Hybrid Life Cycle Assessment of a Nano-Enhanced Phase Change Material (NEPCM) Integrated Double-Effect Single-Slope Solar Still in Nigeria

Increasing demand for freshwater and the need to reduce the carbon intensity of conventional desalination have accelerated interest in solar-driven distillation technologies. This study performs a cradle-to-grave Life-Cycle Assessment (LCA) of a nano-enhanced, double-effect single-slope Solar Still fabricated in Nigeria to quantify its embodied environmental impacts and identify material-level hotspots. Modeling was conducted in openLCA v2.4.1 using the Australian Life-Cycle Inventory (2019) database as a proxy. The functional unit was defined as the production of 1 m3 of freshwater distillate over a ten-year operational lifetime. From the analysis, the total Global Warming Potential (GWP100) of the fabricated Solar Still was 337.3 kg CO2-eq, which corresponds to a normalized carbon intensity of 25.21 kg CO2-eq m−3 for a lifetime yield of 13.38 m3. Contribution analysis revealed that Al2O3 nanoparticles (31.5%), paraffin wax PCM (22%), and galvanized steel (19%) and glass (13%) together account for more than 85% of total embodied emissions, confirming that the Solar-Still’s footprint is materials-dominated. When benchmarked against conventional desalination, the system’s carbon intensity lies above reverse osmosis but within the upper range of multi-stage flash distillation, with the advantage of zero operational emissions. Sensitivity analyses were performed to examine the influence of nano-enhanced PCM content, alumina concentration, and system lifespan on overall impacts. The novelty of this study lies in the hybrid-LCI approach adopted to provide a replicable framework for evaluating nanomaterial-enhanced renewable-energy systems in emerging regions. Key opportunities for improvement through bio-based or recyclable PCMs, low-impact nanomaterial synthesis, and design optimization to enhance productivity and material circularity were also highlighted in the study.