Evacuated Tube Solar Collectors: A Review

In the present review paper, the existing evacuated tube solar collectors are studied with their applications. The most important feature of renewable energy is that it can be harnessed without the release of harmful pollution.one of most promising renewable energy source is Solar energy, the solar radiation incident on the surface of the earth can be conveniently utilized for the benefit of human society. Solar energy collectors act as heat exchangers that convert the solar radiation energy into internal energy of the transport medium. The evacuated tube solar collectors are common and can achieve higher temperature than flat plate collector ranging from 50-130 ?. Heat extraction from long thin absorber is the main problem with evacuated tube solar Collector, different methods are used to extract heat from evacuated tubes. Some unique advantages of evacuated tube solar collector over other types of collector are listed. The available literature is reviewed to understand the construction, arrangement and application of evacuated tube solar collector.