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A concentrated solar power plant (CSP) works like a coal steam power plant, with the difference that concentrated solar power is used for steam production, instead of coal. Large mirrors are positioned in such a way that they reflect and concentrate the sunlight onto a certain point much like capturing sunlight through a magnifying glass.
Klaus Bernhard Hofmann: There are no ratios definied in this phase of DII. But current plans call for CSP to play a major role for Desertec. Concentrating solar power is the most economical way to generate solar power and has the longest track record of large-scale commercial renewable electricity generation in deserts. For over twenty years, the first parabolic trough power plants in the Californian Mojave Desert have been reliably supplying over 300 MW of dispatchable peak power. Parabolic troughs are today the most common and most mature solar concentration technology.
Q: How can we be sure that Desertec will produce a reliable quantity of current without risk of a major blackout?
How will the CSP-plants be cooled? The Andasol plants need 800.000 m³/year cooling water
Is the option for dry cooling operation of CSP-plants considered in the financial budget? Does this cooling option, with its higher investment and lower plant efficiency, still ensure a future cheap electricity price?
— Michael NOLL, Freudenberg Dichtungs- und Schwingungstechnik GmbH & Co. KG
Response from Manfred Engelhard:
Not everywhere like in Andasol we have water available for cooling. In case of water shortage, a general possibility is a dry cooling facility for the power plant, which uses surrounding air as cooling media. Dry cooling will slightly decrease the efficiency of the power block in comparison to wet cooling.
Dry cooling will most probably be the option as the cooling solution for areas where water is too precious to use it for cooling. Financial
models will respect invest cost, parasitic loss and maintenance cost of dry coolers.
Since the overall efficiency of solar thermal power plants are furthermore developed at the moment, electricity price will be still in the range. Higher temperatures on heat transfer media will be one development goal that can be reached soon and can contribute to higher plant efficiencies.