Why Is A Tracking Concentrator Better Than A Flat Panel For Heating A Home?

By Author: Rockey
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Heating is a major consideration in designing and heating a home. There are many options to choose from. One may heat with gas, geothermal, electricity or solar energy sources. This article focuses on a comparison between two types of solar thermal energy; stationary flat panels and tracking concentrators. The application considered in this case is that of heating a home. Dwellings must be kept at the proper temperature in many places around the world for the comfort of the inhabitants; solar thermal energy can be used for this purpose.

The American Society of Heating, Refrigerating and Air-Conditioning Engineers define thermal comfort as the state of mind in humans that expresses satisfaction with the surrounding environment. The variables for this state are heat conduction, radiation, convection as well as evaporative heat loss. More specifically this includes clothing insulation and personal activity level, as well as air temperature, humidity, air movement and floor temperature. Solar thermal energy can be used to maintain air temperature to ensure proper levels of thermal comfort.

Once a builder or homeowner ...
... has decided to use solar power for heating one’s home; the choice now remains for which type of system to install. The key to a good solar thermal energy system is efficiency. One should exclude using the photoelectric effect to fuel traditional electric heaters; this is simply very inefficient. A solar thermal energy system can be hooked up to the house for maximal energy gains.

Flat panel collectors can be used within a solar power system to fuel a home’s heating requirements. Their design involves a black absorber, covered with a transparent cover and a heat transfer fluid. In most cases they are stationary. This means that a flat plate collector will only operate at peak efficiency for a small window throughout the day; this is when the sun forms a 90o angle with the plate. Tracking systems can be rigged up to a flat plate collector, but for a solar thermal energy system, this can be quite costly and inefficient. Each individual solar thermal collector must have its own tracking system.

By contrast, a concentrator offers much greater efficiency with its tracking potential. One single parabolic dish concentrator can glean as much solar thermal energy as 15 or more flat plate collectors. These tracking concentrators basically work to increase the sun’s power and apply its energy towards a heat absorber. Instead of having multiple flat plates absorbing heat from one sun, there is one absorber effectively absorbing the heat of hundreds of suns. With this system valuable roof or ground space is saved, reducing the solar power system cost and size.

The choice between the two systems boils down to the following: whether or not a builder wants an efficient, sleek and flexible solar thermal energy setup or a limited, low temperature installation. Parabolic solar concentrators, such as the SolarBeam, offered by Solartron Energy Systems fill the former category.