Solar Water Pumping Advances and Comparative Economics

AbstractSolar power is a natural and symbiotic choice for water pumping. It is one of the most economically attractive solar energy applications with direct drive PV systems often providing decades of reliable service. There is a good match between seasonal solar resource and seasonal water needs. Photovoltaic water pumping (PVWP) systems can meet a wide range of needs and are relatively simple, reliable, cost competitive, and low maintenance. A typical system configuration includes a PV array, pump, controller, inverter (for ac), and overcurrent protection. Until recently PVWP was competitive for only relatively small pumping loads. Over the past decade, the competitiveness of PVWP has increased dramatically, significantly expanding the range of pumping loads/requirements where PVWP is competitive.There have been dramatic price reductions in PV modules over the past decade, by over 80%, while prices for competing gasoline or diesel fuel have risen by over 250%. PVWP is most cost-effective for steady pumping needs such as community water supply or livestock watering—both year-round pumping requirements in most cases, and for irrigation water pumping when irrigation takes place much of the year. New technological innovations in controller technology has expanded PVWP range by an order of magnitude to ∼25kW, with 100kW expected in the near future. Similarly, more efficient helical rotor water pumps have been developed that are reliable and simple to operate