Solar-Powered Integrated Thermoelectric System for Simultaneous Electricity and Freshwater Production With Salt and Brine Recovery

Abstract

The global crises of water and energy scarcity call for integrated technologies that transcend single-function operation. Here, we present a solar-powered integrated thermoelectric generator (SPI-TEG) that relies solely on sunlight to synergistically co-produce electricity, freshwater, concentrated brine, and solid salt within a single device. The SPI-TEG employs a wavelength-selective absorber at the hot side of a thermoelectric module to maximize solar-to-heat conversion, while a superhydrophilic cleanroom wiper placed at the cold side enables continuous seawater transport and efficient evaporative cooling. This configuration establishes a significant temperature difference for power generation and simultaneously reutilizes the dissipated heat for desalination. Under 1.0 sun illumination, the device achieves a notable open-circuit voltage of 258.8 mV, a power density of 0.504 W m⁻², and an evaporation rate of 1.79 kg m⁻² h⁻¹, with a freshwater collection rate of 0.632 kg m⁻² h⁻¹. Notably, through circulating evaporation, the device enables tunable brine concentration and achieves zero liquid discharge with a salt recovery rate of up to 83%. This work offers a practical zero-carbon route for synergistic water-electricity cogeneration and sustainable ocean resource recovery.