Water-Energy Nexus for Global Sustainability: A Comprehensive Review, Challenges, Innovations, and Strategic Solutions

The Water-Energy Nexus (WEN) represents the critical interdependence between water and energy systems (WES), where energy is used to power water extraction, treatment, and distribution. In contrast, water is equally vital for energy generation, industrial processes, and sustaining power production infrastructure. Rapid population growth, urbanization, climate change, and escalating energy demands are intensifying pressure on both resources, posing significant sustainability challenges worldwide. Understanding and addressing the WEN has, therefore, become critical for achieving long-term environmental, social, and economic resilience. This paper presents a comprehensive review of the literature published between 2010 and 2024, synthesizing key technological innovations, policy frameworks, and global case studies that address the complex interlinkages of WEN. The findings reveal persistent gaps, including fragmented governance structures, inconsistent adoption of nexus-based models across regions, limited integration of renewable energy sources, and the absence of a universally accepted framework for implementing WEN strategies. The study highlights the increasing importance of integrating renewable energy into water infrastructure, the adoption of innovative water systems facilitated by digital technologies, and the utilization of data-driven decision-making tools, such as artificial intelligence and predictive analytics, to enhance operational efficiency and resilience. Furthermore, it emphasizes the need for harmonized policy development, robust cross-sector collaboration, and improved institutional frameworks to facilitate coordinated action across the WEN sector. Expanding research on feedback mechanisms between WES is crucial to optimizing resource use and supporting the achievement of the United Nations Sustainable Development Goals (SDGs). This review offers actionable recommendations to promote sustainable and resilient WEN solutions worldwide.