Transmission Of Solar Radiation Research Articles

Seasonality of spectral radiative fluxes and optical properties of Arctic sea ice during the spring–summer transition

The reflection, absorption, and transmittance of shortwave solar radiation by sea ice play crucial roles in physical and biological processes in the ice-covered Arctic Ocean and atmosphere. These sea-ice optical properties, particularly during the melt season, significantly impact energy fluxes within and the total energy budget of the coupled atmosphere-ice-ocean system. We analyzed data from autonomous drifting stations to investigate the seasonal evolution of the spectral albedo, transmittance, and absorptivity for different sea-ice, snow, and surface conditions measured during the MOSAiC expedition in 2019–2020. The spatial variability of these properties was small during spring and increased strongly after melt onset on May 26, 2020, when liquid water content on the surface increased, largely accounting for the enhanced variability. The temporal evolution of surface albedo and sea-ice transmittance was mostly event-driven, thus containing episodic elements. Melt ponds reduced the local surface albedo by 31%–45%. Over the melting season, single ponding events increased the energy deposition of the sea ice by 35% compared to adjacent bare ice. Thus, single melt ponds may impact the summer energy budget as much as seasonal evolution over 1 month. Absorptivity and transmittance showed strong temporal and spatial variabilities independently of surface conditions, possibly due to the different internal sea-ice properties and under-ice biological processes. The differences in seasonal evolution shown for different sea-ice conditions strongly impacted the partitioning of shortwave solar radiation. This study shows that the formation and development of melt ponds, in reducing albedo by a third of bare ice sites, can notably increase the total summer heat deposition. The vastly different seasonal evolutions, different sea-ice conditions, and timing and duration of ponding events need to be considered when comparing local in-situ observations with large-scale satellite remote sensing datasets, which we suggest can help to improve numerical models.

Sustainable, low-cost, high-contrast electrochromic displays via host–guest interactions

Electrochromic (EC) displays with electronically regulating the transmittance of solar radiation offer the opportunity to increase the energy efficiency of the building and electronic products and improve the comfort and lifestyle of people. Despite the unique merit and vast application potential of EC technologies, long-awaited EC windows and related visual content displays have not been fully commercialized due to unsatisfactory production cost, durability, color, and complex fabrication processes. Here we develop a unique EC strategy and system based on the natural host and guest interactions to address the above issues. A completely reusable and sustainable EC device has been fabricated with potential advantages of extremely low cost, ideal user-/environment friendly property, and excellent optical modulation, which is benefited from the extracted biomass EC materials and reusable transparent electrodes involved in the system. The as-prepared EC window and nonemissive transparent display also show comprehensively excellent properties: high transmittance change (>85%), broad spectra modulation covering Ultraviolet (UV), Visible (Vis) to Infrared (IR) ranges, high durability (no attenuation under UV radiation for more than 1.5 mo), low open voltage (0.9 V), excellent reusability (>1,200 cycles) of the device's key components and reversibility (>4,000 cycles) with a large transmittance change, and pleasant multicolor. It is anticipated that unconventional exploration and design principles of dynamic host-guest interactions can provide unique insight into different energy-saving and sustainable optoelectronic applications.

Modelling runoff components and hydrological processes in glaciated catchments of the inner Tien-Shan, Kyrgyzstan

Accurately quantifying runoff sources and understanding hydrological processes in glaciated mountain basins is essential for effective water resource management in the face of climate change. This study aimed to determine the contributions from various runoff sources in glaciated basins within the inner Tien-Shan mountains of Kyrgyzstan by utilizing integrated land surface, glacier energy-mass balance, and river routing models. To account for local topographic influences on solar radiation and cloud transmissivity processes, gridded meteorological forcing data were downscaled. The integrated models were then evaluated against observed discharge, glacier mass balance, and snow water equivalent, with a focus on the Kara-Batkak glacier reference site. Shortwave radiation correction was particularly important for improving the accuracy of model simulations. The results indicate that the peak glacier melt contribution occurs in July and August, with some basins reaching up to 54%. On an annual basis, the average contribution from glaciers across the basins was found to be 19%, while the ratios of snowmelt and rainfall were 58% and 23%, respectively. This study highlights the utility of integrated modelling approaches in understanding and quantifying runoff components in data-scarce high mountain regions. The incorporation of observed glacier data proved to be crucial for accurately representing hydrological processes under current climatic conditions. These findings underscore the significance of considering glacier dynamics and their influence on water resources to inform effective water management strategies in glaciated mountain basins.

