Today's coal-fired power plants operate with steam temperatures of between 500 and 600 degrees Centigrade (930 to 1,100 degrees Fahrenheit) and steam pressure of 240 bars (3,500 pounds per square inch). Plants superseding the next generation will reach around 700 degrees Centigrade (1,300 degrees Fahrenheit) and about 350 bars of pressure (5,080 pounds per square inch). This will give them a significantly higher thermal efficiency, which will help protect the earth's climate and conserve the Earth's resources.

Testing has focused on the development of innovative materials and components. The carbon steel used in today's boilers and piping can only withstand temperatures of up to 600 degrees Centigrade (1,100 degrees Fahrenheit). Next-generation components (such as the evaporator, tubing, piping, and valves) will be made primarily of nickel-based superalloys, which are capable of withstanding the higher steam temperature and pressure. They replace conventional materials in the high temperature area of the steam generator, steam pipe system and turbine, and enable thermal efficiency of more than 50 percent.

 

The manufacture of high-quality components made of nickel-based superalloys presents considerable challenges, and there are only a few companies around the world able to manufacture components of the required quality.

 

Testing these components in the Scholven pilot unit will continue through 2011. The results will be evaluated and, along with the lessons learned, will be drawn on to build the new 500 MW power plant 50 plus in Wilhelmshaven.