Economic viability of crop-specific solar irrigation designs under diverse agricultural management and grid-connected conditions: Insights from Qazvin Plain, Iran

The depletion of fossil fuels as the primary energy source and the associated environmental impacts contradicts sustainable development goals. A viable global solution involves harnessing renewable solar energy. With growing emphasis on pressurized irrigation systems in water-intensive agriculture and their significant energy demands, solar-powered irrigation has emerged as a promising alternative. However, financial viability remains a key challenge. This study examines solar irrigation systems tailored to the Qazvin Plain, Iran, focusing on fixed rain and strip sprinklers across three cultivated area scales for two crops—fodder corn and wheat—under single-season and double-season scenarios. Results highlight the critical role of crop type, cultivation scale, and irrigation methods in economic feasibility. Optimal system design prioritizing minimal energy use is essential, considering each agricultural plot's specific attributes. Notably, surplus electricity sales to the national grid could generate income 35–45 times the initial cost over 20 years for single-season plans and 31–38 times for double-season plans, with the initial investment recouped within six years. The net present value in all scenarios confirms the financial rationale for adopting solar irrigation systems, underscoring their potential to align agricultural practices with sustainability and economic efficiency.