The sun provides the energy to sustain life in our solar system. In one year, the earth receives enough energy from the sun to meet its energy needs for nearly a year. Photovoltaic is the direct conversion of sunlight to electricity, it is a beautiful alternative source of energy to conventional sources of electricity for many reasons it is safe, silent, non – polluting, renewable, highly modular in that their capacity can be increased incrementally to match with gradual load growth, it is reliable with minimal failure rates and projected service lifetimes of about 20 to 30 years. It requires no special training to operate, it contains no moving parts, it is extremely reliable and it’s virtually maintenance free, and can be installed almost anywhere.
A photovoltaic system is a complete set of interconnected components for converting sunlight into electricity by photovoltaic process including array, balance of system and load. The intensity of sunlight that reaches the earth varies with time of the day, season, location and the weather condition, the total energy on a daily or annual basis is called Irradiation and indicates the straight of sunshine. Irradiation is expressed in Whm – 2 per day or KWh.m-2 per day. Different geographical regions experience different weather patterns, so the site we live is a major factor that affects the photovoltaic system design, the orientation of the panels, finding the number of days of autonomy where the sun does not shine in the sky and choosing the best tilt angle of the solar panels.
Photovoltaic panels collect more energy, if they are installed on a tracker that follows the movement of the sun although it is an expensive process; for this process they are usually fixed in a particular position with an angle called the tilt angle B. This angle varies according to seasonal variation, for instance, in summer the solar panel must be more horizontal while in the winter, it is placed at a steeper angle.