hi.. m vishal and I am a school student . I want a working circuit diagram of sun tracking solar panel using Atmega8 microcontroller. .plz hlp me..I hv to submit my project by end of nxt week.

Sun Tracking System for Solar panel project is made to tracking the Sun at day time for utilizing its solar energy properly for solar panel. The Sun trackers are all-weather, reliable and affordable tracking and positioning instruments. This project orients the Solar Panel toward the sun, so that it can utilize with higher accuracy. Our Sun Tracker system track the Sun by use of sensors and rotate the solar panel by means of stepper motor.

For flat-panel applications, trackers are used to minimize the angle of incidence between the incoming light and a solar panel. This increases the amount of energy produced from a fixed amount of installed power generating capacity. The optics in concentrated solar applications accepts the direct component of sunlight light and therefore must be oriented appropriately to collect energy. Tracking systems are found in all concentrator applications because such systems do not produce energy unless oriented closely toward the sun.


Basic concept

Basically, 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 as a proportion 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.

Even though a fixed flat-panel can be set to collect a high proportion of available noon-time energy, significant power is also available in the early mornings and late afternoons when the misalignment with a fixed panel becomes excessive to collect a reasonable proportion of the available energy. For example, even when the Sun is only 10° above the horizon the available energy can already be around half the noon-time energy levels (or even greater depending on latitude, season, and atmospheric conditions).

Thus the primary benefit of a tracking system is to collect solar energy for the longest period of the day, and with the most accurate alignment as the Sun’s position shifts with the seasons.

As the non renewable energy resources are decreasing, use of renewable resources for producing electricity is increasing. Solar panels are becoming more popular day by day. We have already read a post about how to install solar panel for home. Solar panel absorbs the energy from the Sun and is stored in the battery. This energy can be utilized when required. Utilization of the energy stored in batteries is mentioned in below given applications. Solar panels should absorb energy to a maximum extent. This can be done only if the panels are continuously placed towards Sun direction. So solar panel should continuously rotate in the direction of Sun. This article describes about circuit that rotates solar panel.

Sun Tracking Solar Panel Principle:

The Sun tracking solar panel consists of two LDRs, solar panel and stepper motor and ATMEGA8 Micro controller.

Two light dependent resistors are arranged on the edges of the solar panel. Light dependent resistors produce low resistance when light falls on them. The stepper motor connected to the panel rotates the panel in the direction of Sun. Panel is arranged in such a way that light on two LDRs is compared and panel is rotated towards LDR which have high intensity i.e. low resistance compared to other. Stepper motor rotates the panel at certain angle.

When the intensity of the light falling on right LDR is more, panel slowly moves towards right and if intensity on the left LDR is more, panel slowly moves towards left. In the noon time, Sun is ahead and intensity of light on both the panels is same. In such cases, panel is constant and there is no rotation.