The use of solar thermal energy for self- and passive control of sedimentation in large reservoirs

Abstract

Solar therm al energy and its possible role with regard to self- and passive con-trol sedimentation in large reservoirs behind dams is discussed. It is knownthe impact caused by large re servoirs because the drastic reduction of the natu-ral water flow velocity of rivers and the consequent sediment trapping. Sedi-ment trapping in the reservoir has not only an environment impact becausereducing the sediment transported to the deltas of rivers but also limits theuseful lifetime of the dam for flood control, water supply, and hydropowergeneration. However, because the large surface of the reservoir together withthe free available solar insolation a self- and passive sedimentation controlmethod may be possible. The idea is simple, namely. Likewise solar ponds takeadvantage of the ultraviolet solar energy in deep waters, then in the bottom ofthe reservoir, the ultraviolet radiation could be collected by deliberately fur-rowing the reservoir floor. The mild heating of the floor will result into mildconvective currents which can recirculate the sediment continuously. Utilizinga simplified physical model a first assessment of the idea is performed