Smart Solar Drip Irrigation System for Reducing Operational Carbon Emissions and Enhancing Water-Use Efficiency under Egyptian Agricultural Conditions

Abstract

Water scarcity, irrigation energy demand, and greenhouse gas emissions are the major constraints to sustainable agricultural production in arid regions. This paper proposes an integrated Smart Solar Drip Irrigation System (SSDIS), which is comprised of photovoltaic (PV) power generation, low-pressure drip irrigation, Internet of Things (IoT)-based soil-moisture sensing, automated irrigation control, and remote monitoring. For a typical one-acre tomato field, we performed hydraulic and photovoltaic design calculations and built a laboratory-scale prototype to test the sensing and control functions. The design procedure was to estimate crop water demand, irrigation flow rate, pipe sizing, total dynamic head, pump selection, and PV array sizing, followed by Energy, Exergy, Economic, and Environmental (4E) assessment. The estimated irrigation-water requirement was 30 m³/day, which was equivalent to a design flow rate of 5 m³/h for six hours of daily pumping. Hydraulic analysis gave a total dynamic head of 60 m, and a 1.5 kW submersible pump was selected. The final installed PV array capacity was 2.2 kWp, comprising four 550 W modules. The exergy efficiency was found to be about 8.5%. The estimated annual economic saving and simple payback period were 18600 EGP/year and 4.5 years, respectively. Prototype observations suggested that soil-moisture-based control reduced unnecessary irrigation events and allowed for demand-based water application. Prototype monitoring also indicated lower water delivery under the controlled drip-irrigation configuration than under the adopted flood-irrigation baseline. Because photovoltaic pumping does not require diesel combustion during normal operation, the proposed configuration also avoids direct fuel-combustion emissions at the point of use.