PURPOSE: To easily and inexpensively generate fresh water on the seaside and desert districts, solitary islands, etc., utilizing a solar cell and solar energy by arranging a cooling cylinder, evaporating dish and trough in a greenhouse formed with a transparent body, filling the greenhouse with saturated steam, cooling the steam and accumulating condensed water droplets in the trough.

CONSTITUTION: The greenhouse is formed with a transparent PVC sheet 4. A cooling cylinder 5 having a radiating fin, a trough 6 and an evaporating dish 7 are successively arranged below one another. Seawater is supplied to the cooling cylinder 5 by a submersible pump 2 driven by a solar cell 1, the cylinder 5 is cooled by the seawater, and the seawater is accumulated in the dish 7. The greenhouse is directly heated by the sun, hence the seawater in the dish 7 is evaporated, brought into contact with the fin of the cylinder 5 and cooled, and the condensed water is dropped into the trough 6 and accumulated in a vessel 11 as fresh water. The PVC sheet 4 laid over the V-shaped roof of the greenhouse is cooled by the external air, and the fresh water condensed on the inner surface of the sheet is dropped into the trough 6.