INTRODUCTION As the range of applications for solar energy increases, so does the need for improved materials and methods used to harness this power source. There are several factors that affect the efficiency of the collection process. Major influences on overall efficiency include solar cell efficiency, intensity of source radiation and storage techniques. The materials used in solar cell manufacturing limit the efficiency of a solar cell. This makes it particularly difficult to make considerable improvements in the performance of the cell Therefore, the most attainable method of improving the performance of solar power collection is to increase the mean intensity of radiation received from the source.
There are three major approaches for maximizing powerextraction in medium and large scale systems. They are suntracking, maximum power point (MPP) tracking or both.
Components Required The major components used in this project are •Microcontroller •Motor driver •DC Motor •LDR
Basic Block Diagram Solar panel DCLDR MOTOR MICROCONTROLLER
OBJECTIVE If we could configure a solar cell so that it faces the sun continually as it moves across the sky from east to west, we could get the most electrical energy possible. Going outside to a solar cell every hour to turn it toward the sun might be possible, but this would still not be an efficient method. A photo sensor is employed to control the solar cell tracking system.
TRACKING TECHNIQUESThe two general forms of tracking used are: Fixed control algorithms Dynamic tracking
FIXED CONTROL ALGORITHM In the fixed control algorithm systems, the path of the sun is determined by referencing an algorithm that calculates the position of the sun for each time period. That is, the control system does not actively find the suns position but works it out given the current time, day, month, and year.
DYNAMIC TRACKING The dynamic tracking system, on the other hand, actively searches for the suns position at any time of day (or night).Common to both forms of tracking is the control system. This system consists of some method of Direction control, such as DC motors, stepper motors, and servo motors, which are directed by a control circuit, either digital or analog.
LIGHT SENSOR Light sensors are among the most common sensor type. The simplest optical sensor is a photoresistor which may be a cadmium sulfide (CdS) type or a gallium arsenide (GaAs)type .
The sun tracker uses a cadmiumsulfide (CdS) photocell for lightsensing. This is the least expensiveand least complex type of lightsensor . The CdS photocell is apassive component whoseresistance is inversely proportionalto the amount of light intensitydirected toward it. Cds Photocell Circuit
D.C. MOTORS A DC motor is designed to run on DC electric power. the most common DC motor types are the brushed and brushless types, which use internal and external commutation respectively to reverse the current in the windings in synchronism with rotation. Here DC motor is used to rotate the solar panel in direction of sun where the sun rays fall maximum
• In this project we have used two LDR sensors.•These sensors give analog output.•The analog output is given to the microcontroller.•The micro controller compares the analogvoltage and then decides upon the motion of themotor.•If the light on a particular LDR is greater, thenthe micro controller gives the command to themotor driver to rotate the motor in a directionsuch that the both LDR receives equal light.
A Solar panel (also solar module,photovoltaic module or photovoltaic panel) isa packaged, connected assemblyof photovoltaic cells. The solar panel can beused as a component of a larger photovoltaicsystem to generate and supply electricity incommercial and residential applications. Eachpanel is rated by its DC output power understandard test conditions, and typically rangesfrom 100 to 450 watts. The efficiency of apanel determines the area of a panel given thesame rated output - an 8% efficient 230 wattpanel will have twice the area of a 16%efficient 230 watt panel. SOLAR PANEL
ENERGY STORAGE SYSTEM A capacitor is employed to store the energy generated by a solar panel(by converting solar energy into electrical energy). Now this stored energy is can be utilize any where but in our project we have used to light a LED.
The portions consisted of lightdetection, motor driving ,softwaretracking, and software enhancements.Building and testing smaller sectionsof the system made the project moremanageable and increased efficiencyby decreasing debugging time.
CONCLUSION. A solar tracker is designed employing the new principle of using small solar cells to function as self-adjusting light sensors, providing a variable indication of their relative angle to the sun by detecting their voltage output. By using this method, the solar tracker was successful in maintaining a solar array at a sufficiently perpendicular angle to the sun. The power increase gained over a fixed horizontal array was in excess of 30%.
Future Scope Although there are many reasons to believe that the future of solar energy is bright and coming soon, the answer really lies in the hands of the worlds citizens. In a world largely governed by economics and politics, what ordinary citizens choose to buy and support will dictate the trends of the future. By installing solar panels, donating to research organizations involved in alternative energies, majoring in science or engineering, and voting for measures that give money to alternate energy development, anyone can influence the future of solar energy.