Exergy-Based Evaluation of Renewable Energy Integration in Onion Production Systems

Abstract

Modern agricultural systems heavily rely on carbon-intensive energy inputs, emphasizing the urgent need to assess and optimize specific crop supply chains from thermodynamic and environmental perspectives. This study presents a comprehensive cumulative assessment of the energy, exergy, and carbon emissions of onion production in Türkiye, utilizing mass, energy, and entropy balance formulations combined with field-survey data from Adıyaman province. The results indicate that the total cumulative energy consumption is 722.28 MJ/ton, with nitrogen fertilizer contributing 61%. The thermodynamic analysis reveals that nitrogen fertilizer, irrigation water, and diesel fuel drive a cumulative exergy consumption of 465.83 MJ/ton, while irrigation water dominates the carbon emission at 20.65 kg CO2/ton. Based on these streams, integrated sustainability indicators specifically the Cumulative Degree of Perfection (CDP) and the Renewability Index (RI) were calculated under conventional and solar modernization scenarios. A renewable energy scenario incorporating photovoltaic-powered irrigation and electrified machinery substantially enhanced thermodynamic perfection and process renewability, increasing CDP from 3.33 to 6.22 and RI from 0.70 to 0.84. These findings offer actionable insights for scaling local solar-driven modernization to mitigate grid dependency and support global Sustainable Development Goals (SDGs) by reducing fossil-fuel integration.