High Levels Of Solar Radiation Research Articles

Study of Roof and Ceiling Surface Temperatures in Coastal Area (Case Study: Pasar Bengkulu Village)

Abstract The majority of residential roofs in Pasar Bengkulu Village are constructed using corrugated iron and galvalum metal. These coastal areas often grapple with high levels of solar heat radiation. Both corrugated zinc and galvalum roofing materials are known for their high heat conductivity and excellent heat-reflecting capabilities. To combat this, solar reflectance paint is often used to reflect solar radiation heat, thereby reducing heat absorption. This research is a qualitative research with a focus on the description and analysis of measured data which aims to compare the surface temperature of the roof and ceiling before and after being coated with reflective solar paint. This research was conducted to determine the difference in roof and ceiling surface temperatures before and after the application of solar reflective paint. The results of the roof surface temperature measurements revealed that galvalum metal roofs exhibited the most significant reduction in roof surface temperature, with a decrease of 9.1°C.

Solar Driven Syngas Production Potential in Portugal

The production of synthesis gas, or syngas, from the thermochemical conversion of different carbon-based feedstocks, including biomass, is an important alternative for the conversion of waste from sources such as agroforestry or urban waste into renewable gases or fuels. The use of solar radiation as an energy source for these thermochemical processes can reduce or even eliminate their environmental impacts and increase the energy content of the resulting syngas. Portugal, with its high levels of solar radiation, has significant potential for solarized syngas production through biomass gasification. This paper analyzes the cost competitiveness of solar-driven syngas production in Portugal using different feedstocks and solar radiation levels and compares these costs to conventional gasification costs. The results show that solarized syngas production in Portugal is economically viable and has the potential to contribute to a more sustainable and low-carbon energy system.

Wildfire susceptibility mapping by incorporating damage proxy maps, differenced normalized burn Ratio, and deep learning algorithms based on sentinel-1/2 data: a case study on Maui Island, Hawaii

ABSTRACT Climate change has contributed to the recent increase in wildfire occurrences, vegetation failures, human health risks, physical damage, and economic losses. Wildfire susceptibility mapping is an essential technique for assessing areas prone to wildfires. In this study, we proposed the combination of the damage proxy map (DPM) and differenced normalized burn ratio (dNBR) method to generate a precise wildfire inventory map and used it to predict areas susceptible to wildfire. The wildfire susceptibility maps were produced using frequency ratio (FR), convolutional neural network (CNN), and long short-term memory (LSTM)-based deep learning and their performances were compared. We implemented the proposed method on Maui Island, Hawaii, where wildfires frequently occur. We started the process by generating a wildfire inventory map from 2019 to 2023 based on the DPM method applied to Sentinel-1 synthetic aperture radar (SAR) data combined with a dNBR map retrieved from Sentinel-2 data. The wildfire inventory was randomly divided into a training dataset (70%) and a testing dataset (30%). Fifteen wildfire-related factors, including topographical, meteorological, land use, environmental, and anthropological factors, were selected to predict wildfires. The wildfire-related factors were selected by conducting study literature and considering spatial correlation analysis based on the FR method, information gain ratio analysis (IGR), and multicollinearity assessment using tolerance (TOL) and variance inflation factor (VIF) metrics. The level of susceptibility of an area to wildfire is divided into five, namely very high, high, moderate, low, and very low. The FR, CNN, and LSTM produced wildfire susceptibility maps with similar patterns, significantly influenced by land use and rainfall factors. The highly susceptible areas are located on gentle slopes covered by agricultural land and unhealthy vegetation, and these areas have low rainfall intensity but receive high levels of solar radiation. Meanwhile, areas with relatively low susceptibility occur in forests with high levels of wet canopy evaporation. The prediction results were evaluated using the area under the receiver operating characteristic (ROC) curve (AUC), and the CNN performed slightly better than the FR and LSTM, with AUC values of 0.879, 0.877, and 0.870, respectively. Hence, the use of the CNN algorithm in the proposed method is appropriate, specifically for the study area. In addition, the susceptibility map provides information on susceptible areas on Maui Island, Hawaii, to increase public awareness.

The role of climatic variables on nest evolution in tanagers.

Avian nests are fundamental structures in avian reproduction and face strong selective forces. Climatic conditions are likely to have shaped the evolution of specific nest traits, but evidence is scarce at a macroevolutionary level. The Thraupidae family (commonly known as tanagers) is an ideal clade to understand the link between nest architecture and climate because it presents wide variation in nest traits. To understand whether climatic variables have played a role in the diversification of nest traits among species in this family, we measured nests from 49 species using museum collections. We observed that dome-nesting species are present in dryer and hotter environments, in line with previous findings suggesting that domed nests are a specialisation for arid conditions. We also found evidence that nests with thicker walls are present in locations with lower precipitation and that solar radiation can influence the shape of domed nests; birds tend to build shorter and narrower domes in areas with high levels of solar radiation. Open nest architecture is also potentially influenced by wind speed, with longer and deeper nests in areas characterised by strong winds. Our results support the hypothesis that different climatic variables can drive the evolution of specific aspects of nest architecture and contribute to the diversity of nest shapes we currently observe. However, climatic variables account only for a small fraction of the observed structural variation, leaving a significant portion still unexplained.

