Page 1 May 08 Energy – Fossil Power Generation 700°C Steam Turbine for highest efficiency Energy – Fossil Power Generation 700°C Steam Turbine – Challenges  Coal fired steam power plants are still main contributors to fossil power production  Additional power demand and replacement of aging power plants require new installations  Fuel prices, CO 2 tax and carbon capture negatively impact cost of electricity and power plant efficiencies  Customers demand high cycle efficiencies to compensate for these effects Source Siemens PG GS Worldwide electricity generation Other Renewables PWh % p.a. Fossil Fuels 64% 6% 16% 15% 21% 40% Natural Gas 22% Hydro 15% Nuclear 13% Oil 3% Coal 39% 2% 8%

Page 2 May 08 Energy – Fossil Power Generation 700°C Steam Turbine for highest efficiency Energy – Fossil Power Generation 700°C Steam Turbine – Innovative Step  Increase steam power plant efficiencies by rising main steam parameters  Increase temperature (+100°C)  Increase pressure (+100 bar)  For maximized gain raise pressure and temperature at the same time Temperature Pressure Gas Turbines 25 bar / 1400°C 700°C Steam Turbine 350 bar / 700°C Conventional Steam Turbines 250 bar / 600°C  increase To raise plant efficiency  raise Carnot efficiency To raise Carnot efficiency  raise temperature! Carnot Efficiency

Page 3 May 08 Energy – Fossil Power Generation 700°C Steam Turbine for highest efficiency Energy – Fossil Power Generation 700°C Steam Turbine – Implementation  Increased material strength at higher temperatures needed: conflicting demands  Measure: use of Nickel alloys in major turbine components  First application of expensive Nickel alloys for thick-walled and heavy parts > 10 tons  New technologies, cooling and design concepts, production processes Nickel Alloy Forging Nickel Alloy Casting

Page 4 May 08 Energy – Fossil Power Generation 700°C Steam Turbine for highest efficiency Energy – Fossil Power Generation 700°C Steam Turbine – Innovation Major Research Work on  Thermal Turbine Design  Mechanics, especially long term behaviour  Materials (alloy properties)  Manufacturing (casting and machining) Yields  Technological leap in steam turbine design  Entire new generation of steam turbines cold hot

Page 5 May 08 Energy – Fossil Power Generation 700°C Steam Turbine for highest efficiency Energy – Fossil Power Generation 700°C Steam Turbine – Customer Value Increased customer value due to  Increased power plant efficiency  Approximately 7% less fuel consumption and CO 2 emission  Means to compensate for efficiency deficit due to carbon capture  No cut backs on reliability and operational flexibility Goal: > 50% net efficiency State of the art: 46% net efficiency approx. 7% less fuel and CO 2

Page 6 May 08 Energy – Fossil Power Generation 700°C Steam Turbine for highest efficiency  Siemens currently in leading position for 700°C steam turbine technology  Target: Development of 700°C full-scale pilot plant together with e.on by 2014  Of special interest with increasing emission tax  Planned scale-up to large plant size >800MW when operation experience is available  Potential to replace a part of current high-end steam power plant market  Market entry expected after 2015 Market success Energy – Fossil Power Generation 700°C Steam Turbine – Market success Market potential only ST > 115 MW (F-Market) GW Market potential for 700°C ST STPP Super Critical STPP Sub Critical ST in CCPP ST in NPP Source PMD2

Page 7 May 08 Energy – Fossil Power Generation 700°C Steam Turbine for highest efficiency Energy – Fossil Power Generation 700°C Steam Turbine – Innovation Process  Based on long term development  Participation in European research programs  Utilization of common “Mülheim inventor days” with gas turbine, generator and steam turbine engineering  Conduct internal concept workshops  Simultaneous multi-field research in engineering, materials and manufacturing Source E.ON

Page 8 May 08 Energy – Fossil Power Generation 700°C Steam Turbine for highest efficiency Energy – Fossil Power Generation 700°C Steam Turbine – Lessons learnt Improvements in  performance,  costs and  operational flexibility of conventional turbines Customer Benefit 1) Evolutionary approach Technology demonstrator approach Technology download 700°C ST 600°C ST 1) Net Present Value, Performance, Flexibility, … Time Technology Downloads Contact: Dr. Ernst-Wilhelm Pfitzinger,