This research develops and evaluates sustainable freshwater recovery systems based on humidification&ndashdehumidification (HDH) using renewable energy. Three approaches were explored: (a) a geothermal wastewater recovery system, (b) a solar-powered seawater/wastewater desalination system with evacuated tube heat pipe/U-tube collectors, and (c) a U-tube collector-based humidification-condensation system. The geothermal system, validated against literature with ±8% error, showed hot spring temperature as the key performance factor. Feasibility mapping identified composite climates as most suitable, achieving up to 0.78 L/h water recovery. The solar desalination system, validated experimentally (±12% error), revealed that collector exit temperature strongly affects energy exchanges (0.91 kW/m² in humidifier, 0.21 kW/m² in condenser) and freshwater rate (0.154 L/h·m²). Optimization of condenser effectiveness and flow ratios further enhanced output. The U-tube collector-based system, modeled using finite difference (R² > 0.98), achieved up to 1.445 L/h·m² water extraction and 1.37 kW/m² condenser energy exchange, with air inlet temperature and humidity ratio as critical parameters. Experimental HDH studies with SS304 mesh and Celdek 7090 packing showed higher water yield (0.825 kg/h), energy efficiency (35.6%), and GOR (0.65) using structured packing, though with higher pressure drop. Exergy analysis revealed humidifier irreversibility (>85%). Response Surface Methodology (R² > 0.99) validated optimization. Overall, geothermal and solar-driven HDH systems prove to be viable, eco-friendly solutions for decentralized freshwater production, offering key insights into design, optimization, and implementation across diverse climates.