Exploitation of sustainable energy sources requires the use of unique conversion and storage systems,such as solar panels,batteries,fuel cells,and electronic equipment.Thermal load management of these energy conversio...Exploitation of sustainable energy sources requires the use of unique conversion and storage systems,such as solar panels,batteries,fuel cells,and electronic equipment.Thermal load management of these energy conversion and storage systems is one of their challenges and concerns.In this article,the thermal management of these systems using thermoelectric modules is reviewed.The results show that by choosing the right option to remove heat from the hot side of the thermoelectric modules,it will be a suitable local cooling,and the thermoelectric modules increase the power and lifespan of the system by reducing the spot temperature.Thermoelectric modules were effective in reducing panel temperature.They increase the time to reach a temperature above 50℃ in batteries by 3 to 4 times.Also,in their integration with fuel cells,they increase the power density of the fuel cell.展开更多
The HCPB concept has been a European DEMO reference concept for nearly one decade. Detailed thermal-hydraulic study on the control behavior of the whole system is one of the important parts of this development. The th...The HCPB concept has been a European DEMO reference concept for nearly one decade. Detailed thermal-hydraulic study on the control behavior of the whole system is one of the important parts of this development. The thermal-hydraulic effect of the TBM-combined cooling circuit during a cyclic operation in ITER has been studied using the system code RELAP5. The RELAP5 is based on an one-dimensional, transient two-fluid model for the flow of a two-phase steam-water mixture that can contain noncondensable components like Helium. The RELAP5models are modified to take the cyclic operation of the circulator, heat, exchanger, bypass, valves etc in to account. A sequence of operational phases is investigated, starting from the cold state through the heating phase that brings the system to a stand-by condition, followed by typical power cycles applied in ITER. The results show that the implemented control mechanisms keep the inlet temperature to the TBM and the total mass flow rate at the required values through all phases.展开更多
The advancement of sophisticated smart windows exhibiting superior thermoregulation capabilities in both solar spectrum and long-wave infrared range maintains a prominent objective for researchers in this field.In thi...The advancement of sophisticated smart windows exhibiting superior thermoregulation capabilities in both solar spectrum and long-wave infrared range maintains a prominent objective for researchers in this field.In this study,a Janus window is proposed and prepared based on polymer-stabilized liquid-crystal films/thermochromic materials.It can achieve switchable front long-wave infrared emissivity(ε_(Front))and solar modulation ability(ΔT_(sol))through dynamic flipping,making it suitable for different seasonal energy-saving requirements.Outdoor experiments show that under daytime illumination,the indoor temperature decreases by 8℃,and the nighttime temperature drops by 5℃.MATLAB simulation calculations indicate that the daytime cooling power is 93 W m^(-2),while the nighttime cooling power reaches 142 W m^(-2).Interestingly,by modifying the conductive layer,it can effectively shield electromagnetic radiation(within the X-band frequency range(8.2-12.4)GHz).Energy simulation reveals the substantial superiority of this device in energy savings compared with single-layer polymer-stabilized liquid crystal,poly(N-isopropyl acrylamide),and normal glass when applied in different climate zones.This research presents a compelling opportunity for the development of sophisticated smart windows characterized by exceptional thermoregulation capabilities.展开更多
Ground-state cooling of mesoscopic mechanical objects is still a major challenge in the unresolved-sideband regime.We present a frequency modulation(FM)scheme to achieve cooling of the mechanical resonator to its grou...Ground-state cooling of mesoscopic mechanical objects is still a major challenge in the unresolved-sideband regime.We present a frequency modulation(FM)scheme to achieve cooling of the mechanical resonator to its ground-state in a double-cavity optomechanical system containing a mechanical resonator.The mean phonon number is determined by numerically solving a set of differential equations derived from the quantum master equations.Due to efficient suppression of Stokes heating processes in the presence of FM,the ground-state cooling,indicated by numerical calculations,is significantly achievable,regardless of whether in the resolved-sideband regime or the unresolved-sideband regime.Furthermore,by choosing parameters reasonably,the improvement of the quantum cooling limit is found to be capable of being positively correlated with the modulation frequency.This method provides new insight into quantum manipulation and creates more possibilities for applications of quantum devices.展开更多
