Identification of Best Methodologies for Solar Desalination Enhancement: A Systematic Literature-Based Review of Paraffin Wax Phase Change Materials Integrated with Wood Waste Nanomaterials

Solar desalination is a renewable alternative to energy-intensive desalination methods, particularly in the context of water scarcity exacerbated by climate change, industrial expansion, and population growth. However, conventional solar stills suffer from limitations like intermittent solar input and poor heat retention capacity. This paper not only summarizes the earlier findings but also attempts to find out, compare and rank the methodologies which the researchers have used for improving the performance of solar stills by incorporating the phase change material (PCM), especially the paraffin wax and its nano-enhancement using metallic and wood-waste-derived nanomaterials, respectively. A structured criteria-based literature evaluation framework is proposed, which evaluates published methodologies against productivity gain, thermal conductivity improvement, cost, environmental impact and long-term operational stability. The paper identifies experimental and nano-material-selection methodologies that have the best combination of performance and sustainability from this comparative evaluation and proposes a methodological roadmap for future experimental validation of wood-waste-based nano-PCM solar stills. The findings are intended to help researchers choose rigorous, reproducible and sustainable methods for future solar desalination research.