Browser tab content: # Photovoltaic-sorbent system for water and electricity generation

## Abstract

[![Graphical abstract undfig2](https://www.cell.com/cms/10.1016/j.joule.2024.01.006/asset/ea0d24c7-300d-4c0d-b810-3232fc6d0cda/main.assets/fx2.jpg)](https://www.cell.com/cms/10.1016/j.joule.2024.01.006/asset/c7efbcf5-73ae-4ad4-bb57-3bc0194cb286/main.assets/fx2_lrg.jpg "View full size image in a new tab")

Zhao Shao is a PhD candidate at the School of Mechanical Engineering, Shanghai Jiao Tong University. His research focuses on the solar energy utilization, efficient dehumidification, atmospheric water harvesting (AWH), and analysis of carbon neutrality strategy. He has conducted a series of solar-based AWH systems and assessment models of carbon emission reduction. His research has been published in top journals such as _Device_, _Applied Physics Reviews_, _Energy_, and _Engineering_. He was awarded the 1st prize in the IIR Best Student Paper Competition at the 26th International Congress of Refrigeration (Paris, Aug. 2023).

[![Graphical abstract undfig3](https://www.cell.com/cms/10.1016/j.joule.2024.01.006/asset/2ef97fa0-48d3-4714-b661-e7ef83a853ec/main.assets/fx3.jpg)](https://www.cell.com/cms/10.1016/j.joule.2024.01.006/asset/9dd2d204-2cda-43b2-a284-e9762c254721/main.assets/fx3_lrg.jpg "View full size image in a new tab")

Primož Poredoš is an Assistant Professor in the Faculty of Mechanical Engineering, University of Ljubljana. From 2021 to 2023, he was a postdoc fellow at Shanghai Jiao Tong University under the leadership of Prof. Ruzhu Wang. He participated in research on seawater desalination as part of the Belt and Road project as a member of the research group of Prof. Ruzhu Wang. His research interests include continuous atmospheric water harvesting using sorbent and radiative sky cooling materials, particularly emphasizing the utilization of radiative sky cooling materials and waste heat for various applications within the energy-water-air nexus.

[![Graphical abstract undfig4](https://www.cell.com/cms/10.1016/j.joule.2024.01.006/asset/bb547ae0-df13-43c3-a729-5c42992c5b8e/main.assets/fx4.jpg)](https://www.cell.com/cms/10.1016/j.joule.2024.01.006/asset/a333682e-962d-4282-8f66-79d0bf035804/main.assets/fx4_lrg.jpg "View full size image in a new tab")

Dr. Ruzhu Wang, born in Dec., 1964, is a chair professor of Shanghai Jiao Tong University and Director of the Institute of Refrigeration and Cryogenics. He has published 12 books, over 700 co-authored international journal papers, and more than 150 patents. He is a well-known, world-leading scientist in refrigeration, heat pump, and energy-water-air nexus. His achievements have won Chinese National Research Awards in 2010 and 2014, and he has received seven prestigious international academic awards, including the IIR-Gustav Lorentzen Medal from the International Institute of Refrigeration and the Peter Ritter von Rittinger International Heat Pump Award from the International Energy Agency. Prof. Wang is the laureate of the 2023 Global Energy Prize.

## Graphical abstract

[![Graphical abstract undfig1](https://www.cell.com/cms/10.1016/j.joule.2024.01.006/asset/716d4061-221d-4cc1-ae82-306825136b96/main.assets/fx1.jpg)](https://www.cell.com/cms/10.1016/j.joule.2024.01.006/asset/5b9e83eb-0196-40a3-ac89-b1699e641204/main.assets/fx1_lrg.jpg "View full size image in a new tab")

## Main text

### Introduction

Photovoltaic (PV) systems, which convert inexhaustible solar energy into renewable electricity, are expected to play a leading role in the development of the energy system. Globally, these systems generated 1002.9 TWh of electricity in 2021, as indicated by historical data and predictions under the _Net Zero Scenario_ by the IEA (shown in [Figure 1](#fig1)).[1](#),[2](#)

2.

Chang, N.L. ∙ Dehghanimadvar, M. ∙ Egan, R.

