Today, solar cells are one of the most important applications of solar energy. But these solar cells face a serious problem because its efficiency cannot exceed 20%. This means solar cells are characterized with high cost or low quality. So we aim to make the sun rays to be perpendicular to plate face. This can be achieved by developing a device that can track the sun all day accurately and keep it in the perpendicular direction with respect to the solar cells plate. This device is called “Astrological Sun Tracker”.
The sun tracking became of high necessity for increasing the efficiency and reducing the cost of photovoltaic systems and solar concentrators. This system is used for maximizing the normal incident direct solar radiation on the surface of these devices. This is essential in solar water pumping for irrigation and power generation.
In the present study, a new prototype of Astrological Sun Tracker is designed, constructed and tested. Depending on the Global Positioning System (GPS) and the digital compass, this enables that the astrological sun tracker can be used in different locations all over the world. Astrological Sun Tracker is a mechanical device with a microchip. This device depends on astrological equations with dual axis motion to follow the sun light all the year with high accuracy. The microchip contains a code that can solve astrological equations and get the correct position of the sun. Then, the code determines the motor angles required to direct the solar cells plate towards the sun. It’s expected that this device will have advantages over the existing one (Light Sensor). Some of these advantages are easy to build, better accuracy, simple maintenance and lower cost.
Results show that this astrological sun tracker has a good accuracy for tracking the sun and that the experimental data are closely fit the theoretical results. This astrological sun tracker is also seen to be suitable for the photovoltaic panel used for solar pumping, power generation and the dish type solar concentrators. Regarding its marketability, in 2013, Egypt’s Ministry of Electricity is set to receive bids for a tender by the country’s New and Renewable Energy Authority (NREA) to build a 200 MW PV plant in the southern Egyptian province of Aswan (http://www.pv-magazine.com/news/details/beitrag/egypts-ministry-of-electricity-to-receive-bids-for-first-ever-solar-pv-plant_100012958/#ixzz336exNg5k). Also, there will be 120 MW produced by solar energy in 2015-2016. This means that 322560 mirrors and 11520 concentrated solar panels (CSP) or 480000 solar panels (250 W/panel).