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Abstract At this study an evaluate the performances of a direct photovoltaic pumping system based on an asynchronous motor driving a centrifugal pump. The system was tested and evaluated while operating under Inshas climatic conditions. Field experiments were conducted in the Farm of Soil and Water Research Department, Nuclear Research Center, located at Inshas city, Sharkia Governorate which represents sandy soil conditions, Atomic Energy Authority, Egypt. The latitude and longitude of the experiment site are 30o 24` N, 31o 35` E, respectively, Egypt. Based on the results conclusions are as follows: • Solar radiation also differs according to seasons, in winter the sun becomes lower in the sky and higher in summer because sun ray’s angle changes due to the earth’s tilt angle. • PV generator was tested under the Inshas desert climate. The fluctuation of solar intensity and ambient temperature influenced the generator output current and voltage respectively as mentioned by the manufacturer. The day length and sun hours affected the total daily power harvest through the months. • Generated electric power was measured at different times during test days starting 8:00 a.m. to 16:00 p.m.. The results show that generated electric power increases with increasing solar radiation intensity which means that generated electric power of PV module depends on solar radiation intensity at different values ranged at 620 W/m2 in the morning and 438 W/m2 at afternoon and 1074 W/m2 at midday. • Variation solar radiation intensity affects in generated electric power. The highest solar radiation intensity was obtained at midday when sun ray is perpendicular on the surface. • Module temperature was measured as a function of time during test days starting 8:00 a.m. to 16:00 p.m. in months January, February, March, April and May. (PV) performance decreases with the increase of module temperature. Module temperature and solar radiation intensity play a big part in the photovoltaic conversion process. the change of output voltage average for every module temerature degree kelven was (-0.07%V/C) at 34.7ºC. On the otherhand, it was (-0.24%V/C) at 43.8oC and it was (-0.36%V/C) at 51.8oC, while manufacturer it was (-0.35%V/C). The change of generated electric power average for every module temerature degree kelven was (-0.27%W/K) module temperature at 34.7ºC. On the otherhand, it was (-0.27%W/K) at 43.8oC and it was (-0.40%W/K) at 51.8oC, while manufacturer mentioned that it was (-0.45%W/C). • Module efficiency indicate graduate increase with increase solar radiation intensity. Module efficiency average values reached to be 14.70% at 12:00 p.m. when the average of solar radiation reaches to be 1074 W/m2 at midday for months March, April and May for months March, April and May. • The increase of hydraulic power as a result of the increasing in solar radiation intensity for months March, April and May. Hydraulic power average values reached to be 161W at 12:00 p.m. when the average of solar radiation reaches to be 1074 W/m2 at midday for months March, April and May. • Pumping system efficiency indicate graduate increase with increase solar radiation intensity. Pumping system efficiency average values reached to be 22.97% at 12:00 p.m. when the average of solar radiation reaches to be 1074 W/m2 at midday for months March, April and May. for months March, April and May. • Overall system efficiency indicate graduate increase with increase solar radiation intensity. Variations in the solar radiation intensity change the overall efficiency. Overall system efficiency average values reached to be 3.38% at 12:00 p.m. when the average of solar radiation reaches to be 1074 W/m2 at midday for months March, April and May. for months March, April and May.from the obtained results, it can be evaluated the performances of a direct photovoltaic pumping system based on an asynchronous motor driving a centrifugal pump and it should be increase during the summer season. It was also found that the lowest overall system efficiency of the solar pumping system reached to be (2.92%) while the highest overall system efficiency of the solar pumping system reached to be (3.93%) at 12:00 p.m. for May. So it should be recommending the followings: 1. This study recommended a strong way such as solar powered pumping system for small scale areas suitable as an alternative to fossil traditional fuels. 2. Considering reduction of power output from the grid system leads to increase the demand for the solar generators to compensate. 3. Economically, its recommended to use solar generators instead of diesel one for remote areas. and the study showed a lot of benefits for using renewable energies. 4. Using soil moisture measurement can help to predict the actual water movement in soil. 5. Matching system components and using high efficient parts will help to maximize overall system efficiencies. |