**The cost of risk mitigation—Diversifying the global solar PV supply chain**

_Joule._

2022; **6**:2686-2688

This growing trend will continue, and renewable energy will take up a growing share of electricity generation, requiring more effort to increase the efficiency of PV cells. During the energy conversion process of a common solar PV, most solar energy is converted into heat (usually ∼80%[3](#)

3.

van Helden, W.G.J. ∙ van Zolingen, R.J.C. ∙ Zondag, H.A.

**PV thermal systems: PV panels supplying renewable electricity and heat**

_Progress in Photovoltaics._

2004; **12**:415-426

), and the thermal power per square meter can exceed 600 W.[4](#)

4.

Yao, J. ∙ Dou, P. ∙ Zheng, S. ...

**Co-generation ability investigation of the novel structured PVT heat pump system and its effect on the “Carbon neutral” strategy of Shanghai**

_Energy._

2022; **239**, 121863

Obviously, this can cause an inevitable temperature increase of the solar cells, thereby reducing their power generation efficiency. To develop high-efficiency solar cells, increasing the power conversion efficiency of cells with temperature coefficients ranging from 0.24% K−1 to 0.45% K−1,[5](#)

5.

Kettle, J. ∙ Aghaei, M. ∙ Ahmad, S. ...

**Review of technology specific degradation in crystalline silicon, cadmium telluride, copper indium gallium selenide, dye sensitised, organic and perovskite solar cells in photovoltaic modules: Understanding how reliability improvements in mature technologies can enhance emerging technologies**

_Prog. Photovolt._

2022; **30**:1365-1392

enhancing the dissipated heat for solar cells may be a potential pathway. Current cooling technologies for PV cells mainly rely on active cooling using cold water or airflow. However, such active methods require extra energy input and may be limited in off-grid scenarios.

[![](https://www.cell.com/cms/10.1016/j.joule.2024.01.006/asset/4cc8009c-76f3-44e5-8611-d79464f918e3/main.assets/gr1.jpg)](https://www.cell.com/cms/10.1016/j.joule.2024.01.006/asset/4c9bf8d7-95f9-4ae9-bbf9-957ba10b1cd8/main.assets/gr1_lrg.jpg "View full size image in a new tab")

Figure 1 Power generation data and prediction

Recently, researchers found that solar PV modules can be cooled in a completely passive way by sorbent-based evaporative cooling (SBEC).[6](#)

6.

Li, Z. ∙ Ma, T. ∙ Ji, F. ...

**A Hygroscopic Composite Backplate Enabling Passive Cooling of Photovoltaic Panels**

_ACS Energy Lett._

2023; **8**:1921-1928

,[7](#)

7.

Li, R. ∙ Wu, M. ∙ Aleid, S. ...

**An integrated solar-driven system produces electricity with fresh water and crops in arid regions**

_Cell Reports Physical Science._

2022; **3**, 100781

,[8](#)

8.

Li, R. ∙ Shi, Y. ∙ Wu, M. ...

**Photovoltaic panel cooling by atmospheric water sorption–evaporation cycle**

_Nat. Sustain._

2020; **3**:636-643

This technology path can be applied not only to future PV component manufacturing but also to upgrade existing deployed PVs by simply retrofitting SBEC components. Compared to natural convection cooling, SBEC can help solar PV cells achieve lower temperatures, andthe released water vapor can be regarded as a new source for freshwater generation.[9](#)

9.

Poredoš, P. ∙ Shan, H. ∙ Wang, C. ...

**Sustainable water generation: grand challenges in continuous atmospheric water harvesting**

_Energy Environ. Sci._

2022; **15**:3223-3235

These advantages show the great potential of SBEC used for practical solar electricity generation, attracting tremendous research interest. This article first summarizes the existing relevant studies and their basic operating mechanisms, then proposes potential improvement directions. With the current research showing that this technology can generate efficiency gains of an impressive ∼10%[7](#)

7.

Li, R. ∙ Wu, M. ∙ Aleid, S. ...

**An integrated solar-driven system produces electricity with fresh water and crops in arid regions**

_Cell Reports Physical Science._

2022; **3**, 100781

,[8](#)

8.

Li, R. ∙ Shi, Y. ∙ Wu, M. ...

**Photovoltaic panel cooling by atmospheric water sorption–evaporation cycle**

_Nat. Sustain._

2020; **3**:636-643

based on commercial panels, and that the SBEC component is easily scalable for deployment, this technology may be a transformative one for PV power generation in the future.

