Active solar

Solar hot water systems use pumps or fans to circulate fluid (Often a mixture of water and glycol to prevent prevention freezing during winter periods) air gold through solar collectors , and are therefore classified under active solar technology.

Some of the basic benefits of active systems (usually electrical) can be used to maximize their effectiveness. For example, a passive solar thermal array which does not rely on pumps and sensors only when a certain amount of internal energy is built into the system. The use of sensors and pumps, a relatively small amount of energy, can be used to increase the temperature of a battery. Controls also allow a greater variety of choices for utilizing the energy that becomes available. For example, a solar thermal array could heat a swimming pool on a relatively cool day when heating a domestic hot water cylinder was impractical due to the different stored water temperatures.

Disadvantages of active solar systems can not be avoided (probably rendering them useless) and that controls require maintenance.

Most solar collectors are fixed in their array position mounting, but can be a higher performance if they track the path of the sun through the sky (though it is unusual for thermal collectors to be mounted in this way). Solar trackersUsed to orient solar arrays can be driven by passive or active technology, and can have a significant gain in energy yield over a year when compared to a fixed array. Again passive solar tracking would rely on the thermo-dynamic properties of the materials used in the system rather than an external power source to generate its tracking movement. Active Solar Tracking would use sensors and motors track the path of the sun across the sky. This action may be caused by the presence However, some of these systems can be used in the light of a light source.