New generation thermo-mechanical control process(TMCP) based on ultra-fast cooling is being widely adopted in plate mill to product high-performance steel material at low cost. Ultra-fast cooling system is complex b...New generation thermo-mechanical control process(TMCP) based on ultra-fast cooling is being widely adopted in plate mill to product high-performance steel material at low cost. Ultra-fast cooling system is complex because of optimizing the temperature control error generated by heat transfer mathematical model and process parameters. In order to simplify the system and improve the temperature control precision in ultra-fast cooling process, several existing models of case-based reasoning(CBR) model are reviewed. Combining with ultra-fast cooling process, a developed R5 CBR model is proposed, which mainly improves the case representation, similarity relation and retrieval module. Certainty factor is defined in semantics memory unit of plate case which provides not only internal data reliability but also product performance reliability. Similarity relation is improved by defined power index similarity membership function. Retrieval process is simplified and retrieval efficiency is improved apparently by windmill retrieval algorithm. The proposed CBR model is used for predicting the case of cooling strategy and its capability is superior to traditional process model. In order to perform comprehensive investigations on ultra-fast cooling process, different steel plates are considered for the experiment. The validation experiment and industrial production of proposed CBR model are carried out, which demonstrated that finish cooling temperature(FCT) error is controlled within±25℃ and quality rate of product is more than 97%. The proposed CBR model can simplify ultra-fast cooling system and give quality performance for steel product.展开更多
This paper proposed a new function of photovoltaic thermal(PVT)module to produce nocturnal cool water not just only generating electrical power and hot water during daytime.Experimental tests were carried out under Ch...This paper proposed a new function of photovoltaic thermal(PVT)module to produce nocturnal cool water not just only generating electrical power and hot water during daytime.Experimental tests were carried out under Chiang Mai tropical climate with a 200 Wp monocrystalline PVT module having dimensions of 1.601 m×0.828 m connected with two water tanks each of 60 L taken for hot and cool water storages.The module was facing south with 18o inclination.The electrical load was a 200 W halogen lamp.From experiments,by taking the module as a nocturnal radiative cooling surface,the cool water temperature in the cool storage tank could be reduced 2℃–3℃each night and the temperature could be reduced from 31.5℃to 22.1℃within 4 consecutive days.The cool water at approximately 23℃was also used to cool down the PVT module from noon when the PVT module temperature was rather high,and then the module temperature immediately dropped around 5℃and approximately 10%increase of electrical power could be achieved.A set of mathematical models was also developed to predict the PVT module temperature and the hot water temperature including the cool water temperature in the storage tanks during daytime and nighttime.The simulated results agreed well with the experimental data.展开更多
The development of vehicle integrated photovoltaics-powered electric vehicles (VIPV-EV) significantly reduces CO<sub>2</sub> emissions from the transport sector to realize a decarbonized society. Although ...The development of vehicle integrated photovoltaics-powered electric vehicles (VIPV-EV) significantly reduces CO<sub>2</sub> emissions from the transport sector to realize a decarbonized society. Although long-distance driving of VIPV-EV without electricity charging is expected in sunny regions, driving distance of VIPV-EV is affected by climate conditions such as solar irradiation and temperature rise of PV modules. In this paper, detailed analytical results for effects of climate conditions such as solar irradiation and temperature rise of PV modules upon driving distance of the VIPV-EV were presented by using test data for Toyota Prius and Nissan Van demonstration cars installed with high-efficiency InGaP/GaAs/InGaAs 3-junction solar cell modules with a module efficiency of more than 30%. The temperature rise of some PV modules studied in this study was shown to be expressed by some coefficients related to solar irradiation, wind speed and radiative cooling. The potential of VIPV-EV to be deployed in 10 major cities was also analyzed. Although sunshine cities such as Phoenix show the high reduction ratio of driving range with 17% due to temperature rise of VIPV modules, populous cities such as Tokyo show low reduction ratio of 9%. It was also shown in this paper that the difference between the driving distance of VIPV-EV driving in the morning and the afternoon is due to PV modules’ radiative cooling. In addition, the importance of heat dissipation of PV modules and the development of high-efficiency PV modules with better temperature coefficients was suggested in order to expand driving range of VIPV-EV. The effects of air-conditioner usage and partial shading in addition to the effects of temperature rise of VIPV modules were suggested as the other power losses of VIPV-EV.展开更多