### SBEC technology development and basic operating mechanisms

Motivated by mammals’ perspiration, several works with SBEC that used huge water vapor evaporation enthalpy (the highest among all room-temperature liquids[11](#)

11.

Li, R. ∙ Wang, W. ∙ Shi, Y. ...

**Advanced Material Design and Engineering for Water-Based Evaporative Cooling**

_Adv. Mater._

2023;, 2209460

) to cool systems effectively were explored for electronic cooling[12](#)

12.

Wang, C. ∙ Hua, L. ∙ Yan, H. ...

**A Thermal Management Strategy for Electronic Devices Based on Moisture Sorption-Desorption Processes**

_Joule._

2020; **4**:435-447

and battery thermal management.[13](#)

13.

Xu, J. ∙ Chao, J. ∙ Li, T. ...

**Near-Zero-Energy Smart Battery Thermal Management Enabled by Sorption Energy Harvesting from Air**

_ACS Cent. Sci._

2020; **6**:1542-1554

The primary mechanism of evaporative cooling can be divided into two major stages. The sorbent attached to the surface adsorbs atmospheric moisture in high relative humidity (RH) and low-temperature conditions (such as night). Then the adsorbent desorbs when the device dissipates heat ([Figure 2](#fig2)D). During this stage, the device can get extra cooling capacity from the water-vapor-releasing process in the sorbent. Several significant issues exist for this promising cooling technology used in solar electricity generation, notably how to balance the cycle time of desorption and adsorption and develop the adsorbent based on the desorption temperature under such scenarios.

[![](https://www.cell.com/cms/10.1016/j.joule.2024.01.006/asset/9c37657e-a66f-4892-af56-8995016280f1/main.assets/gr2.jpg)](https://www.cell.com/cms/10.1016/j.joule.2024.01.006/asset/ae01e1ac-742b-44ec-ab6f-54bd4cd6557b/main.assets/gr2_lrg.jpg "View full size image in a new tab")

Figure 2 Mechanism and recent progress of PV-sorbent systems

Three different solar PV structure designs are presented in [Figures 2](#fig2)A–2C. The conventional one ([Figure 2](#fig2)A) depicts the scenario in which the PV panel dissipates heat mainly by natural convection and thermal radiation. According to outdoor experiment data under Shanghai conditions,[6](#)

6.

Li, Z. ∙ Ma, T. ∙ Ji, F. ...

**A Hygroscopic Composite Backplate Enabling Passive Cooling of Photovoltaic Panels**

_ACS Energy Lett._

2023; **8**:1921-1928

the temperature of the back sheet can reach over 65°C. To overcome the inevitable high-temperature conditions, a PV panel with atmospheric water harvesting (AWH) was first reported in 2020[8](#)

8.

Li, R. ∙ Shi, Y. ∙ Wu, M. ...

**Photovoltaic panel cooling by atmospheric water sorption–evaporation cycle**

_Nat. Sustain._

2020; **3**:636-643

([Figure 2](#fig2)B). The harvester was equipped with carbon-nanotube (CNT)-embedded, cross-linked polyacrylamide (PAM) as substrate and calcium chloride hygroscopic salt, resulting in the composite sorbent PAM-CNT-CaCl2. This sorbent placed on the back sheet adsorbed water vapor at night and utilized the heat dissipation of PV modules during the day to achieve adsorbent desorption and cooling of PV modules. During the desorption process, the water vapor in the adsorbent was released, creating a localized high-humidity environment in the space near the PV panels. Therefore, this study utilized water vapor as an additional product and constructed a condensing surface behind the back sheet to condense the released water vapor to obtain liquid drinking water. This device exhibited an impressive 13%–19% increase in electricity generation during the outdoor experiments compared to the baseline scenario. The AWH-based cooling system, which was also a form of an SBEC module, provided an average cooling capacity of 295 W m−2 under 1.0 kW m−2 of indoor solar irradiation. The coupled water and electricity production has brought more possibilities for use-case scenarios in arid regions. Based on this concept, the same research group developed a new greenhouse planting scenario for the energy-water-food nexus.[6](#)

6.

Li, Z. ∙ Ma, T. ∙ Ji, F. ...

**A Hygroscopic Composite Backplate Enabling Passive Cooling of Photovoltaic Panels**

_ACS Energy Lett._

2023; **8**:1921-1928

In this study, water generated by the AWH system behind PV modules was used to irrigate plants in a small greenhouse. The average water collecting rate during the ongoing outdoor experiments was about 0.6 L m−2 day−1, enabling a high survival rate of crops (95%) for food supply in arid Saudi Arabia.

