Development and Performance Evaluation of a Timer-Controlled Solar- Powered Drip Irrigation System for Smallholder Farmers

This study developed and evaluated a timer-controlled solar-powered drip irrigation system for smallholder farming. The system used an ESP32 microcontroller and DS3231 real-time clock to schedule irrigation across a 70-day cucumber growth cycle. Hydraulic performance was assessed using coefficient of uniformity (CU), emission uniformity (EU), coefficient of variation (CV) and flow variation (FV). Timer performance was evaluated across four growth stages by comparing actual and programmed irrigation durations. The power subsystem comprised a 50 W PV module, a 10 A/12 V PWM charge controller and a 12 V, 70 Ah lead-acid battery. It was estimated to generate 168.75 Wh/day against an adjusted demand of 100.9 Wh/day, providing about 4.16 days of autonomy at 50% depth of discharge. The pump drew 83.2 W (≈6.93 A at 12 V), and PV output was projected to meet demand at 2.69 peak sun hours/day, below which the battery supplied the deficit. The system achieved CU and EU of 96.74% and 95%, indicating high water-distribution uniformity. CV was 3.96% and FV was 14.63%. Timer errors ranged from −0.94% to +2.68%, with the largest error during the 41-minute mid-season schedule. Analysis of variance showed significant differences in timer error among growth stages (F = 80.86, p < 0.001). These findings demonstrate favourable hydraulic uniformity, timing performance and nominal power-subsystem adequacy. However, crop-yield improvement, water savings and long-term solar reliability were not independently established. Further field evaluation, including solar-energy performance, irrigation-water application and crop response, is recommended before wider deployment