All-season thermal management with zero energy consumption and emissions is more crucial to global decarbonization over traditional energy-intensive cooling/heating systems.However,the static single thermal management...All-season thermal management with zero energy consumption and emissions is more crucial to global decarbonization over traditional energy-intensive cooling/heating systems.However,the static single thermal management for cooling or heating fails to self-regulate the temperature in dynamic seasonal temperature condition.Herein,inspired by the dual-temperature regulation function of the fur color changes on the backs and abdomens of penguins,a smart thermal management composite hydrogel(PNA@H-PM Gel)system was subtly created though an"on-demand"dual-layer structure design strategy.The PNA@H-PM Gel system features synchronous solar and thermal radiation modulation as well as tunable phase transition temperatures to meet the variable seasonal thermal requirements and energy-saving demands via self-adaptive radiative cooling and solar heating regulation.Furthermore,this system demonstrates superb modulations of both the solar reflectance(ΔR=0.74)and thermal emissivity(ΔE=0.52)in response to ambient temperature changes,highlighting efficient temperature regulation with average radiative cooling and solar heating effects of 9.6℃in summer and 6.1℃in winter,respectively.Moreover,compared to standard building baselines,the PNA@H-PM Gel presents a more substantial energy-saving cooling/heating potentials for energy-efficient buildings across various regions and climates.This novel solution,inspired by penguins in the real world,will offer a fresh approach for producing intelligent,energy-saving thermal management materials,and serve for temperature regulation under dynamic climate conditions and even throughout all seasons.展开更多
When converting solar energy to electricity,a big proportion of energy is not converted for electricity but for heating PV cells,resulting in increased cell temperature and reduced electrical efficiency.Many cooling t...When converting solar energy to electricity,a big proportion of energy is not converted for electricity but for heating PV cells,resulting in increased cell temperature and reduced electrical efficiency.Many cooling technologies have been developed and used for PV modules to lower cell temperature and boost electric energy yield.However,little crucial review work was proposed to comment cooling technologies for PV modules.Therefore,this paper has provided a thorough review of the up-to-date development of existing cooling technologies for PV modules,and given appropriate comments,comparisons and discussions.According to the ways or principles of cooling,existing cooling technologies have been classified as fluid medium cooling(air cooling,water cooling and nanofluids cooling),optimizing structural configuration cooling and phase change materials cooling.Potential influential factors and sub-methods were collected from the review work,and their contributions and impact have been discussed to guide future studies.Although most cooling technologies reviewed in this paper are matured,there are still problems need to be solved,such as the choice of cooling fluid and its usability for specific regions,the fouling accumulation and cleaning of enhanced heat exchangers with complex structures,the balance between cooling cost and net efficiency of PV modules,the cooling of circulating water in tropical areas and the freezing of circulating water in cold areas.To be advocated,due to efficient heat transfer and spectral filter characters,nanofluids can promote the effective matching of solar energy at both spectral and spatial scales to achieve orderly energy utilization.展开更多
The operational temperature rise of photovoltaic(PV)panels reduces their power generation efficiency and shortens their lifespan.Hygroscopic hydrogel-based evaporative cooling technology provides a promising solution ...The operational temperature rise of photovoltaic(PV)panels reduces their power generation efficiency and shortens their lifespan.Hygroscopic hydrogel-based evaporative cooling technology provides a promising solution for PV cooling due to high-enthalpy water evaporation.However,current hydrogels remain plagued by cooling interface mismatch and environmental concerns,which limit their practical implementation.Herein,a“green”and self-adhesive hygroscopic hydrogel consisting only of cheap lotus root powder and LiCl is designed,which can form robust interfacial adhesion with PV panels for efficient and durable cooling.Leveraging its compelling hygroscopicity,the hydrogel is able to rapidly capture moisture to recover cooling capacity,thus achieving self-sustained cooling.Besides,the“salting-in”effect brought by LiCl endows the hydrogel with notable softness and self-adhesiveness,which enables it to tightly combine with PV panels to optimize heat conduction and improve cooling efficiency.As a result,under 1.0 kW m^(-2)illumination,a PV temperature drop of 18.2℃ and a cooling power of 358 W m^(-2)were delivered by attaching the hydrogel to the rear of the PV panel,accompanied by a 7.7%improvement in energy efficiency.Overall,this self-sustained passive cooling strategy,activated by the all-natural hydrogel,sheds light on the development of PV thermal management.展开更多
文摘Exploitation of sustainable energy sources requires the use of unique conversion and storage systems,such as solar panels,batteries,fuel cells,and electronic equipment.Thermal load management of these energy conversion and storage systems is one of their challenges and concerns.In this article,the thermal management of these systems using thermoelectric modules is reviewed.The results show that by choosing the right option to remove heat from the hot side of the thermoelectric modules,it will be a suitable local cooling,and the thermoelectric modules increase the power and lifespan of the system by reducing the spot temperature.Thermoelectric modules were effective in reducing panel temperature.They increase the time to reach a temperature above 50℃ in batteries by 3 to 4 times.Also,in their integration with fuel cells,they increase the power density of the fuel cell.
