The physics of the solar pond

Abstract Solar radiation can effect a considerable temperature rise in non-convecting ponds of about a meter depth. Salt water at temperatures near 100 deg C can be withdrawn for utilization from the bottom of the ponds. The efficiency of the pond as a collector of solar energy is then greater than 20 percent and about 4 percent of the ineident energy can be converted by a Carnot engine to electrical energy. The pond is maintained non-convecting when there is a temperature gradient in the pond, with the bottom warmer than the top, by means of a salt concentration gradient that assures the greater density of the lower regions.