Solar power towers

The Cu-CI thermochemical cycle has been under development for several years. The goal is to achieve a commercially viable method for producing hydrogen at a moderate temperature ( 550°C). This chemical process, if successfully developed, could be coupled with several types of heat sources, e.g. the supercritical water reactor, the Na-cooled fast reactor or a solar heat source such as the solar power tower with molten salt heat storage. The use of lower temperature processes is expected to place less demand on materials of constmction compared to higher ( 850°C) temperature processes. 

H2A analysis was used to predict hydrogen production costs as shown in Table 2. These results are based on the use of solar power tower as the heat source and also include assumptions that have yet to be validated. Work is ongoing in these areas. Nevertheless, the preliminary hydrogen production costs as well as the preliminary efficiency numbers indicate that the Cu-CI cycle has promise and that further R D is justifiable. 

Storability is another important attribute of the chemical fuel hydrogen. Hydrogen makes it possible to economically store over time—for the winter season, for example—energy derived from intermittent sources such as solar power. Hydrocarbons (natural gas, petroleum, coal) obviously are easy to store. But how do you store sunlight or the heat from a nuclear reactor Storage works very well in solar power tower plants, where heat is stored very efficiently in 24-hour, day-and-night cycles in molten salt storage tanks.2... 

Solar Two - Solar Two is a retrofit of the Solar One project (see above). It is demonstrating the technical feasibility and power potential of a solar power tower using advanced molten-salt... 

Parabolic troughs Solar power tower Dish/engine... 

Concerning solar-powered processes, two-step cycles are also under investigation, which require higher temperatures like the Zn/ZnO cycle or ferrite cycles. Most recently a closed ferrite cycle was demonstrated in the HYDROSOL-2 project in a 100 kW range on a solar test tower in Almeria (Roeb, 2008). 

Reilly H. E. and G. J. Kolb (2001). An Evaluation of Molten-Salt Power Towers Including the Results of the Solar Two Project. Sandia National Laboratories. 

Sargent and Lundy LLC (2003). Assessment of Parabolic Trough and Power Tower Solar Technology Cost and Performance Forecasts. National Renewable Energy Laboratory (NREL). 

Solar One - A solar thermal electric central reciever power plant ("power tower") located in Barstow, California, and completed in 1981. The Solar One had a design capacity of 10,000 peak kilowatts, and was composed of a receiver located on the top of a tower surrounded by a field of reflectors. The concentrated sunlight created steam to drive a steam turbine and electric generator located on the ground. 

Solar-Hybrid Gas Turbine-Based Power Tower Systan (REFOS),... 

Antal, M.J. 1978. Tower power producing fuels from solar energy, in Toward a solar civilization, R.H. Williams (Ed.) MIT Press, Cambridge, MA,... 

The Solar II power plant near Barstow, California. The central tower is more than 70 meters tall, and the sun-tracking mirrors cover a land area of about 8 acres. 

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