Power Generation
Challenges in the areas of energy and the environment can be met not by doing without technology but rather by continuing to develop it to save energy and protect the environment in other words by developing more efficient technologies.
Improving the efficiency of energy systems will therefore play a major role in solving the energy and environmental problems of the future. To improve efficiency, there must be a rapid transfer of technology from the industrialized countries to developing countries. That will mean using ultramodern technologies when building power supply systems in developing and newly industrializing countries. Thereby using fuels more efficiently so that less damage is done to the climate and resources are not used up.
Siemens is the world's only supplier, along with its partners, that offers the complete spectrum of modern power plant technology: ranging from conventional thermal power plants to advanced technologies like Integrated Gasification Combined Cycle, and from wind power systems and hydro power to fuel cells for centralized and decentralized electricity generation. We also offer a broad range of products, solutions, and services for the industrial applications of customers in the petroleum and natural gas industries and in other industry sectors. Our digital instrumentation & control systems with state-of-the-art hardware and software standards increase the economic efficiency and environmental compatibility of power plants and industrial installations.
Coal-fired power plants  more
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The most important indicator for the energy efficiency of a power plant is its electrical efficiency. Higher efficiency means lower fuel consumption and fewer pollutant emissions.
For coal-fired power plants, further improvements in efficiency primarily depend on two variables: increasing the two steam parameters, pressure and temperature, and reducing losses in the steam water cycle. Efficiency should exceed the 53-percent mark by 2020. Coal consumption per kilowatt hour will then be only 230 grams, with CO2 emissions of 620 grams.
The Huaneng Yuhuan 4x1000 MW Ultra-supercritical Coal-fired Power Plant sets a new milestone in construction of highly efficient clean coal-fired plants in China. Shanghai Electric, the Siemens JV partner, supplied 4 sets of steam turbines and generators to the plant, applying Siemens technology. By using the most advanced Siemens ultra-supercritical technology, the plant is top-ranking in terms of unit capability, environmental protection, high efficiency and resource saving. Its overall efficiency reaches 45%.
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Combined-cycle power plants more
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The best combined-cycle power plants had achieved an efficiency of 52 percent by 1992. The Mainz-Wiesbaden plant in Germany reached an efficiency of over 58 percent in 2002, the world record for that year. CO2 emissions per kilowatt hour are only about 340 grams, thanks to high efficiency and the use of natural gas, a low-carbon fuel. That means that combined-cycle power plants are the conventional power plants that offer the most protection to the environment and the climate.
To further increase the efficiency of gas-fired combined-cycle power plants, the steam/water cycle must be optimized and the gas combustion temperature must be further increased. That will require new materials with new crystalline structures. In addition, an improved coating must be used to protect the materials against corrosion and high temperatures. Combined-cycle power plants fueled with natural gas could therefore have an efficiency ratio of more than 60 percent by 2020.
The Huaneng Shanghai combined cycle power plant is one of the biggest plants of its kind in China. Featuring three combined-cycle units equipped with three advanced gas turbines from Siemens, the plant has a total output of 1,200 MW and a net efficiency rating of 58 percent. Named Best Gas Power Plant in Asia in 2007, this single-shaft plant exhibits tremendous advantages in providing electricity at low cost and low emission for the Shanghai area.
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Integrated Gasification Combined Cycle (IGCC) power plants more
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Due to the particular advantages of the combined-cycle process, this technology will be used in future not only for natural gas, but also for fuels such as coal, which is abundantly available, biomass, or residues from refineries. The greatest success is promised by combined-cycle power plants with integrated gasification systems. In Europe this concept has already been implemented in Buggenum, Netherlands, using coal, and in Puertollano, Spain, using a mixed fuel made of coal and oil coke from a refinery. In a first step the fuel is gasified. Then the generated syngas, mainly a mixture of carbon monoxide (CO) and hydrogen (H2), is purified and used in a gas turbine with a downstream unfired heat recovery steam generator, in other words the combined-cycle process is used. Today's gas turbine technology in combination with integrated coal gasification cycle can achieve efficiencies of over 47 percent.
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