INFLUENCE OF ATMOSPHERIC AEROSOLS ON THE AMOUNT OF SOLAR ENERGY REACHING THE EARTH’S SURFACE IN THE SOUTHERN PART OF WARSAW

The efficiency of photovoltaic installations depends on a number of factors. Aerosols cansignificantly influence the available resources of solar energy and thus the effectiveness of solarpanel performance. The work was an attempt to assess the influence of atmospheric aerosols onthe transmission of solar radiation in a selected region of Warsaw. The results of measurementsof specific meteorological elements and the concentration of contaminants come from themeteorological station of the Warsaw University of Life Sciences in the years 2014-2019. Theanalysis of correlation and the MLP model path were used to carry out the analysis. The obtainedresults and relationships show that there is an influence of air contaminant concentrations onthe intensity of solar radiation and insolation. High variability of the given parameters was alsorevealed, depending on the range of horizontal visibility as well as relative air humidity. The valueof the correlation coefficient r=0.80 and comparison of the intensity of measured and predictedsolar radiation of the analysed parameters make it possible to claim that the developed MLP modelfacilitates good prediction of the intensity of solar radiation based on the implemented inputdata. The analysis of the sensitivity of the model revealed that the air temperature has the greatestinfluence on the value of solar radiation intensity, and as far as air contaminants are concerned, theconcentration of particulate matter PM10 has a greatest influence on lowering its value.

A comprehensive analysis of environmental factors affecting solar cells: Dust accumulation, ambient temperature, and humidity

This paper aims to investigate the impact of environmental factors on solar cells, focusing on dust accumulation, ambient temperature, and humidity. The utilization of solar cells as a renewable source of energy has garnered significant attention in recent years, with three main types of solar cells: silicon-based, thin-film, and calcium titanium ore solar cells. While each type possesses unique strengths and weaknesses, understanding the impact of environmental factors is essential for monitoring quality and assessing their performance. Dust accumulation on photovoltaic (PV) panels reduces output power by blocking solar radiation transmission, causing uneven shading and reducing heat dissipation. High temperatures also negatively impact PV system operation by reducing the operating voltage of the cells, while humidity can block or diffract sunlight, reducing the output power of the system. This paper provides an analysis of existing literature and empirical studies, aiming to provide valuable insights into improving the efficiency and durability of solar cells and contributing to the widespread adoption of this renewable energy source.

Estimation of solar radiation transmission for polycarbonate retractable swimming poolen closures

Estimation of solar radiation transmission for polycarbonate retractable swimming poolen closures

A temperature and electric field responsive flexible hybrid composite film containing CsxWO3 nanocrystals for energy efficient smart window

Smart windows, which can dynamically adjust solar radiation transmittance in accordance with people's requirements and the ambient temperatures, play an important role in solving the problem of energy consumption in buildings. However, the polymer-dispersed liquid crystals, one of the representatives of smart window, are generally only optically modulated in the visible region, but not sensitive to the near-infrared light region, which has a thermal effect. Herein, we reported a hybrid composite film with both light and heat management by introducing inorganic CsxWO3 nanocrystals into the organic PDLC system. The optical modulation effect of this film covers the solar irradiation in the range of 400–2500 nm, including visible light and invisible near-infrared light. In addition, the optical state of the film could be switched between transparent and opaque by electric field when the temperature was below the phase transition temperature (45 °C), while the film remained transparent when the temperature was above the phase transition temperature. Simultaneously, about 60% to 95% of the NIR irradiation range of 800–2500 nm can be screened under the variations of the thermal and electric fields due to the local surface plasmon resonance of the CsxWO3 nanocrystals. The thermal insulation effect demonstrated by the model house fitted with this film gives it the potential to be used in energy-efficient smart windows.

