Solar Water Heaters based on Flat Plate Collectors

A solar water heater consists of a collector to collect solar energy and an insulated storage tank to store hot water. Here the solar radiation is absorbed by flat plate collectors which consist of an insulated outer metallic box covered on the top with glass sheet. Inside there are blackened metallic absorber (selectively coated) sheets with built in channels or riser tubes to carry water. The absorber absorbs the solar radiation and transfers the heat to the flowing water.