5. Conclusion
The aim of this work is to determine the effect of pumping head on PVWPS using the optimum PV array configuration, adequate to supply a DC Helical pump with an optimum energy amount, under the outdoor conditions of Madinah site. Four different pumping head have been tested (50 m, 60m, 70 m and 80 m). The best sys- tem efficiency has been obtained for the head of 80m which is rec- ommended for SQF submersible pump for a deep head. System efficiency as a function of system pumping head and solar irradia- tion was investigated. It is found that system efficiency increases with increasing solar radiation until the pump reached their max- imum power. Also, system efficiency increases with decreasing pumping head during low solar radiation defined in this work as the first and the third states of PV pumping system. During the maximum power (high solar radiation), we have found that the optimum pumping head correspond to the best average system efficiency which is obtained for the head of 80 m. This head is con- sidered as the optimal pumping head profile for the considered PV pumping system. Also, increasing PV array size generally increases flow rate and system efficiency. In the future work, we will use a centrifugal pump for the same well under the same outdoor conditions of Madinah site. We will compare the daily flow rate given by two types of pump (Helical pump and Centrifugal pump) during the sunny daylight hours.
Acknowledgements
The authors would like to thank the International Centre for Theoretical Physics (ICTP), Trieste (Italy) for providing the materi- als and the computers facilities for performing the present work. This work was also supported by the Dean of research of Taibah University under Project number No.: 431/613. All collaboration works are gratefully acknowledged.
References