Economic Comparison Between Solar Power and National Grid to Supply Energy for Drip Irrigation System: The Case Study of Pakdasht County

In recent years, the supply of energy for irrigation systems of pistachio gardens in Pakdasht is an important issue. With the implementation of targeted subsidies plan, the price of energy has increased significantly. In these conditions, the use of solar energy is the best solution, especially for areas away from the national electricity grid.

In this study, drip irrigation system was designed for 4 pistachio gardens in Pakdasht with areas of 12, 24, 48 and 96 ha and slopes of 0, 1, 2, 3 and 4%. Irrigation was done in two modes: 24-hour irrigation, 12-hour irrigation, then the annual investment costs of the solar system and the national electricity were calculated.

Comparison cost of solar equipment in 12 and 24 hour irrigation showed that in the slope of 4%, the cost of solar equipment in 24-hour irrigation for 12, 24, 48 and 96 ha were 0.6, 0, 68.45 and 97.36 million Rials more than cost of solar equipment in 12-hour irrigation and the investment cost of mechanical equipment and purchasing pipes in 12-hour irrigation were 9.68, 70.46, 240.93 and 451.25 million Rials more than cost of them in 24-hour irrigation, respectively. In general, total cost of the solar system in 24-hour irrigation is less than 12-hour irrigation. Selected solar system (24-hour irrigation) was compared with a pumping system connected to the national electricity grid. The comparison showed that economic feasibility of solar system is depend on the pumping station power and distance of gardens from the national grid.