The primary purpose of the above two works is to reduce the temperature of PV panels through sorbent-based evaporative cooling while producing drinking water. Water production and the utilization of the water vapor released is unnecessary for cooling, and the additional condensing chamber forms an increased thermal resistance on the back of the PV panel. Besides, the adsorption process of the adsorbent at night also requires an additional fan to maintain the adsorption process, which increases the system’s complexity.

Hence, an SBEC-PV panel without an AWH-based cooling system was built by Li and colleagues.[6](#)

6.

Li, Z. ∙ Ma, T. ∙ Ji, F. ...

**A Hygroscopic Composite Backplate Enabling Passive Cooling of Photovoltaic Panels**

_ACS Energy Lett._

2023; **8**:1921-1928

Similar to the previous work,[7](#)

7.

Li, R. ∙ Wu, M. ∙ Aleid, S. ...

**An integrated solar-driven system produces electricity with fresh water and crops in arid regions**

_Cell Reports Physical Science._

2022; **3**, 100781

,[8](#)

8.

Li, R. ∙ Shi, Y. ∙ Wu, M. ...

**Photovoltaic panel cooling by atmospheric water sorption–evaporation cycle**

_Nat. Sustain._

2020; **3**:636-643

the device was loaded with the PAM/alginate hydrogel with CaCl2, but the bulk sample was encapsulated in polytetrafluoroethylene (PTFE) film and directly exposed to air ([Figure 2](#fig2)C). With this design, the water vapor released from the adsorbent was not recycled using the condensing surface. Instead, it was released directly into the air, lowering the thermal resistance for elevated heat exchange between the back of the prototype and the ambient air. In this study, based on laboratory production conditions, it is estimated that every square meter of SBEC module costs $4.56 (about 7.7% of the total PV panel price), which amount can be significantly reduced in the future with large-scale production. The experimental data in this study provided a comprehensive demonstration of the combined effects of back sheet cooling assisted by sorbents.

Whereas the desorption process of the adsorbent on the back sheet surface results in evaporative cooling benefits to the system, the adsorbent assembly introduces an increased thermal resistance on the back of the PV panel. The researchers used three identical experimental sets: one control module, one with an adsorbent module attached to the back, and one with thermal insulation attached to the back. During the whole daytime (6:00−18:00) experiment, the average temperature reduction was 3.5°C compared to the original PV panel (

in [Figure 2](#fig2)E and “Cooling benefits” in [Figure 2](#fig2)F). Compared to the back-insulated PV panel, the average temperature reduction was much higher: as much as 8.7°C (

in [Figure 2](#fig2)E). The technical solution was also validated in another study with a similar structure design, which allowed the commercial PV module to reach a temperature drop of 17°C under standard test conditions (1,000 W m−2).[14](#)

14.

Pu, S. ∙ Fu, J. ∙ Liao, Y. ...

**Promoting Energy Efficiency via a Self-Adaptive Evaporative Cooling Hydrogel**

_Adv. Mater._

2020; **32**, 1907307

This solution is straightforward to integrate with existing PV panel structures, and in existing studies, the researchers also modified existing commercial PV panels. Besides, the adsorbent used in these studies was inexpensive and easily synthesized on a scalable basis, enabling a broader range of applications to enhance the efficiency of PV panels for practical needs. Considering the significant share of PV power generation in overall electricity production, the plan to retrofit PV panels by adding components undoubtedly has a significant social impact.

### A bright future, but still a need to overcome interdisciplinary challenges

Different products, such as electricity and water, can be generated simultaneously. Hence, two things must be comprehensively considered in future SBEC-PV panels. First, the researchers should carefully choose the most desired products for the entire system. Based on that, constructing a reliable and high-efficiency SBEC module should be evaluated, considering the critical metrics for the desired final product. Three potential conversion products of moisture-driven SBEC-PV panels are electricity from the solar panel, inevitable heat, and condensed water during desorption (as shown in [Figure 3](#fig3)A). Under specific evaluation systems, structural designs reflected by different requirements in diverse scenarios should occur. For example, in the first two studies described in this article,[7](#)

7.

Li, R. ∙ Wu, M. ∙ Aleid, S. ...

