A comparative analysis of the role of carbon dioxide in multi-slope solar stills

The minimisation of carbon dioxide (CO₂) footprint is a significant problem for freshwater production. Freshwater produced by sunlight is a renewable energy that helps to reduce CO₂ emissions. The aim of this research is to investigate the CO₂ footprint of solar stills. The embodied energy analysis is used to determine the CO₂ footprint, as well as CO₂ mitigation, carbon credit energy generation factor and life cycle conversion efficiency (LCCE). The comparison is made on a single basin multi-slope solar still. The multi-slope is a square-shaped pyramid that acts as a transparent medium in the solar still. Two multi-slope solar stills were built for experimental purposes. In multi-slope solar stills, two types of experiments are performed to measure the CO₂ emission footprint and energy consumption: without shading and with shade on a glass plate. The findings of the analyses reveal that CO₂ emissions’ footprint and embodied energy were lower in CPS than in SPS, while CO₂ mitigation, carbon credit, energy production factor and LCCE were higher in CPS. In addition to the analysis, the footprint of CO₂ emissions from the single-slope still shading (SSSS) and multi-slope still shading (SSSS) were compared.