Background

Coal will remain an indispensable major source of energy for European power generation in the coming decades (today: 30 %). There will be a considerable demand for new power plants in the EU-25 beginning in the year 2010; 200,000 MW are estimated to be replaced due to the age structure of the current power plant park until 2020, additionally 100,000 MW will be needed according to rising electricity consumption. Sustainable technologies for coal-fired power plants have to be developed to optimise environmental protection and to preserve valuable resources.

Since the mid 1990s European power generators and suppliers have studied how to improve the efficiency of conventional pulverised coal-fired power plant technology by increasing the major steam parameters and improving the water/steam cycle. Main and reheat steam parameters would be raised into the range of 700 °C and depending on inland or coastal sites net efficiencies in the range of 50 to 55 % could be achieved. Basic to all this would be new and very costly Nickel based alloys (or super alloys) for the hottest section of the cycle, new austenite for the “medium” temperature range (to keep the use of super alloys at a minimum) and finally also new ferrites. Substantial avoidance of CO2 emissions can be achieved without entailing excessive cost.

The European Commission has granted materials development programmes and investigations on the economic viability of the technology. The phased project is named the “Advanced 700 °C PF Power Plant Project” (or AD700) and Phase 1 is funded under FP 4 with 40 partners including power generators, and all major European equipment suppliers and material makers. Phase 2 of the AD700-project continued under FP 5 and contains design and test of the critical components and preparatory work for a demonstration programme. AD700 Phase 1 started in 1998 and had run for six years and AD700 Phase 2 started in 2002 and runs for five years.

The AD700 Phase 2 work has concluded to define a technology package consisting of a Component Test Facility with major critical components of the boiler and steam line systems in that a turbine inlet valve at 700 °C can be tested, and a test rig for the testing of boiler materials. As the realisation of the technology package minimises the risk for a later full-scale application, this is considered to be the last step to the future AD700-demonstration plant.