Solar collectors are special kinds of heat exchangers that transform solar radiation energy to internal energy of the transport medium. The major component of any solar system is the solar collector.
What are the applications of solar energy collectors?
These include water heating, space heating and cooling, refrigeration, industrial process heat, desalination, thermal power systems, solar furnaces and chemistry applications. It should be noted that the applications of solar energy collectors are not limited to the above areas.
An energy efficient solar collector should absorb incident solar radiation, convert it to thermal energy and deliver the thermal energy to a heat transfer medium with minimum losses at each step. It is possible to use several different design principles and physical mechanisms in order to create a selective solar absorbing surface.
The two major types of collectors, i.e. flat-plate and concentrating are examined separately. The basic parameter to consider is the collector thermal efficiency. This is defined as the ratio of the useful energy delivered to the energy incident on the collector aperture. The incident solar flux consists of direct and diffuse radiation.
What does a solar collector do?
Solar collectors form the core of a solar thermal system. As their name suggests, they collect the sun's rays. This is then followed by conversion into usable heat, which can then be used to heat domestic hot water or as a central heating backup in the home.
What factors are not included in a solar collector selection?
They do not include incidence angle effects, which vary throughout the year, heat exchanger effects, probabilities of occurrence of Ti, Ta, solar irradiation, system heat loss, or control strategies. Final selection requires determining the long-term energy output of a collector as well as performance cost-effectiveness studies.
Which cover material is most commonly used in solar panels?
Glass remains the most frequently used cover material because it transmits as much as 90% of the incoming short-wave solar radiation, while, particularly for glass with low iron content, little of the long wave thermal radiation emitted by the absorber is transmitted out of the collector.