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Photovoltaic panel cooling by atmospheric water sorption–evaporation cycle


More than 600 GW of photovoltaic panels are currently installed worldwide, with the predicted total capacity increasing very rapidly every year. One essential issue in photovoltaic conversion is the massive heat generation of photovoltaic panels under sunlight, which represents 75–96% of the total absorbed solar energy and thus greatly increases the temperature and decreases the energy efficiency and lifetime of photovoltaic panels. In this report we demonstrate a new and versatile photovoltaic panel cooling strategy that employs a sorption-based atmospheric water harvester as an effective cooling component. The atmospheric water harvester photovoltaic cooling system provides an average cooling power of 295 W m2 and lowers the temperature of a photovoltaic panel by at least 10 °C under 1.0 kW m2 solar irradiation in laboratory conditions. It delivered a 13–19% increase in electricity generation in a commercial photovoltaic panel in outdoor field tests conducted in the winter and summer in Saudi Arabia. The atmospheric water harvester based photovoltaic panel cooling strategy has little geographical constraint in terms of its application and has the potential to improve the electricity production of existing and future photovoltaic plants, which can be directly translated into less CO2 emission or less land occupation by photovoltaic panels. As solar power is taking centre stage in the global fight against climate change, atmospheric water harvester based cooling represents an important step toward sustainability.

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Fig. 1: Schematic of the hydrogel synthesis process and the two operation modes.
Fig. 2: Characterization of the PAM-CNT-CaCl2 hydrogel.
Fig. 3: Cooling performance of the PAM-CNT-CaCl2 hydrogel cooling layer.
Fig. 4: Parallel comparison of PV panel characteristics with and without the cooling layer attached.
Fig. 5: Cooling performance of the PAM-CNT-CaCl2 hydrogel under simulated sunlight irradiation.
Fig. 6: Cooling performance of the PAM-CNT-CaCl2 hydrogel under water collection mode.

Data availability

The data that support the findings of this study are available from the corresponding author on reasonable request.


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This work was supported by the King Abdullah University of Science and Technology (KAUST) Center Competitive Fund (CCF), awarded to the Water Desalination and Reuse Center (WDRC).

Author information




P.W. supervised the project; R.L., Y.S. and P.W. conceived the idea and designed the experiments; R.L. and M.W. conducted the materials synthesis, characterization and performance investigation; S.H. produced the graphics; R.L. and P.W. co-wrote the paper. All the authors discussed and commented on the manuscript.

Corresponding author

Correspondence to Peng Wang.

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Competing interests

P.W., R.L. and Y.S. have a patent application related to the work presented in this paper (U.S. Application No. 62/767,646).

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Supplementary Information

Supplementary Figs. 1–18, Notes 1–3 and Tables 1–3.

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Li, R., Shi, Y., Wu, M. et al. Photovoltaic panel cooling by atmospheric water sorption–evaporation cycle. Nat Sustain 3, 636–643 (2020).

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