DEVELOPMENT OF AN IMPROVED LOW-COST SOLAR STILL FOR THE PRODUCTION OF POTABLE WATER FOR REGIONS WITH LOW SOLAR IRRADIANCE

Many developing countries are faced with inadequate access to potable water, especially in rural and peri-urban areas, where available freshwater is unsuitable for domestic use. Desalination is a potential solution for purifying polluted or saline water, but common methods are energy-intensive, driving interest in more economical options like solar distillation. Solar distillation, which uses a solar still for water purification, is a promising method but is often limited by low productivity. Single-basin solar stills typically achieve less than 5 litres of freshwater per square meter per day, necessitating further research to enhance output. The primary objective of this study was to develop a cost-effective solar still by incorporating paraffin wax as a phase change material coupled with a heating element (soleplate of a solar pressing iron) to boost productivity. Findings showed that productivity increased with the mass of paraffin wax, reaching a maximum value of 8.6 liters per square meter. Productivities were recorded as 0.75 litres per square meter for the passive solar still, 4.2 litres per square meter for the active solar still, and a peak of 8.6 litres per square meter for the enhanced solar still, reflecting a 104.8% increase in productivity. With a basin water volume of 3 litres, the conventional solar still reached a maximum temperature of 41.2°C, while the enhanced solar still achieved 89.6°C. The cost of water production from the solar still was estimated at $0.01 per litre.