal-fired power plants is a further big contribution to both a cleaner environment and higher energy efficiency. Such plants are among the largest producers of CO2. The efficiency of newly installed coal-fired plants is currently in the range of 47% but is likely to exceed the 50-percent mark in 2020. For such increases in energy efficiency, higher process temperatures (up to 700°C) are demanded and new materials are needed for the boiler components and piping systems. It is probable that tungsten-containing creep-resistant steels will contribute to these outstanding performances.