Solar Dish-Stirling Pump for Irrigation: Site Suitability and Performance Assessment

The growing global population has intensified demand for water, food, and energy, straining fossil fuel reserves and accelerating climate change. Water scarcity, especially in developing countries, hinders sustainable development. Enhancing agricultural productivity through modern irrigation technologies is essential to reducing rain-fed dependence and ensuring food security. Solar energy offers a sustainable alternative for irrigation. This study evaluates a solar dish concentrator integrated with a Stirling engine- driven pump and conical cavity receiver. The system, featuring a 2.8 m aperture diameter and 0.4 m depth concentrator, was assessed across four Ethiopian sites (Ziway, Dangila, Itang, and Jigjiga) based on solar radiation, groundwater potential, and irrigation demand. Using a weighted matrix method, Ziway was identified as the most suitable site for detailed analysis. COMSOL Multiphysics simulation showed an average receiver surface temperature of 574 K. Results indicate that solar radiation variations significantly affect thermal output, dish efficiency, and flow rate. Under optimal conditions, concentrator and Stirling engine efficiencies reached 83.69% and 39.01%, with overall energy and exergy efficiencies of 23.38% and 25.07%. The system produced 132 W peak power and 24,240 L/day flow, confirming potential for sustainable irrigation and rural development.