An-Najah Staff

 Two similar PV powered water pumping systems (PVPS) with a programmable control system, which enables matching between the loads (pumps) and the generated PV power according to solar radiation intensity, are treated in this paper. Testing results show an annual gain of 7.4% in water pumped through using the control system. Moreover, up to 16% increment in daily water pumped, especially in winter days of moderate solar radiation (≈2.8 kWh/m2.day), has been measured. This means that a considerable reduction of the water cost is achieved and thereby the feasibility of PVPS is increased. Further increments of total system efficiency achieved by utilizing PV modules of higher efficiency and by mounting the PV array on a support structure with adjustable tilt angle are discussed. Decreasing the hydraulic output of the pumping system, due to the increase of temperature in summer, is demonstratedthrough field testing results.