**An integrated solar-driven system produces electricity with fresh water and crops in arid regions**

_Cell Reports Physical Science._

2022; **3**, 100781

,[8](#)

8.

Li, R. ∙ Shi, Y. ∙ Wu, M. ...

**Photovoltaic panel cooling by atmospheric water sorption–evaporation cycle**

_Nat. Sustain._

2020; **3**:636-643

to simultaneously obtain valuable water resources in arid environments, the heat dissipation of the back sheet was sacrificed to some extent compared to the last study. However, the core goal of these two studies is still to obtain a considerable amount of electricity. Similarly, if food production is the core goal, there will inevitably be new system design requirements focusing more on sustainable water co-production. Combining the obtained electricity and water to produce clean fuels is theoretically feasible; this also needs an optimized design. In summary, since SBEC-PV can provide various products and has excellent flexibility in combining with other components, an evaluation system should be developed based on the main objectives to achieve the optimal structure and system selection under specified conditions. While current research focuses on conceptual demonstrations, future commercialization promotion urgently requires establishing and optimizing technical analysis. A modular technical analysis model is also needed to meet various practical needs for the SBEC-PV system. Such a system ought to be highly flexible; its cooling effect is closely tied to multiple parameters such as system design, adsorbent type, packaging method and density, and system operation strategy.

[![](https://www.cell.com/cms/10.1016/j.joule.2024.01.006/asset/4b05543a-d90c-4716-b1e1-eac3fb36c22b/main.assets/gr3.jpg)](https://www.cell.com/cms/10.1016/j.joule.2024.01.006/asset/03da160d-79c0-48ab-88d5-96cbb9dcb366/main.assets/gr3_lrg.jpg "View full size image in a new tab")

Figure 3 Production and potential structure design under different evaluation indicators

No matter how the evaluation indicators are formulated, constructing a reliable high-efficiency SBEC module will be the core of the polygeneration SBEC system. The characteristics of the adsorbent are crucial. In the above studies, the hydrogel was used as the matrix and chloride was loaded as the adsorbent. This composite adsorbent can fully utilize the high humidity conditions at night for adsorption while also completing partial desorption at the lower heat source temperature provided by the photothermal plate.[15](#)

15.

Poredoš, P. ∙ Shan, H. ∙ Wang, R.

**Dehumidification with solid hygroscopic sorbents for low-carbon air conditioning**

_Joule._

2022; **6**:1390-1393

,[16](#)

16.

Matsumoto, K. ∙ Sakikawa, N. ∙ Miyata, T.

**Thermo-responsive gels that absorb moisture and ooze water**

_Nat. Commun._

2018; **9**:2315

However, for future practical application scenarios, existing research has not considered the potential risk of composite adsorbent dissolution. During continuous rainy weather, the composite adsorbent may deliquesce and lead to salt loss, while the salt solution will corrode the PV panels and cause system failure. Besides, although PTFE protective film was used on the back of the adsorbent module in the study, we still need to develop different and reliable adsorbent packaging solutions that adapt to various practical working conditions. In current research, the cost of PTFE film accounts for ∼60% of the total raw material cost ($2.8 m−2 vs. $4.56 m−2), so it is necessary to develop cheaper and more reliable packaging methods.

Therefore, it is necessary to consider optimizing the adsorbent to the practical scenario, such as replacing the existing composite adsorbent with a significant water uptake, high desorption enthalpy, and low desorption temperature physical adsorbent (e.g., MOFs[17](#)

17.

Liu, X. ∙ Wang, X. ∙ Kapteijn, F.

