CHAPTER ONE

INTRODUCTION

1.1 BACKGROUND OF THE PROJECT

A solar tracker is a device for orienting a photovoltaic array solar photovoltaic panel or concentrating solar reflector or lens toward the sun. The sun's position in the sky varies both with the seasons (elevation) and time of day as the sun moves across the sky. Solar powered equipment works best when pointed at or near the sun, so a solar tracker can increase the effectiveness of such equipment over any fixed position, at the cost of additional system complexity. There are many types of solar trackers, of varying costs, sophisticationand performance. One well-known type of solar tracker is the heliostat, a movable mirror that reflects the moving sun to a

fixed location. (Pang 2010). But many other approaches are used as well non-concentrating applications require less accuracy, and many work without any tracking at all. However, tracking can substantially improve both the amount of total power produced by a system and that produced during critical system demand periods (typically late afternoon in hot climates). The use of trackers in non-concentrating applications is usually an engineering decision based on economics. Compared to photo voltaic, trackers can be inexpensive. This makes theme especially effective for photovoltaic systems using high-efficiency (and thus expensive) panels.

1.2 STATEMENT OF THE PROBLEM

While the output of solar cells depends on the intensity of sunlight and the angle of incidence, it means to get maximum efficiency; the solar panels

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must remain in front of sun during the whole day. But due to rotation of earth those panels can’t maintain their position always in front of sun. This problem results in decrease of their efficiency. Thus to get a constant output, an automated system is required which should be capable to constantly rotate the solar panel. The Solar Tracking System is made as a prototype to solve the problem, mentioned above. It is completely automatic and keeps the panel in front of sun where we get the maximum output.

1.3 AIMS AND OBJECTIVES

The major aim of this project work is to design a sun tracker that follows through the sun as it moves in the sky.The basic target of this project is to provide the means of solving some existing problems in real life activities of man in order to create simplicity in human’s life. The objective involve, providing simple means of controlling the movement of a device that would follow the sun as it move in the sky. This project is very important in the sense that can be used in application like solar dryer and similar one’s that needs the presence. The circuit uses very simple design approach which makes the work very effective in its operation and of course, cost effective. The entire components used in this design circuit are commonly available.

1.4 SOLAR TIME

Solar time (t s) is based on the 24 hour clock, with 12h00 as solar noon (the time that the Sun is exactly due south - in northern hemisphere, or due north - in the southern hemisphere). The concept of solar time is used in predicting the direction of sunrays relative to a point on the Earth. Solar time is location (longitude) dependent and is generally different from local clock

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