Solutions for adapting photovoltaics to large power irrigation systems for agriculture

Abstract

The adaptation of the mature PV water-pumping technology to large power irrigation applications requires the problems associated to PV power intermittencies and matching PV production with the irrigation needs to be resolved. This paper presents the innovations developed, implemented and tested in a PV irrigation prototype installed in a real well at an Irrigator Community in Alicante, Spain. The innovations eliminate the intermittences due to passing clouds, reducing the PV power by 80% in just few seconds without batteries, just using control algorithms in the frequency converter, avoiding water hammers and overvoltages. A North-South horizontal axis tracker has been used to extend the number of hours of irrigation per day and to provide daily constant profiles of PV power during the irrigation period. Moreover, the use of this tracker allows the nominal power of the PV generator to be reduced by 45% as compared to a fixed structure for the same volume of water. The analysis of the economic feasibility of the prototype compared with the cost of grid electricity shows savings of 60%. This prototype has been operating in the South of Morocco delivering more than 235 m3/day for the last three years.