MATLAB-Based Numerical Performance Analysis of an Innovative HDH Desalination System with Active Thermoelectric Condensation for Decentralized Water Production

Freshwater scarcity remains a major challenge across many African regions, particularly in remote and arid areas where access to centralized water infrastructure and reliable energy resources is limited. In this context, humidification–dehumidification (HDH) desalination represents a promising decentralized solution for sustainable freshwater production due to its low operating temperature, simple design, and compatibility with renewable energy systems. However, the efficiency of conventional HDH systems is often constrained by passive condensation processes that are highly sensitive to ambient climatic conditions. This study presents a numerical investigation of an innovative HDH desalination system integrating active thermoelectric condensation using Peltier cooling modules. The proposed system operates in a closed-loop water circulation, open-air configuration and incorporates dual evaporators and a coaxial air–water heat exchanger to improve heat recovery and thermal efficiency. The system is designed to be powered by solar photovoltaic energy, making it suitable for decentralized and off-grid applications in water-stressed regions. A comprehensive numerical model was developed using MATLAB to simulate the system performance under various climatic conditions. Simulation results demonstrate that the active condenser significantly improves freshwater productivity compared to conventional passive configurations. Under hot and dry climatic conditions (38 °C and 45% relative humidity), the system achieved a maximum freshwater production corresponding to a 57% improvement compared to a conventional single-evaporator HDH system and a 22% increase relative to a passive-condenser configuration with heat recovery. In addition, the thermoelectric condenser maintained stable condensation performance under highly humid conditions, ensuring improved operational reliability and resource efficiency. The findings highlight the potential of combining renewable energy, heat recovery, and active thermoelectric cooling to develop sustainable and energy-efficient desalination technologies adapted to African environmental conditions. The proposed system contributes to decentralized water production, environmental sustainability, and the strengthening of climate-resilient water solutions for vulnerable communities.