Abstract:
The objective of this work is to analyze the technical feasibility of solar pumping systems for their expansion in small-scale irrigation in Tillabéri (Niger Republic). The study area concerned all irrigable listed land in that region. The agro-climatic data, contained in the CLIMWAT 2.0 software, allowed to analyze the environment’s solar energy potential on the one hand, and to estimate the tomato, onion, potato and pepper crops water needs by using the CROPWAT 8.0 software, on the other hand. The solar energy requirements, the power of the photovoltaic generator and the number of required panels by the generator to cover the crops water needs during the peak periods, were determined according to the total hydraulic head to be overcome by the pumping system. This results in monthly average sunshine duration values ranging from 7 hours/day in August to 8.5 hours/day in May. The solar energy is 5 kWh/m2/day in December and 6.22 kWh/m2/day in May. The required energy for the irrigation water lifting during the peak periods, the power of the photovoltaic generator and the number of panels required for the generator varied according to the total hydraulic head (Ht) across different crops. Thus, for Ht between 15-120 m, the required energy varies between 3.62-29.00 kWh/day/ha for tomato; 3.56-28.48 kWh/day/ha for onion; 3.23-25.83 kWh/ha/day for potato and 2.74-21.89 kWh/day/ha for pepper. The required power for the photovoltaic generator varies between 1.08-8.64 kW/ha for tomato; 1.06-8.48 kW/ha for onion; 0.96-7.69 kW/ha for potato and 0.82-6.52 kW/ha for pepper.
Likewise, the number of panels varies between 4-27 panels/ha for tomato and onion; 4-25 panels/ha for potato and 3-21 panels/ha for pepper. These results indicate a considerable solar energy potential, characterized by a relatively high duration of sunshine throughout the year and a high energy production capacity per square meter. This would promote the proper functioning of the solar pumping systems as well as their expansion. However, the cost of acquiring the panels required for the generator can be an obstacle to the expansion of this technology, especially in conditions of considerable groundwater depth. |