Influence of rejuvenating pruning on the potential productivity of the apple tree

The period of operation of intensive orchards is 15 years. At the age of 6-7 years, the quality of fruits decreases sharply and the frequency of fruiting increases. In order to extend the productive period of the orchard, an experiment was laid on the effect of rejuvenating pruning on the productivity of an apple tree, depending on the variety-rootstock combination. In the course of this scientific study, in the period from 2020 to 2022, results were obtained indicating the presence of the potential for productivity of apple varieties of the Kazakhstani selection Voskhod and Talgarskoe on the introduced forms B 7-35, Arm 18 and the rootstock of the Kazakhstani selection Zhetysu 5 in which the solar radiation transmittance was from 0.45% to 0.77%. On this basis, all the studied varieties are superior to the control variant. It also improved the light space inside the tree crown, which increased the number of young growth points and contributed to the awakening of reserve buds. Young growing fruits, located in the middle and central parts of the crown, are better supplied with nutrients after pruning than before pruning.

Bioinspired Antireflection Double‐Layer Coatings Design Method and Light Management to Realize Radiative Sky Cooling in Photovoltaic Module

Recent research on combining photovoltaic (PV) modules with radiative sky cooling (RSC) technology has elicited much interest. Such cross‐disciplinary technology coupling provides a feasible approach to solar cells’ nighttime applications. However, current commonly used radiative sky cooling materials’ (RSCMs) conflict with the solar light harvesting and utilizing of PV module. The spectral selectivity characteristics of the strong transmission in the solar spectrum range (0.3–1.1 μm) and the enough emissivity within the atmosphere transparency window (8–13 μm) are the essential to develop the PV module‐usable RSC coating. Herein, antireflection (AR) structure optimize method and RSC coating design method are proposed to achieve nighttime RSC capacity with high solar radiation transmission property via the RSCM selection and light management, in the visible, near‐infrared, and midinfrared wavelength range, originating from the subwavelength optical effects of bioinspired AR design. A kind of double‐layer coating consisting of the PDMS substrate layer and SiO2 close‐packed hexagonal rotating parabolic body‐bioinspired moth‐eye structure cover layer is designed in this research. The coating has 0.997 average transmissivity characteristic in solar spectrum and can lower the PV cell temperature over 10.5 K than ambient at night.

New solar radiation transmittance models of transparent envelope based on spectral splitting and their influence on building heat gain

Climate change and the energy crisis have led to increasing attention to building energy efficiency worldwide, and transparent envelopes are more critical as a weak link in building energy efficiency. However, there is a lack of quantitative research on the spectral transmittance properties of transparent envelopes. In this paper, the spectral transmittance of transparent envelopes is quantitatively studied using the controlled variable method. The transmittance calculation formula in the existing standard is modified. Firstly, five types of transparent envelopes commonly used are selected, and their transmittance to the full solar spectrum is studied to establish a transmittance model for different wavelengths. The study also focuses on the 300 nm–1100nm waveband and establishes a solar radiation transmittance benchmark model (SRTB model) based on single-pane clear glass. Secondly, the solar radiation transmittance at different wavelengths is tested by considering both the glass material and the inclination angle, and a solar radiation transmittance modified model (SRTM model) that can be modified to the SRTB model is established. Thirdly, the variation between the incident angle and transmittance is investigated, and the solar radiation transmittance-incident angle model (SRT - IA model) is developed. The results show that deviations between the fixed transmittance and SRT - IA model can reach a maximum of more than 10% for incident angles of less than 60°. Finally, the variation in radiation heat gain due to the SRT - IA model and fixed transmittance is compared in China based on typical meteorological year data. The research conclusion can provide a more precise assessment of the building heat gain from transparent envelopes and then evaluate the building energy consumption reasonably, and provide a theoretical basis for the full-spectrum utilization efficiency of solar radiation.

