| dc.description.abstract | Remote areas do not have access to electricity and therefore mostly use diesel water pumping systems (DWPS) to irrigate their crops. It has been, however, found to be expensive and unsustainable in the long run especially to the environment. A good alternative to replace the DWPS in remote areas with low or no access to the grid is the solar water pumping systems (SWPS) particularly for food production. Solar Powered Irrigation Systems (SPIS) performance is affected by environmental conditions that determine the crop water requirements and the solar intensity influencing the production by PV arrays, which exhibit temporal variability. The aim of the study was to design a system for irrigation of maize in hot arid areas. CROPWAT is used to determine the irrigation water requirement necessary for the preliminary design of the system while PVSYST provides the optimal orientation of the PV array. A dynamic modelling of the system is used to assess its performance over the growing period of maize, a Kenyan staple food grain. The water demand was found to be higher in the hot arid areas having peak irrigation requirement of 96.8 m3 and resulted in a slightly bigger system with its performance varying during the growing season. From the economic feasibility of the system evaluated it was found that the SPIS had higher initial costs, but was cost effective and more profitable to run in the long run. The cost of the energy generation system accounted for 43% of the initial capital costs (ICC) in SPIS as compared to 23% in DPIS. Both systems had nearly the same internal rate of return (IRR) with externality costs not accounted for. SPIS is feasible for deployment in hot arid climate and is expected to provide an alternative and help the semi-arid and arid areas cope with the dangers of food insecurity caused by reliance on unreliable rainfall for farming. | |
