Solar Thermal Collector Efficiency Equation

Solar collectors solar collectors are the key component of active solar heating systems.

Solar thermal collector efficiency equation. Ti inlet fluid temperature to the collector ºf ta ambient air temperature surrounding the collector ºf i solar radiation intensity striking the collector btu hr ft2. Solar thermal collectors are classified by the united states energy information administration as low medium or high temperature collectors. Solar collector performance variables can be used to promote the performance of a solar collector in particular the peak efficiency value is used. Solar thermal energy ste is a form of energy and a technology for harnessing solar energy to generate thermal energy for use in industry and in the residential and commercial sectors.

The inlet temperature of 40 c with a flow rate of 3 liters minute gives a range of efficiency values of glazed flat plate solar collector of 32 64 unglazed flat plate solar collector is 26 53. The solar energy collection efficiency of both thermal collectors and photovoltaic collectors is defined as the ratio of the rate of useful thermal energy leaving the collector to the useable solar irradiance falling on the aperture area. Thermal efficiency of the collector is an important parameter to consider in this kind of analysis as it creates the basis for comparison of different materials and modifications of. Simply stated collector efficiency is.

A solar thermal collector collects heat by absorbing sunlight the term solar collector commonly refers to a device for solar hot water heating but may refer to large power generating installations such as solar parabolic troughs and solar towers or non water heating devices such as solar air heaters. Thus the thermal efficiency of the solar collector is η coll q r i t 0 a a. Useful energy absorbed solar energy thermal losses. Obviously the higher the useful energy output from a particular design the higher the expected efficiency.

They gather the sun s energy transform its radiation into heat then transfer that heat to a fluid usually water or air. The solar thermal energy can be used in solar water heating systems solar pool heaters and solar space heating systems. A value of 60 80 is common for most thermal solar collectors but this value needs to be taken with a grain of salt with the surface area it is based on considered. This can make a fair comparison of one collector to another rather difficult since panels come in different sizes are made of different materials and can be used in innumerable different climates and temperature applications.

Solar thermal collectors are either non concentrating or concentrating. The solar collector can be divided in two subsystems. Low temperature collectors are generally unglazed and used to. P ti ta i p inlet fluid parameter.

The solar collector efficiency represents the ratio between the heat absorbed by the solar receiver q r and the incident solar radiation i t0 normal on the collector s aperture of area a a.