Cao, J., Dong, J., Wu, J., & Suwardi, A. (2025). Evapolectrics: Direct Harvesting of Electricity from Evaporation Using Thermoelectrics. ACS Nano, 19(28), 26249–26258. https://doi.org/10.1021/acsnano.5c10693
Abstract:
Evaporation, a ubiquitous process driving Earth’s water–energy cycle, has been largely untapped for energy harvesting. Here, we introduce “evapolectrics,” a scalable strategy that directly converts evaporation enthalpy into electricity via thermoelectric generators (TEGs). By leveraging porous graphite coatings and optimizing wind speeds (2.8 m/s) and wet-bulb depression, a robust temperature gradient (ΔT) over 6 °C can be maintained across TEGs. This translates to a power density of 4.2 W/m2, which exceeds other ambient energy harvesting technologies, such as triboelectric and hydrovoltaics. We also demonstrate the evapolectrics’ ability to sustain a continuous power output of 2.72 mW over 30 min and scalability via a 7 × 7 device array. Unlike intermittent sources like solar or wind, evaporation’s perennial nature offers reliable ambient energy harvesting. With global evaporation rates suggesting harvestable energy of ∼105 TJ/year, evapotetics present a transformative approach to power self-sustaining devices, augmented by advances in thermoelectric materials.
License type:
Attribution 4.0 International (CC BY 4.0)
Funding Info:
This research / project is supported by the A*STAR - e-Asia Joint Research Program
Grant Reference no. : R22I1IR053
This research / project is supported by the National Research Foundation - LCER Phase 2 Emerging Technology Grant Call (ETGC)
Grant Reference no. : U2411D4011