Performance assessment of a solar hybrid potable atmospheric water generator using vapour adsorption-thermo electric cooling system

Abstract

Water scarcity remains a critical global challenge, threatening sustainable development and demanding innovative solutions. While desalination is widely regarded as a popular method to address this issue, its energy-intensive nature, production of non-potable byproducts, high cost, and bulky infrastructure make it less suitable for widespread adoption. An alternative approach is the atmospheric water generation system, for which the most commonly used method is the vapour compression systems. However, these systems have their drawbacks, including high energy consumption, reduced effectiveness in low-humidity environments, environmental concerns from refrigerants, and significant maintenance costs. To overcome these limitations, the vapour adsorption system emerges as a promising alternative. It is energy-efficient, environmentally friendly with non-toxic adsorbents, capable of operating in low-humidity conditions, and compatible with renewable energy sources like solar power. However, the system’s relatively low water production rate underscores the need for a hybrid approach to improve both efficiency and output. This consideration has led to the integration of adsorption cooling systems with thermoelectric cooling for atmospheric water generation. Therefore, this study aims to introduce and evaluate a hybrid vapour adsorption–thermoelectric cooling system designed to enhance potable water production. The study is structured in three phases. In the first phase the thermodynamic modelling based on the first law of thermodynamics is conducted. The investigate is to determine the effect of ambient temperature, relative humidity, current, fin length, on the performance of the system. The MATLAB R2024a platform is used for the modelling of the system. The modelling results indicates a maximum output of 71 mL.h⁻¹ for thermoelectric cooling and 121 mL.h⁻¹ for vapour adsorption cooling system at 95 % relative humidity. The design fabrication and performance investigation of the hybrid system is conducted in the second phase. The experimental results confirm a water output of 80.8 mL.h⁻¹, with thermo-electric cooling system contributing 18 mL.h⁻¹ and vapour adsorption cooling system 62.8 mL.h⁻¹ at 30 °C and 75 % relative humidity. In the third phase the economic analysis of the hybrid system is conducted. The hybrid system achieves a daily water output of 1.18 L.day⁻¹, with generation costs estimated at 0.33 $ per litre. The hybrid configuration outperforms standalone systems, offering improved scalability and operational efficiency. An economic analysis highlights its viability and potential as a sustainable solution to address global water scarcity challenges.