Sustainable water purification for off-grid communities using integrated solar technologies

This study examines the performance of an integrated solar-powered water purification system developed for rural and off-grid use. The main objective was to develop a cost-effective and efficient purification device that integrates photovoltaic (PV) and solar thermal energy technologies. The analysis focused on the heat-transfer and overall efficiency of both a conventional solar still and an upgraded integrated system. Dual immersion heaters, each rated at 150 W, were used to support the evaporation stage, while the basin was insulated with layered foam padding, newspaper, and cardboard. This arrangement provided an overall thermal conductivity of about 0.067 W/(m·K), helping to minimize heat loss during operation. Experimental findings showed that the conventional still operated at an efficiency of 26.65 %, and the corrugated version reached 29.61 %. When powered by the integrated PV–thermal setup, the water purification unit achieved a substantially higher efficiency of 50.26 %. The improved design produced an average of 7 liters of clean water per day, compared with only 1.8 liters from the conventional configuration. Water samples from each treatment stage met WHO drinking-water criteria. Economic assessment further indicated that the integrated system offered a shorter payback period of 0.61 years, confirming its suitability for deployment in remote, low-income regions.