Transient modeling and performance analysis of a hybrid SS–HDH desalination system for remote areas

This paper presents the transient modeling of a novel solar desalination system designed for remote areas with low freshwater demand. The proposed system integrates a solar still (SS) with a multi-effect Humidification-Dehumidification (HDH) unit and a built-in solar absorber. The objective is to model and optimize an integrated SS-HDH-absorber configuration capable of delivering 50 L of freshwater per day, suitable for single-family use. A numerical model was developed in MATLAB to simulate the coupled thermal and mass transfer processes and evaluate the impact of environmental and operational parameters. Simulations were performed under forced air circulation, using solar and weather data representative of the United Arab Emirates (UAE). The system achieved the target of 50 L/day freshwater production in both summer and winter scenarios. In winter, the basin contributed 6.3 kg/m 2 /day, while the dehumidifier produced 13 kg/day. In summer, productivity increased to 8.5 kg/m 2 /day from the basin and 16.6 kg/day from the dehumidifier. The integrated system is compatible with Zero Brine Discharge (ZBD) strategies by allowing passive salt concentration and in-situ crystallization within the basin. While not fully validated here, this lays the foundation for a future low-maintenance, brine-free desalination approach suitable for decentralized communities.