ABSTRACT

Solar ponds are storage/collector devices at the lower end of the scale. These are large area, inexpensive solar collectors. When a pond of water is heated, the warmest water comes to the surface (being lighter) and rapidly dissipates its heat by convection and evaporation, then it sinks. An undesirable thermosiphon circulation develops. This can be prevented by using very salty water for a bottom layer and a fresh water upper layer. The salty water, even at near boiling-point temperatures, is heavier than the fresh water and remains at the bottom.