**Water and Metal-Organic Frameworks: From Interaction toward Utilization**

_Chem. Rev._

2020; **120**:8303-8377

). We have summarized five key indicators for researchers to consider in their future exploration of the sorbent for SBEC-PV systems in [Figure 2](#fig2)G: high stability (which is essential for long-term operation); low price (which is vital for large-scale promotion and practical application); ease of packaging (which is important for system construction); non-corrosiveness (this is necessary to avoid the decrease in the lifespan of photovoltaic panels caused by the addition of the SBEC system); and high water uptake (high water uptake is beneficial for providing greater cooling capacity to the PV panel). In previous research on AWH, extreme arid climatic conditions, which often had the lowest relative humidity and the highest temperature during the day, were frequently used to select adsorbents. Under these harsh operating conditions, it can be ensured that the adsorbent can adsorb at any time and has the potential for multi-cycle working modes. Hence, this scheme dramatically increases the difficulty of material screening and performance requirements. To achieve efficient thermal management of photovoltaic modules, the adsorbent should only undergo desorption during the day, which means that the primary operating mode of the adsorbent may be a single daily cycle. At present, the existing SBEC-PV working cycle mode is that the adsorbent adsorbs at night and desorbs during the day, driven by the waste heat generated by the photovoltaic panel. This is considering the working mode of photovoltaic panels, which do not work at night and generate electricity during the day. Therefore, full consideration should be given to the favorable aspects of a high-humidity environment at night for material selection. As shown in [Figure 3](#fig3)B, with the climate data from Cairo, even in the summer with a typical arid climate, the relative humidity still exceeds 60% for much of the night, meaning that adsorbents with higher working capacity can be selected without being limited to the lowest humidity throughout the day. Besides, due to the increased thermal resistance brought by the adsorbent module, it is necessary to optimize the adsorbent module’s thickness to balance the adsorbent module’s water adsorption capacity and the device’s thermal resistance. Due to similar application requirements, this technology can be screened based on the extensive adsorbent exploration in the existing AWH field.[18](#)

18.

Song, Y. ∙ Zeng, M. ∙ Wang, X. ...

**Hierarchical Engineering of Sorption-Based Atmospheric Water Harvesters**

_Adv. Mater._

2023;, 2209134

The comparative experimental data from the existing study exposes another hidden concern of this evaporative cooling method. Namely, if the adsorbent material attached to the back is entirely desorbed, the heat transfer of the PV plate significantly deteriorates. If the PV panel with thermal insulation is compared with the original PV panel, the temperature of the back sheet increases by more than 5°C (

in [Figure 2](#fig2)E). This means that, in existing studies, most cooling capacity benefits brought by evaporative cooling are used to overcome the losses caused by thermal resistance from an additional sorbent layer. Meanwhile, if the desorption of the adsorbent cannot continue throughout the day, the SBEC module will not be able to provide cooling capacity for the PV panel after complete desorption and may form thermal resistance to increase the temperature of the PV panel, leading to a decrease in the efficiency of the PV panel. To solve this problem, it is also necessary to improve the thermal conductivity of the adsorbent at the material level to minimize thermal resistance and optimize the operation strategy as much as possible. At the system level, although current research has demonstrated the enormous potential of this system, it is still necessary to clarify the additional effects of installing the SBEC module on the PV board in the future—especially whether the local humidity changes caused by the adsorbent adsorption/desorption cycle have an impact on the efficiency of the PV panel and whether salt spray can be generated and corrode the PV device during desorption. At the same time, the packaging method of the material also needs to be further optimized to ensure the stable operation of the adsorbent under different climatic conditions. This technology can also be combined with technologies such as radiative sky cooling to improve PV efficiency further.[19](#)

19.

Li, J. ∙ Wang, X. ∙ Liang, D. ...

**A tandem radiative/evaporative cooler for weather-insensitive and high-performance daytime passive cooling**

_Sci. Adv._

2022; **8**, eabq0411

Water, energy, and food constitute the basic conditions for life. Harvesting electricity more efficiently and achieving water production simultaneously exhibits great potential to alleviate global challenges. Studies have already demonstrated that the efficiency of PV panels can be increased by ∼20% with the addition of SBEC components,[7](#)

7.

Li, R. ∙ Wu, M. ∙ Aleid, S. ...

**An integrated solar-driven system produces electricity with fresh water and crops in arid regions**

_Cell Reports Physical Science._

2022; **3**, 100781

which may bring significant benefits to the whole PV sector (detailed comparative performance of sorbent-based evaporative cooling for PV can be found in the [supplemental information](#app-1)). Combined with agricultural systems, such devices achieve a comprehensive supply of water, energy, and food, which provides potential support for increasing production in arid areas and even the exploration of extraterrestrial planets in the future.

Significant progress in the SBEC-PV system has been achieved using different structure designs and mechanism analyses. However, realizing truly reliable high-efficiency water-electricity generation is still challenging for conventional SBEC systems. Herein, we analyzed the recently reported works to provide possible research paths and demonstrate potential for further studies. These works could promote the combination of SBEC and PV systems. This technology, which has excellent potential for application and has reached a critical point to scale up, will in future play a more significant role in deploying renewable energy. However, we still need co-efforts from scientists within materials, thermal and electrical engineering scientists, and device optimization frameworks to make this promising system meet different practical needs.

