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 elimínate 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 flxed 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 m 3 /day for the last three years.

Standalone Photovoltaic Direct Pumping in Urban Water Pressurized Networks with Energy Storage in Tanks or Batteries

“…Additionally, their use in irrigation networks has been explored [14][15][16] because of their energy consumption reduction [17,18]. Some approaches have focused on standalone direct pumping photovoltaic systems without storage systems [19,20], on solving the shadows passing over the generator [21], on investigating the effect of variable solar radiation on a PV based system [22] and on coupling irrigation scheduling with solar energy production [23]. A tool to synchronize the energy produced and the energy required in an irrigation network while minimizing the number of photovoltaic solar panels was developed [24], which requires that operators control the water and energy demand to fit the energy required by crops to the energy produced by photovoltaic (PV) panels.…”

Large power hybrid PV pumping for irrigation

“…TWh worldwide [29], with the southern Europe representing almost 40% of this consumption [30], which means a potential market of 16 GWp of PV irrigation systems in this region [31].…”

“…For instance, in Morocco, in 2011, irrigated land represented 5% of the UAA [32] and, in 2009, 15% of the energy consumed in the country was devoted to agriculture and forestry [19]. According to the Ministry of Energy, Mines, Water and Environment, cited in [31], the annual electric consumption in this region is estimated to yield 2500 GWh, which leads to a potential market of PV irrigation system of 1.5 GWp.…”

“…At that time, he had a Non-ove rnmental Organization in Mali, called "Mali Aqua Viva", which, among other things, supported the installation of hand pumps for drinking water. Excited with the good performance of the solar pump in Corsica [31], he introduced the first PV pump in Africa in 1977 [34].…”

“…For example, the largest system presented in the review of Wazed has 11 kWp [63], while the largest one in the Sontake review has 15 kWp [64]. In [31], a 20 kWp system in Tizi (Morocco) is described (see Figure 7). Therefore, it can be said that the experience in PV water pumping systems for irrigation is limited to low-power [31].…”