Water stress-renewable energy nexus for green hydrogen: A spatial assessment framework in Türkiye

Climate change and rising energy demand are intensifying freshwater scarcity, highlighting the need for sustainable energy. Green hydrogen production and utilization hold significant potential for reducing greenhouse gas emissions, enhancing energy security, promoting economic growth, and decarbonizing sectoral emissions. Given that renewable energy and water resources constitute the fundamental inputs of green hydrogen production, ensuring environmental and spatial sustainability has become an essential requirement. This study aims to propose a spatial assessment framework to ensure sustainability in green hydrogen production with respect to water and renewable energy resources. In line with Türkiye’s international climate commitments and national energy transition targets, a spatial evaluation framework is developed based on water and solar-wind energy indicators under different climate scenarios for the projection years 2030 and 2050. Spatial assessments are conducted using parameters of water stress, solar irradiation, photovoltaic power potential, wind speed, and wind power density. Within the integration of geographic information systems and fuzzy logic, a criteria-based spatial assessment is developed in ArcGIS Pro using fuzzy linear membership functions and the fuzzy GAMMA operator (𝛾 = 0.90). The results reveal that the coastal zones of Southern Marmara, the Mediterranean, and the Aegean regions exhibit high solar-wind renewable energy potential while simultaneously experiencing very high levels of water stress. The coastal location of these regions, where both renewable energy potential and water stress are high, indicates that seawater-based rather than freshwater-based planning may offer a more sustainable pathway for the spatial and environmental sustainability of green hydrogen. The study highlights that seawater-based green hydrogen production can provide significant spatial and environmental contributions to the decarbonization process under increasing present and future water stress, providing an evidence-based spatial decision-support framework for water-stressed countries.