Intelligent optical management for energy-efficient windows driven by mechano-thermochromism

The thermochromic windows based on vanadium dioxide (VO2) can intelligently modulate the transmittance of indoor solar radiation, which is significant for reducing building energy consumption. However, conventional thermochromic windows only have the ability of single spectral modulation, continuously switching the solar spectral transmittance in response to varying ambient temperature on a window is challenging. In this work, a SiO2-VO2-PDMS-driven by mechano-thermochromism intelligent optical management system was proposed for automatic switching and continuous adjustment of the solar spectral transmittance. Compared with the single-layer VO2 film, the SiO2-VO2 double-layer thermochromic window provides a gradual refractive index change from the top with nair = 1 to the middle with around 1.5, and then to the bottom with a higher refractive index, which suppresses reflections over a wider wavelength range. The results show that the SiO2-VO2 double-layer coating with a refractive index buffer layer exhibits improved optical performance with a solar modulation ability (ΔTsol) of 18.4% and an average luminous transmittance (Tlum,avg) of 49.1%. Furthermore, the design can achieve increases in the stretch-related solar modulation ability (ΔTsol,stretch) and the stretch-related luminous transmittance (Tlum,stretch) from 18.4% to 43.8% and 49.1% to 60.5%, respectively, which is realized by the deformation of polydimethylsiloxane (PDMS). Combining elastic stretching with thermochromic windows can dynamically modulate the solar spectral transmittance to improve thermal comfort. This work provides a promising approach to improve the industrial application of VO2 thermochromic windows, contributing to the advancement of research in green buildings, window design, and automotive energy efficiency.

Analyses the Scope of Solar Radiation Transmittance and Physical Properties of Polymethyl Methacrylate/Zinc Oxide Nanocomposite Films

Films of poly (methyl methacrylate) PMMA and PMMA doped with zinc oxide nanoparticles (ZnONPs) with different amounts were created using the solution casting technique. Different amounts of zinc oxide ranging from (0.001-0.005) g in step 0.001g were investigated and added to a polymer of constant amount (0.5) g of PMMA in 15ml Tetrahydrofuran (THF). It is known that increasing the amount of ZnONPs in this technique contributes to the appearance of ZnONP peaks within the polymer. The differences in the XRD spectrum show that the nanomaterial changed the microstructure of the polymer. This was discovered using a nanoscale scanning electron microscope (SEM). SEM revealed that the PMMA polymer surface exhibit an amorphous nature with a smooth surface. Fourier Transform Infrared (FTIR) spectroscopy demonstrates that there was no chemical reaction between the PMMA polymer and ZnONPs. Spectrophotometric measurements of absorbance and transmittance in the wavelength range 200- 900 nm were used to evaluate the optical characteristics of all films. Increased amounts of ZnONPs improve the absorbance, absorption coefficient, and extinction coefficient of PMMA polymer. With increasing ZNO content, the variance in computed optical energy gap values has been interpreted, the optical energy gap dropped from 4.65 eV to 4.10 eV. The solar radiation intensity in Baghdad for the pure PMMA films and PMMA/ZnO nanocomposites was measured at a rate of 1 hour for seven days in beginning in early September 2021, from 6 A.M to 6 P.M (13 h). As can be observed, almost all films have the same ratio of intensity of transmitted radiation to intensity of sunlight for all hours and days.

Cycling durability and potentiostatic rejuvenation of electrochromic tungsten oxide thin films: Effect of silica nanoparticles in LiClO4–Propylene carbonate electrolytes

