Performance evaluation and economic analysis of solar photo-voltaic water pumping systems: Case of Abakore borehole water supply system in Kenya

Abstract

A solar photovoltaic (PV) water pumping system was investigated to determine performance and economic viability. An in-built data logger was used to collect real time data on key performance parameters. Performance indicators were defined and determined, while economic viability was analyzed using life-cycle cost (LCC) method and these costs were compared with a diesel generator pumping system. Solar irradiance varied from 63 W/m 2 to a peak of 857 W/m 2 , corresponding to a maximum power output of 11.75 kW. PV array efficiency of 12.1%, subsystem efficiency of 91.82% and overall efficiency of 5.14% were obtained, which are well comparable to the efficiencies reported elsewhere for similar systems. The LCC analysis showed a 20 year average unit water cost of 0.25 US $/m 3 for solar PV system and 0.6 US $/m 3 for diesel genset system. Solar PV system is found to be more cost effective and suitable for use over conventional sources.