## Acknowledgments

This work was supported by the National Natural Science Foundation of China (no. 51336004) and the Fundamental Research Funds for the Central Universities, Shanghai Jiao Tong University. Special thanks to Prof. <PRESIDIO_ANONYMIZED_PERSON>, Prof. Yanjun Dai, and Dr. Audun Bull Kristiansen of Shanghai Jiao Tong University for their support in this work!

### Declaration of interests

The authors declare no competing interests.

## Supplemental information (2)

Document S1. Supplemental information

Document S2. Article plus supplemental information

## References

Chang, N.L. ∙ Dehghanimadvar, M. ∙ Egan, R.

**The cost of risk mitigation—Diversifying the global solar PV supply chain**

_Joule._

2022; **6**:2686-2688

van Helden, W.G.J. ∙ van Zolingen, R.J.C. ∙ Zondag, H.A.

**PV thermal systems: PV panels supplying renewable electricity and heat**

_Progress in Photovoltaics._

2004; **12**:415-426

Yao, J. ∙ Dou, P. ∙ Zheng, S. ...

**Co-generation ability investigation of the novel structured PVT heat pump system and its effect on the “Carbon neutral” strategy of Shanghai**

_Energy._

2022; **239**, 121863

Kettle, J. ∙ Aghaei, M. ∙ Ahmad, S. ...

**Review of technology specific degradation in crystalline silicon, cadmium telluride, copper indium gallium selenide, dye sensitised, organic and perovskite solar cells in photovoltaic modules: Understanding how reliability improvements in mature technologies can enhance emerging technologies**

_Prog. Photovolt._

2022; **30**:1365-1392

Li, Z. ∙ Ma, T. ∙ Ji, F. ...

**A Hygroscopic Composite Backplate Enabling Passive Cooling of Photovoltaic Panels**

_ACS Energy Lett._

2023; **8**:1921-1928

Li, R. ∙ Wu, M. ∙ Aleid, S. ...

**An integrated solar-driven system produces electricity with fresh water and crops in arid regions**

_Cell Reports Physical Science._

2022; **3**, 100781

Li, R. ∙ Shi, Y. ∙ Wu, M. ...

**Photovoltaic panel cooling by atmospheric water sorption–evaporation cycle**

_Nat. Sustain._

2020; **3**:636-643

Poredoš, P. ∙ Shan, H. ∙ Wang, C. ...

**Sustainable water generation: grand challenges in continuous atmospheric water harvesting**

_Energy Environ. Sci._

2022; **15**:3223-3235

IEA

**Net Zero by 2050**

International Energy Agency, 2021

Li, R. ∙ Wang, W. ∙ Shi, Y. ...

**Advanced Material Design and Engineering for Water-Based Evaporative Cooling**

_Adv. Mater._

2023;, 2209460

Wang, C. ∙ Hua, L. ∙ Yan, H. ...

**A Thermal Management Strategy for Electronic Devices Based on Moisture Sorption-Desorption Processes**

_Joule._

2020; **4**:435-447

Xu, J. ∙ Chao, J. ∙ Li, T. ...

**Near-Zero-Energy Smart Battery Thermal Management Enabled by Sorption Energy Harvesting from Air**

_ACS Cent. Sci._

2020; **6**:1542-1554

Pu, S. ∙ Fu, J. ∙ Liao, Y. ...

**Promoting Energy Efficiency via a Self-Adaptive Evaporative Cooling Hydrogel**

_Adv. Mater._

2020; **32**, 1907307

Poredoš, P. ∙ Shan, H. ∙ Wang, R.

**Dehumidification with solid hygroscopic sorbents for low-carbon air conditioning**

_Joule._

2022; **6**:1390-1393

Matsumoto, K. ∙ Sakikawa, N. ∙ Miyata, T.

**Thermo-responsive gels that absorb moisture and ooze water**

_Nat. Commun._

2018; **9**:2315

Liu, X. ∙ Wang, X. ∙ Kapteijn, F.

**Water and Metal-Organic Frameworks: From Interaction toward Utilization**

_Chem. Rev._

2020; **120**:8303-8377

Song, Y. ∙ Zeng, M. ∙ Wang, X. ...

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