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CHAPTER TWO
LITERATURE REVIEW
Introduction
:
A solar tracker is a device used for orienting
a photovoltaic array solar
panel or for concentrating solar reflector or lens toward the sun. The position of
the sun in the sky is varied with both seasons and time of day as the sun moves
across the sky. Solar powered equipment work best when they are pointed at the
sun. Therefore, a solar tracker increases how efficient such equipment are over
any fixed position at the cost of additional complexity to the system. There are
different types of trackers. Extraction of usable electricity from the sun became
possible with the discovery of the photoelectric
mechanism and subsequent
development of the solar cell. The solar cell is a semiconductor material, which
converts visible light into direct current. Using solar arrays, a series of solar cells
electrically connected; there is generation of a DC voltage that can be used on a
load. There is an increased use of solar arrays as their efficiencies become higher.
They are especially popular in remote areas where there is no connection to the
grid. Photovoltaic energy is that which is obtained from the sun. A photovoltaic
cell, commonly known as a solar cell, is the technology used for conversion of
solar directly into electrical power. The photovoltaic
cell is a non-mechanical
device made of silicon alloy.
The photovoltaic cell is the basic building block of a photovoltaic system.
The individual cells can vary from 0.5 inches to 4 inches across. One cell can
however produce only 1 or 2 watts that is not enough for most appliances.
Performance of a photovoltaic array depends on sunlight.
Climatic conditions
like clouds and fog significantly affect the amount of solar energy that is received
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by the array and therefore its performance. Most of the PV modules are between
10 and 20 percent efficient [3].
Figure 2.1 Solar Cell
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