基金The project supported by European Fusion Development Agreement (EFDA) Technology Work Program
文摘The HCPB concept has been a European DEMO reference concept for nearly one decade. Detailed thermal-hydraulic study on the control behavior of the whole system is one of the important parts of this development. The thermal-hydraulic effect of the TBM-combined cooling circuit during a cyclic operation in ITER has been studied using the system code RELAP5. The RELAP5 is based on an one-dimensional, transient two-fluid model for the flow of a two-phase steam-water mixture that can contain noncondensable components like Helium. The RELAP5models are modified to take the cyclic operation of the circulator, heat, exchanger, bypass, valves etc in to account. A sequence of operational phases is investigated, starting from the cold state through the heating phase that brings the system to a stand-by condition, followed by typical power cycles applied in ITER. The results show that the implemented control mechanisms keep the inlet temperature to the TBM and the total mass flow rate at the required values through all phases.
基金supported by the National Natural Science Foundation of China(52372279,52103071,52203322,52473289,52303220)the Interdisciplinary Research Project for Young Teachers of USTB(Fundamental Research Funds for the Central Universities in China,FRF-IDRY-GD22-001)。
文摘The advancement of sophisticated smart windows exhibiting superior thermoregulation capabilities in both solar spectrum and long-wave infrared range maintains a prominent objective for researchers in this field.In this study,a Janus window is proposed and prepared based on polymer-stabilized liquid-crystal films/thermochromic materials.It can achieve switchable front long-wave infrared emissivity(ε_(Front))and solar modulation ability(ΔT_(sol))through dynamic flipping,making it suitable for different seasonal energy-saving requirements.Outdoor experiments show that under daytime illumination,the indoor temperature decreases by 8℃,and the nighttime temperature drops by 5℃.MATLAB simulation calculations indicate that the daytime cooling power is 93 W m^(-2),while the nighttime cooling power reaches 142 W m^(-2).Interestingly,by modifying the conductive layer,it can effectively shield electromagnetic radiation(within the X-band frequency range(8.2-12.4)GHz).Energy simulation reveals the substantial superiority of this device in energy savings compared with single-layer polymer-stabilized liquid crystal,poly(N-isopropyl acrylamide),and normal glass when applied in different climate zones.This research presents a compelling opportunity for the development of sophisticated smart windows characterized by exceptional thermoregulation capabilities.
基金supported by the National Natural Science Foundation of China(Grant No.62061028)the Foundation for Distinguished Young Scientists of Jiangxi Province(Grant No.20162BCB23009)+2 种基金the Open Research Fund Program of the State Key Laboratory of Low-Dimensional Quantum Physics(Grant No.KF202010)the Interdisciplinary Innovation Fund of Nanchang University(Grant No.9166-27060003-YB12)the Open Research Fund Program of Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education(Grant No.OEIAM202004)。
文摘Ground-state cooling of mesoscopic mechanical objects is still a major challenge in the unresolved-sideband regime.We present a frequency modulation(FM)scheme to achieve cooling of the mechanical resonator to its ground-state in a double-cavity optomechanical system containing a mechanical resonator.The mean phonon number is determined by numerically solving a set of differential equations derived from the quantum master equations.Due to efficient suppression of Stokes heating processes in the presence of FM,the ground-state cooling,indicated by numerical calculations,is significantly achievable,regardless of whether in the resolved-sideband regime or the unresolved-sideband regime.Furthermore,by choosing parameters reasonably,the improvement of the quantum cooling limit is found to be capable of being positively correlated with the modulation frequency.This method provides new insight into quantum manipulation and creates more possibilities for applications of quantum devices.