Electrochromic (EC) technology allows control of the transmission of visible light and solar radiation through thin-film devices. When applied to “smart” windows, EC technology can significantly diminish energy use for cooling and air conditioning of buildings and simultaneously provide good indoor comfort for the buildings’ occupants through reduced glare. EC “smart” windows are available on the market, but it is nevertheless important that their degradation under operating conditions be better understood and, ideally, prevented. In the present work, we investigated EC properties, voltammetric cycling durability, and potentiostatic rejuvenation of sputter-deposited WO 3 thin films immersed in LiClO 4 –propylene carbonate electrolytes containing up to 3.0 wt% of ∼7-nm-diameter SiO 2 nanoparticles. Adding about 1 wt% SiO 2 led to a significant improvement in cycling durability in the commonly used potential range of 2.0–4.0 V vs. Li/Li + . Furthermore, X-ray photoemission spectroscopy indicated that O–Si bonds were associated with enhanced durability in the presence of SiO 2 nanoparticles. • Electrochromic properties, durability, and potentiostatic rejuvenation of W oxide thin films are investigated. • The aim was to study the effect of ∼7-nm-diameter silica nanoparticles in LiClO 4 –propylene carbonate electrolytes. • Film degradation was investigated in range between 2.0 and 4.0 V vs. Li/Li + . • Adding about 1 wt% SiO 2 led to a significant improvement in cycling durability. • O–Si bonds were associated with enhanced durability in the presence of SiO 2 nanoparticles.

Swift Photochromic Smart Window Based on Plasmonic Yolk‐Shell Nanophosphors

AbstractHerein, the fabrication of eccentric Ag@Void@Y2SiO5:Pr3+ plasmonic yolk‐shell nanophosphors (PYSNPs) with high up‐conversion efficiency, and their incorporation on photochromic WO3 layers, is demonstrated to fabricate photochromic smart windows with high coloration contrast and swift color change. The up‐conversion efficiency of the Pr3+ ion‐doped Y2SiO5 (Y2SiO5:Pr3+) nanoshells is enhanced by about 50% through the incorporation of carefully designed plasmonic Ag cores placed inside their hollow cavities. Introduction of these geometry‐optimized plasmonic nanophosphors at the surface of photochromic WO3 films results in about 24‐fold and tenfold enhancements of their coloration rate and kinetic constant, respectively. The strategy adopted for designing and fabricating the Ag@Void@Y2SiO5:Pr3+ PYSNPs and their subsequent incorporation in conventional photochromic films offers an exciting approach for fabricating photochromic smart windows with dynamically controlled transmission of solar radiation, which is a promising technology for reducing energy consumption associated with heating, ventilation, and air‐conditioning of buildings.

STMRT: A simple tree canopy radiative transfer model for outdoor mean radiant temperature

Tree canopy shading can significantly decrease the outdoor mean radiant temperature (MRT). However, canopy radiative transfer is quite complex, making it challenging to evaluate the MRT under a tree canopy. In this study, a simple tree canopy radiative transfer model (STMRT) was developed to determine the MRT under a tree canopy. In STMRT, the direct and diffuse solar radiation transfers are calculated based on the leaf inclination angle distribution, and the longwave radiation emitted from a canopy is evaluated based on the simplification that the canopy surface temperature is the same as the surrounding air temperature. The STMRT's accuracy was evaluated by measurement and compared to that of 4SAIL. The results demonstrate that the MRT differences (ΔMRT) in STMRT are typically less than 2.3 °C; in Shanghai, China, ΔMRT caused by the differences in direct solar radiation transmissivity between STMRT and 4SAIL are less than 2.0 °C, unless the leaf area index is less than 2 and the solar zenith angle is greater than 70°. According to STMRT, it is found that ΔMRT generated by the leaf inclination angle variances across various tree species can reach 9.5 °C; ΔMRT caused by a uniform distribution simplification for leaf inclination angle can reach 5.7 °C. STMRT will help plan the outdoor thermal environment by evaluating the MRT under tree canopies.

