Performance and Cost Comparison of Photovoltaic and Diesel Pumping Systems: In Central Rift Valley of Ethiopia

Abstract

Diesel pumps have extensively used for irrigation water pumping. However, this causes challenges both in terms of economic factors (fuel costs) and environmental impacts (emits air pollution). An alternative solution is using renewable energy sources. In this regard, a battery less solar PV energy system was designed and evaluated was designed and evaluated for the geographic location and metrological data of Dugda woreda, representing the central rift valley of Ethiopia. Performance testing were conducted on sunny days of April month and with time intervals of from 9:00 am to 5:00 pm, again the respective solar radiation ranges between 385.8 to 862.2 W m^(-2) h^(-1). The solar photovoltaic pumping has been evaluated with the head levels of 10, 12, 15, and 18 m. Accordingly the result showed that, PV system size can irrigate a tomato field of 0.33-0.75 ha with a mean daily water use of 8.7 and 17.4 m^3 〖day〗^(-1) at head levels of 10 and 18 meters, respectively. After evaluation, the maximum water flow rate has been at the midday day from 12:00 am to 1:00 pm. Comparative economic evaluation of the solar-powered water pump system and diesel pump devices were done using cycle cost breakdown and the cost of water per unit volume. Thus the long term economics of water pumping using solar photovoltaic and diesel pumping systems showed a cost of 1.33 〖ETB m〗^(-3) and 3 ETB m^(-3), respectively. The result demonstrated that photovoltaic water pump systems are more affordable for the long-term services of small to medium-scale farms than gasoline water pumps.