基金Supported by National Basic Research Program of China (973 Program,Grant No.2010CB630801)
文摘New generation thermo-mechanical control process(TMCP) based on ultra-fast cooling is being widely adopted in plate mill to product high-performance steel material at low cost. Ultra-fast cooling system is complex because of optimizing the temperature control error generated by heat transfer mathematical model and process parameters. In order to simplify the system and improve the temperature control precision in ultra-fast cooling process, several existing models of case-based reasoning(CBR) model are reviewed. Combining with ultra-fast cooling process, a developed R5 CBR model is proposed, which mainly improves the case representation, similarity relation and retrieval module. Certainty factor is defined in semantics memory unit of plate case which provides not only internal data reliability but also product performance reliability. Similarity relation is improved by defined power index similarity membership function. Retrieval process is simplified and retrieval efficiency is improved apparently by windmill retrieval algorithm. The proposed CBR model is used for predicting the case of cooling strategy and its capability is superior to traditional process model. In order to perform comprehensive investigations on ultra-fast cooling process, different steel plates are considered for the experiment. The validation experiment and industrial production of proposed CBR model are carried out, which demonstrated that finish cooling temperature(FCT) error is controlled within±25℃ and quality rate of product is more than 97%. The proposed CBR model can simplify ultra-fast cooling system and give quality performance for steel product.
文摘This paper proposed a new function of photovoltaic thermal(PVT)module to produce nocturnal cool water not just only generating electrical power and hot water during daytime.Experimental tests were carried out under Chiang Mai tropical climate with a 200 Wp monocrystalline PVT module having dimensions of 1.601 m×0.828 m connected with two water tanks each of 60 L taken for hot and cool water storages.The module was facing south with 18o inclination.The electrical load was a 200 W halogen lamp.From experiments,by taking the module as a nocturnal radiative cooling surface,the cool water temperature in the cool storage tank could be reduced 2℃–3℃each night and the temperature could be reduced from 31.5℃to 22.1℃within 4 consecutive days.The cool water at approximately 23℃was also used to cool down the PVT module from noon when the PVT module temperature was rather high,and then the module temperature immediately dropped around 5℃and approximately 10%increase of electrical power could be achieved.A set of mathematical models was also developed to predict the PVT module temperature and the hot water temperature including the cool water temperature in the storage tanks during daytime and nighttime.The simulated results agreed well with the experimental data.
文摘The development of vehicle integrated photovoltaics-powered electric vehicles (VIPV-EV) significantly reduces CO<sub>2</sub> emissions from the transport sector to realize a decarbonized society. Although long-distance driving of VIPV-EV without electricity charging is expected in sunny regions, driving distance of VIPV-EV is affected by climate conditions such as solar irradiation and temperature rise of PV modules. In this paper, detailed analytical results for effects of climate conditions such as solar irradiation and temperature rise of PV modules upon driving distance of the VIPV-EV were presented by using test data for Toyota Prius and Nissan Van demonstration cars installed with high-efficiency InGaP/GaAs/InGaAs 3-junction solar cell modules with a module efficiency of more than 30%. The temperature rise of some PV modules studied in this study was shown to be expressed by some coefficients related to solar irradiation, wind speed and radiative cooling. The potential of VIPV-EV to be deployed in 10 major cities was also analyzed. Although sunshine cities such as Phoenix show the high reduction ratio of driving range with 17% due to temperature rise of VIPV modules, populous cities such as Tokyo show low reduction ratio of 9%. It was also shown in this paper that the difference between the driving distance of VIPV-EV driving in the morning and the afternoon is due to PV modules’ radiative cooling. In addition, the importance of heat dissipation of PV modules and the development of high-efficiency PV modules with better temperature coefficients was suggested in order to expand driving range of VIPV-EV. The effects of air-conditioner usage and partial shading in addition to the effects of temperature rise of VIPV modules were suggested as the other power losses of VIPV-EV.
基金the funding and generous support of the National Natural Science Foundation of China(52103263,52271249)the Key Project of International Science&Technology Cooperation of Shaanxi Province(2023-GHZD-09)+5 种基金the Key Project of Science Foundation of Education Department of Shaanxi Province(22JY011)the Key Project of Scientific Research and Development of Shaanxi Province(2023GXLH-070)the Qinchuangyuan"Scientist+Engineer"Team of Shaanxi Province(2023KXJ-069)the Key Research and Development Program of Shaanxi(2023-YBGY-488)the Sci-tech Innovation Team of Shaanxi Province(2024RS-CXTD-46)the Key Research and Development Program of Shaanxi Province(2020ZDLGY13-11).
