Abstract

The sustainability (SAI and AIR), cost (MBR, PCR, ECR and CPA) and energy consumption (SEC and RAI) performance of Bagarasi pumping irrigation system (BPIS) and Turkelli pumping irrigation system (TPIS) pumped irrigation systems were determined according to these 8 indicators. Also, the potential energy saving and repayment period on investment for replacing the standard electric motors with high efficiency motors was determined. Calculated values of SIA for BPIS (445.9%) and TPIS (36.7%) were below the ideal. Calculated actual values of AIR for BPIS (13.7 ha km^-1) and TPIS (15.4 ha km^-1) were lower than indicator values calculated according to the system’s projected values. These indicators showed that the system was not sustainable with regard to irrigated area and infrastructure. MBR values for BPIS (7.3%) and TPIS (6.2%) were lower than the ideal. ECR value of BPIS (27.5%) was lower than that for TPIS (55.5%). The value of PCR for BPIS (61.3%) was higher than that for TPIS (34.3%). Calculated CPA values for both TPIS (178 $ha^-1) and BPIS (513 $ha^-1) were higher than the indicator values calculated according to the system’s projected values. Cost indicators showed that in both systems maintenance work was inadequate, energy expenditure was higher than other forms of expenditure and that the unit price of irrigation water was high. SEC_a and SEC_i values were0.051 kWhm^-3 and 0.020 kWhm^-3 respectively for BPIS and 0.105 kWhm^-3 and 0.029 kWhm^-3 for TPIS. RAI values for BPIS (39.80%) were higher than that for TPISs (27.53%). In addition, RAI values for the year after a compensation system was installed for BPIS did not exceed the projected limit. These indicators show that the use of energy in TPIS was relatively good compared to BPIS. The use of high efficiency motors secured a 10.87 - 13.89% energy saving in the systems. The repayment period for the motors was less than 2 years. To improve system performance, efficiency in the transmission and use of water must be improved and high efficiency motors must be used to power the pumps. Also, if energy monitoring and control systems are installed which operate remotely and in real time, these will increase the efficiency of energy use.

Key words: Performance, irrigation, water pumping, energy efficiency, Bagarasi, Turkelli.