PERFORMANCE EVALUATION OF SOLAR POWERED IRRIGATION SYSTEMS IN THE NORTHERN REGION OF GHANA

Abstract

Performance of a solar powered irrigation systems in the Northern Ghana was evaluated in this study. Solar powered water application systems (drip, spray tube and sprinkler irrigation systems) were evaluated using performance indicators. Coefficient of variation (CV), emission uniformity (EU), emitter flow variation (Qvar) and mean application rate (MAR) were evaluated for the drip irrigation system for different water levels in the tank. Uniformity Coefficient of (CU), Distribution Uniformity (DU), Mean Application Rate (MAR) were evaluated for the spray tube and sprinkler irrigation systems. Pressures in the submain line of the drip irrigation system (DIS) were 4.7 psi, 5.3 psi and 6.4 psi at tank water levels of 3.3 m, 3.75 m and 4.5 m high, respectively. Results of irrigation efficiencies were high with drip, spray tube and sprinkler systems recording 87 %, 80.30 % and 73.70 % respectively. The EU for the DIS ranged from 87 - 88.1 %; Qvar ranged from 17.1- 18.7 %; CV ranged from 0.05 - 0.058 and MAR ranged from 0.60 -0.9683 l/h. The CU, DU and MAR were found to be 83.1 %, 80.5 % and 15.5 mm/h respectively for the spray tube irrigation system (STIS) and 82.5 %, 73.7 % and 4.1 mm/h respectively for the sprinkler irrigation system (SIS). The life cycle of the solar powered irrigation was estimated to be 25 years. The life cycle costs (LCC) for the drip, spray tube and sprinkler irrigation systems were estimated to be 165,259.63 USD, 205,703.99 USD and 223,785.44 USD respectively. The drip irrigation system recorded high capital, operation, maintenance and repair cost, replacement cost; followed by the sprinkler irrigation and spray tube irrigation. It is suggested that the drip irrigation should be used when the water source is scarce since it saves water more than the sprinkler and spray tube irrigation systems. A flow meter should be installed on the drip irrigation system to measure the volume of water applied in the field, since mean application rate changes due to water level in the tank.