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| First parabolic trough plant using direct steam generation  Despite unusually poor radiation, on January 25, 2012, TSE 1 supplied 5 MW of electrical power to Thailand's public power network for the first time. Solarlite, based in Germany, has reached a major milestone in the development of solar thermal energy by activating this power plant in Southeast Asia. The design for direct steam generation, which was implemented commercially for the first time at TSE 1, offers the advantage of using solar radiation to heat water directly in an absorber tube, which produces the steam required to run the turbine. After developing and testing this design at three test and pilot facilities with the help of experts from the German Aerospace Centre, Solarlite is now implementing it in commercial projects.Because the technology uses water instead of the commonly used thermal oil as a heat transfer fluid, components such as heat exchangers are not needed. But most importantly, direct steam generation allows higher operating temperatures of up to 500°C, in contrast to the 395°C made possible using thermal oil. For that reason, parabolic trough plants are clearly more efficient and thus better performers in the long run. Not to mention, these power plants are especially environmentally-friendly because they do not require thermal oil, an expensive and dangerous component in limited supply. Lower CO2 emissions are another noteworthy feature: 964 t/year less than oil and 1,258 t/year less than coal. Direct steam generation requires a complex control and regulating system to control and maintain the pressure and temperature. Solarlite uses a combination of recirculation and injection technology. That way, steam is continuously reintroduced into the water cycle so that the pressure remains stable. TSE 1 has an operating temperature of 330°C with a pressure of 30 bars. "We are already working on developing this technology further. Our current project, the TSE 2 power plant, will reach an operating temperature of 400°C with 40 bars," says Joachim Krüger, CEO of Solarlite. In the joint research project known as "Duke" that is supported by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, Solarlite GmbH and the German Aerospace Centre are testing a new version of direct steam generation that will make it possible to cut energy costs even more. In collaboration with Thai Solar Energy Co. the investor and operator of TSE 1 and TSE 2, Solarlite is planning to build a total of 15 power plants with a combined output of 135 MW. Joachim Krüger explains: "Solar thermal power plants use the sun as an energy source in a very efficient way. They are definitely at least 25% more efficient than photovoltaic power plants." The efficiency of parabolic trough plants can be further increased in, for example, co-generation applications with simultaneous electricity and thermal energy usage, or when energy storage solutions are integrated. In addition, there is potential for hybrid solutions with other renewable energy sources. "This technology has a broad range of applications. The fact that energy costs can be reduced over the long term and that we can free ourselves from fluctuating prices are real opportunities for industry," adds Joachim Krüger. write your comments about the article :: © 2012 Construction News :: home page |