Bridging solar harvesting technologies using hydrogels towards sustainability

The utilization of solar energy has been integral to biological evolution, industrial revolution, and humanity's journey across the past, present, and future, shaping both natural ecosystems and technological advancements. Effectively harnessing this sustainable energy is crucial for addressing the escalating and coupled global energy-water-environment crises. This tutorial review advances an integration paradigm in which hydrogels serve as adaptable and scalable matrices enabling cost-effective solar harvesting that aligns with sustainability and economic feasibility. We first summarize the challenges inherent in existing solar technologies and extrinsic factors beyond material design that influence their sustainable development. Next, we highlight the transformative potential of integrating hydrogels into advanced solar systems through hierarchical energy utilization, multifunctional coordination, and enhanced environmental adaptability and stability. Finally, we assess the broader technological and societal implications of integrated solar harvesting systems by considering regional economic disparities, local resource availability, societal needs, and environmental impacts. By offering a pragmatic perspective on hybrid solar technologies, this tutorial review bridges academic innovation and practical application, charting pathways toward high-efficiency, cost-effective solar energy utilization, with hydrogels serving as a versatile integration platform. These advancements not only foster sustainable development but also contribute to aquatic and terrestrial ecosystem resilience while driving progress toward more resilient, eco-friendly societies.