Within the scope of the demonstration project „Kraftwerk 50plus“, E.ON Kraftwerke is developing the 700°C power station yielding 50 percent efficiency. The objective is to reduce the required fuels and thus the CO₂ emissions by up to 33 percent. The first 500 MW demo plant is to go on line in Wilhelmshaven in 2014.

For a high efficiency to be achieved, the steam parameters – i.e. pressure and temperature – must be clearly increased. However, the classic materials of conventional power station construction are overtaxed in ranges where highest stresses (700°C, 350 bar) are ruling.

Thus, the safe operation of a “Kraftwerk 50plus“ demands extensive materials research beforehand: instead of ferrous materials, E.ON Kraftwerke is analysing new nickel-based materials to be used for the critical components. Due to their alloy composition and resulting structures, these exhibit a clearly higher strength – even at higher temperatures.

A special challenge is the development of the 700°C/720°C steam turbine using nickel-based alloys. In particular the long-term behaviour as well as the welding and mechanical processing of materials need to be explored. E.ON Kraftwerke is implementing this project together with the manufacturers.