Previous works

LITERITURE REVIEW

Previous works

Solar tracker is a device for orienting a day lightning reflector , solar photovoltaic panel or concentrating solar reflector or lens towards . the su position varies in the sky both with the season and time of the day as the sun moves. Solar power works best when pointed at or near the sun, so the solar tracker can increase  the effectiveness of such equipment over  any fixed position, at the cost of additional system complexity. There are many type of solar tracker and varying costs, sophistication and performance. One well-known type of solar tracker is heliostat, a moveble mirror that reflect the moving sun to a fixed location.

example of solar tracker prototype

Azimuth-altitude dual axis tracker - 2 axis solar tracker, Toledo, Spain.

Basic concept

Sunlight has two components, the "direct beam" that carries about 90% of the solar energy, and the "diffuse sunlight" that carries the remainder - the diffuse portion is the blue sky on a clear day and increases proportionately on cloudy days. As the majority of the energy is in the direct beam, maximizing collection requires the sun to be visible to the panels as long as possible.The energy contributed by the direct beam drops off with the cosine of the angle between the incoming light and the panel. In addition, the reflectance (averaged across all polarizations) is approximately constant for angles of incidence up to around 50°, beyond which reflectance degrades rapidly