Modeling Solar Radiation Transmission by Aerosol Layers in the Lower Stratosphere in Climatic Chambers

Modeling Solar Radiation Transmission by Aerosol Layers in the Lower Stratosphere in Climatic Chambers

Photocycloaddition as a Tool for Modulation of the Lower Critical Solution Temperature in a Molecular π‐System to Control Transmission of Solar Radiation

AbstractDiels–Alder photocycloaddition, a well‐known textbook reaction, has not been explored in materials chemistry. Herein we describe how this classical photochemistry can be used to modulate the lower critical solution temperature (LCST) of a molecular π‐system, which can further be exploited for the controlled transmission of solar radiation for the management of indoor heat and light. An amphiphilic anthracene derivative 9‐PA‐1 exhibited LCST behavior at 27–32 °C with a reversible transition from a transparent to an opaque phase in water (1–5 mM). Irradiation of a toluene solution of 9‐PA‐1 with 365 nm light resulted in a [4+2] photocycloadduct 9‐PA‐2, which exhibited a modulated LCST behavior at 25–27 °C, at a concentration as low as 6 μM. The photocycloaddition of 9‐PA‐1 was significantly retarded in water, making it a stable candidate for the design of sustainable smart windows. We also demonstrated 100 cm2 smart window prototypes (ΔTlum 82 %, ΔTIR 68 %, ΔTsol 73 %) with more than 1000 cycles of stable operation.

Photocycloaddition as a Tool for Modulation of the Lower Critical Solution Temperature in a Molecular π-System to Control Transmission of Solar Radiation.

Diels-Alder photocycloaddition, a well-known textbook reaction, has not been explored in materials chemistry. Herein we describe how this classical photochemistry can be used to modulate the lower critical solution temperature (LCST) of a molecular π-system, which can further be exploited for the controlled transmission of solar radiation for the management of indoor heat and light. An amphiphilic anthracene derivative 9-PA-1 exhibited LCST behavior at 27-32 °C with a reversible transition from a transparent to an opaque phase in water (1-5 mM). Irradiation of a toluene solution of 9-PA-1 with 365 nm light resulted in a [4+2] photocycloadduct 9-PA-2, which exhibited a modulated LCST behavior at 25-27 °C, at a concentration as low as 6 μM. The photocycloaddition of 9-PA-1 was significantly retarded in water, making it a stable candidate for the design of sustainable smart windows. We also demonstrated 100 cm2 smart window prototypes (ΔTlum 82 %, ΔTIR 68 %, ΔTsol 73 %) with more than 1000 cycles of stable operation.

Urban greenhouse covering materials: Assessing environmental impacts and crop yields effects

Solar radiation transmissivity in greenhouses is a key property largely determined by covering materials. This study compared tomato crop yields and their environmental performance of a polycarbonate rooftop greenhouse with alternative covering materials displaying higher solar transmissivity and lifetime performance. An integrated approach using experimental data with structural, energy modeling was used to model average lifetime crop productivities. At building functional unit (per m2·year), impacts varied between -29.0% and +24.0% compared to the current polycarbonate. Lifetime transmissivities improved up to 20.5% (4 mm-antireflective glass), leading to +46.6% of tomato yields (19.9 ± 2.2 kg/m2), and up to -33.9% of environmental impacts. Ethylene tetrafluoroethylene 60 μm-film resulted in 19.2 ± 2.3 kg tomatoes/m2 but improved environmental performance up to 41.7%. These results demonstrate the importance of employing integrated and life-cycle approaches to combine multiple trade-offs and dynamics within environmental assessments of greenhouse crops. The results are intended to contribute to improving greenhouse cultivation and sustainability.

Analysis of chromogenic materials for angular-selective smart windows with efficient use of solar energy

This paper analyzes the achievements in recent years in the development of chromogenic materials and technologies, with a special emphasis on those that would be most effective for use both in conventional smart windows with a single continuous chromogenic layer, developed since the 1990s, and in grating smart windows, the development of which began in the 2010s. The latter have some advantages in creating a comfortable indoor lighting environment, such as angle-selective limitation of the transmission of direct solar radiation while increasing the transmission of sky-scattered radiation and radiation reflected from the ground and the facades of opposing buildings. The angular selectivity of a grating smart window is ensured by alternately passing direct sunlight through thin-film gratings with alternating transmissive and chromogenic strips on two window surfaces. Among the variety of chromogenic technologies, the most promising ones for smart windows of both types were identified. Taking into account the technological features of manufacturing grating windows, the possible cost of this technology was preliminary estimated.