الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
One of the most important difficulties in using photovoltaic systems is the low energy conversion efficiency of PV cells and, furthermore, this efficiency decreases further during the operational period by increasing the cells temperature above a certain limit. To increase the efficiency of PV systems one way is cooling them during operation period. In the first part of the experimental work three cooling systems: film water cooling, direct contact back water cooling and combining film - back cooling are presented and analyzed Experimental measurements for both cooling and non-cooling modules for the three cooling experiments indicate that the temperature of the cooling photovoltaic module is lower up to 18, 16, 25 for film cooling module, back cooling module and combined film – back cooling module respectively compared to non-cooling module. Reducing the module surface temperature causes an increase in module output power and module efficiency. The results show that the daily output power of the PV cooling module increased up to 22 %, 35% and 29.8% for film cooling module, back cooling module and combined film – back cooling module, respectively compared to non-cooling module In the second part of the experimental work , two axis sun-tracking systems is designed whereby the movement of a photo-voltaic module is controlled to follow the Sun’s radiation using a programmable logiccontroller PLC) unit. It is found that the daily output power of the PV is increased up to 29.3% in comparison with that of a fixed module. Finally an active cooling system is designed and conducted to cool the tracking module at which an absorber system consists of copper pipe welded with copper foil ii is attached underneath the PV module to allow water flowing below the module surface, the water absorbed heat from the copper foil which is absorbed previously from the surface of the cell causing reduce in module surface temperature. The cooling experiment indicate that the surface temperature of tracking module reduced Up to 15 with 7 average daily reduced compared to the non-cooling tracking module Hybrid cooling system for the tracking module increased the daily output power of the PV cooling module up to34.5% compared to non-cooling fixed module, with increased 5.2 % over than that produced from non-cooling tracking module Three dimensions k- model using FLUENT (Version 6.3.26) is studied to simulate the heat transfer and the flow characteristics around photovoltaic The experimental results for output power and efficiency are less than the predicted results; this is due to some losses of many sources that not considered in the correlations, such as heat losses in resistor panel, losses due to module connections and other losses.