Solar Water Pumping System Design for Smallholder Irrigation in Sokoto State

This project designs a standalone solar photovoltaic water pumping system for smallholder agricultural irrigation in Sokoto State, North West Nigeria, where abundant solar irradiation and water scarcity combine to create a strong case for PV-powered groundwater extraction. Smallholder farmers in Sokoto face high diesel fuel costs and unreliable grid supply, limiting their access to affordable irrigation and constraining crop yields during the dry season. The system design incorporates a polycrystalline PV array, a variable frequency drive, a three-phase submersible pump, and a water storage tank. The variable frequency drive enables soft-starting of the pump motor and matches motor speed to available solar power, eliminating the need for battery storage and reducing system cost. System sizing was based on the daily water requirement of one hectare of irrigated land and the average daily solar irradiance data for Sokoto, which exceeds 5.8 peak sun hours. Hydraulic analysis determined pump head requirements based on the aquifer depth and pipe losses of the targeted installation site. A MATLAB simulation was used to model system performance across seasonal irradiance variations. Results indicate that the system can pump an average of 38,000 litres per day during peak irradiance months, meeting the full irrigation demand. Cost comparison against diesel pumping shows a payback period of approximately 2.8 years. The project recommends community-shared ownership models to reduce per-farmer capital outlay and improve system maintenance. Keywords: solar water pump, photovoltaic, irrigation, variable frequency drive, Sokoto State.