文摘All-season thermal management with zero energy consumption and emissions is more crucial to global decarbonization over traditional energy-intensive cooling/heating systems.However,the static single thermal management for cooling or heating fails to self-regulate the temperature in dynamic seasonal temperature condition.Herein,inspired by the dual-temperature regulation function of the fur color changes on the backs and abdomens of penguins,a smart thermal management composite hydrogel(PNA@H-PM Gel)system was subtly created though an"on-demand"dual-layer structure design strategy.The PNA@H-PM Gel system features synchronous solar and thermal radiation modulation as well as tunable phase transition temperatures to meet the variable seasonal thermal requirements and energy-saving demands via self-adaptive radiative cooling and solar heating regulation.Furthermore,this system demonstrates superb modulations of both the solar reflectance(ΔR=0.74)and thermal emissivity(ΔE=0.52)in response to ambient temperature changes,highlighting efficient temperature regulation with average radiative cooling and solar heating effects of 9.6℃in summer and 6.1℃in winter,respectively.Moreover,compared to standard building baselines,the PNA@H-PM Gel presents a more substantial energy-saving cooling/heating potentials for energy-efficient buildings across various regions and climates.This novel solution,inspired by penguins in the real world,will offer a fresh approach for producing intelligent,energy-saving thermal management materials,and serve for temperature regulation under dynamic climate conditions and even throughout all seasons.
基金The authors gratefully acknowledge the funding support from the National Key R&D Program of China(No.2017YFC0702900).
文摘When converting solar energy to electricity,a big proportion of energy is not converted for electricity but for heating PV cells,resulting in increased cell temperature and reduced electrical efficiency.Many cooling technologies have been developed and used for PV modules to lower cell temperature and boost electric energy yield.However,little crucial review work was proposed to comment cooling technologies for PV modules.Therefore,this paper has provided a thorough review of the up-to-date development of existing cooling technologies for PV modules,and given appropriate comments,comparisons and discussions.According to the ways or principles of cooling,existing cooling technologies have been classified as fluid medium cooling(air cooling,water cooling and nanofluids cooling),optimizing structural configuration cooling and phase change materials cooling.Potential influential factors and sub-methods were collected from the review work,and their contributions and impact have been discussed to guide future studies.Although most cooling technologies reviewed in this paper are matured,there are still problems need to be solved,such as the choice of cooling fluid and its usability for specific regions,the fouling accumulation and cleaning of enhanced heat exchangers with complex structures,the balance between cooling cost and net efficiency of PV modules,the cooling of circulating water in tropical areas and the freezing of circulating water in cold areas.To be advocated,due to efficient heat transfer and spectral filter characters,nanofluids can promote the effective matching of solar energy at both spectral and spatial scales to achieve orderly energy utilization.
基金supported by the National Natural Science Foundation of China(52473033)。
文摘The operational temperature rise of photovoltaic(PV)panels reduces their power generation efficiency and shortens their lifespan.Hygroscopic hydrogel-based evaporative cooling technology provides a promising solution for PV cooling due to high-enthalpy water evaporation.However,current hydrogels remain plagued by cooling interface mismatch and environmental concerns,which limit their practical implementation.Herein,a“green”and self-adhesive hygroscopic hydrogel consisting only of cheap lotus root powder and LiCl is designed,which can form robust interfacial adhesion with PV panels for efficient and durable cooling.Leveraging its compelling hygroscopicity,the hydrogel is able to rapidly capture moisture to recover cooling capacity,thus achieving self-sustained cooling.Besides,the“salting-in”effect brought by LiCl endows the hydrogel with notable softness and self-adhesiveness,which enables it to tightly combine with PV panels to optimize heat conduction and improve cooling efficiency.As a result,under 1.0 kW m^(-2)illumination,a PV temperature drop of 18.2℃ and a cooling power of 358 W m^(-2)were delivered by attaching the hydrogel to the rear of the PV panel,accompanied by a 7.7%improvement in energy efficiency.Overall,this self-sustained passive cooling strategy,activated by the all-natural hydrogel,sheds light on the development of PV thermal management.