Take for instance (in a very simplistic way), a body of water on the earth (i.e. a river, ocean, sea, lake ect.). The sun heats the body, causing the water to change from a liquid state into a gaseous state (i.e. evaporation). The water vapour rises to a certain altitude where it begins to condense and form clouds, until such time the water molecules can recombine in a liquid state, and fall producing rain. Considering that water catchments collect the water for drinking purposes - I was wondering if there was an artificial way to speed up this process, and use the suns thermal energy more efficiently, perhaps to produce clean water. For example, to construct a series of light reflecting surfaces, in combination with powerful lenses, to collect the suns rays and superheat an area of sea water. The sea water would be inside a closed tank, where the vapour could be collected and condensed to produce the liquid water (product, for drinking and other similar purposes). Filtration may be needed, however it would be easier to perform this task when the water is in a gaseous state rather than a liquid one, such as desalination. Perhaps the biggest problem is the practial nature of building lenses and reflecting surfaces large enough to catch and direct sufficient thermal energy.