Growth and flowering of carnation cultivated in different pot colors and protected environments

Growth and flowering of carnation cultivated in different pot colors and protected environments

IMPACT OF UNSEALED SURFACE PAVEMENTS ON AIR TEMPERATURE AND HUMIDITY IN PUBLIC SPACES

Public space allows the interaction and encounter of the population without distinction of age, race or gender. The use and permanence in these places depend on the accessibility and comfort experienced by the user. Among the main aspects that determine comfort is temperature control or control of the sensation of heat conditioned by thermal radiation, environmental conditions (air temperature and humidity, wind speed, shade and shelter), and individual factors (age, health, clothing, physical activity). Pavement options affect the sensation of heat, some, such as reflective or lighter-colored pavements can help mitigate the urban heat island effect by reducing the absorption of solar radiation and lowering surface temperatures. This research focuses on the effects of thermal radiation from unsealed surface pavements on air temperature and relative humidity at different heights (5 cm, 60 cm, 90 cm, 120 cm, and 150 cm). Measurements were recorded in central public places such as squares and parks in the city of Loja (Ecuador) exposed to high levels of solar radiation. The study mainly revealed that grass and white terrazzo presented lower surface temperatures and increased the relative humidity of the air at 150 cm, refreshing the environment and contributing to the mitigation of the heat island effect.

Power Simulation of a CubeSat: Influence of Orbit, Attitude, and Thermal Control

CubeSats must endure the extreme temperature and radiation changes that are a result of the environment in orbit. The power system of CubeSats, which produces the electrical energy required to carry out the activities, is a crucial component. The photovoltaic effect, a phenomenon whose maximum power point decreases as temperature rises while the peak rises with solar radiation intensity rises, is used by the majority of satellites, including CubeSats, to convert solar radiation into electrical energy. High temperatures should be avoided since they decrease the effectiveness of this photovoltaic phenomenon, whereas high solar radiation levels are required to produce more energy. This study evaluates a simulation of a CubeSat 1U with solar panels mounted on all of its faces to examine the impact of orbit, attitude, and temperature management on power generation. The outcomes show that higher performance may be obtained by carefully choosing these factors.

Towards a More Sustainable Viticulture

Grapevines in Argentina, Chile and South Africa are grown under high levels of solar radiation. The availability of this resource is an opportunity to implement agrivoltaics as a practice for climate change mitigation. This study was conducted during 2020-2021 to: i) compare the legal framework in these countries to promote photovoltaic (PV) technology, ii) analyze the integration of PV technology with viticulture, and iii) evaluate its social acceptance. To analyze the regulatory framework, national and regional laws to promote the integration of PV technology with viticulture were evaluated. The PV technology and viticulture practices adopted were evaluated through a survey in ten vineyards located in Argentina, Chile, and South Africa. Social acceptance of PV integration with viticulture was evaluated in a participative process. The main facilitators common to the three countries are the availability of the solar resource, the scenario of legislative transformation related to the production of renewable energies, and the reduction of production costs in the long term for wine companies. Although there have been advances in the regulatory frameworks, especially in Chile and Argentina, agrivoltaics is still not mentioned. This, coupled with limited local experience of agrivoltaics in vineyards, limits communication of the potential benefits in grape, wine, and energy production.

Impact of Distributed Generation and Energy Storage on Power Quality

With electricity demand increase and the need to expand and diversify generating sources in pursuit of energy sustainability, the distributed generation (DG), from unconventional renewable sources, has been getting more and more space in the distribution system (DS). In Brazil, this DG dissemination is predominantly photovoltaic solar energy (PV) due to the characteristics and high levels of solar radiation. As this type of source depends on solar irradiation for energy conversion, the PV system is directly influenced by cloudiness, which causes part of the solar incidence to reflect in the clouds and may cause a drastic and abrupt reduction of the generated power. This phenomenon is difficult to predict, thus making PV systems an intermittent and considered supplementary source. Moreover, as it is an electronically processed generation source for power conversion and adequacy, there is the incidence of harmonic injection in the distribution network at the connection point. Due to the possible problems that DG can cause in DS, this paper presents an analysis of the impact on power quality (PQ) of a DS, considering different allocations, penetration levels, and system load. The study focus is on the Brazilian DS, so the system was adapted to the local reality through real dealership data

Turning weakness into strength - A feasibility analysis and comparison of datacenter deployment in hot and cold climates

Datacenters are major components of the Information and Communication Technologies (ICT) responsible for storing, processing and transmitting enormous amounts of data every second. The significance and importance of datacenters in the world economy can be identified from studies which report that in 2023, datacenter infrastructures consumed a total of 4 % of global electricity and contributed 3–5% of global carbon emissions, whereas between the years of 2017–2021, datacenters added $2.1 trillion to the U.S. Gross Domestic Product (GDP). A big portion of energy supplied in datacenters is consumed by the required cooling systems hence companies do not favor developments in hot climate countries. However, due to environmental and climate change concerns along with the steep increase of energy production costs in recent years made the industry look for alternatives. This work includes an in-depth feasibility and comparative study of datacenter construction and operation in hot and cold European countries and addresses the environmental impact of photovoltaics integration in the electrical supply system. The study considers cost parameters (land, operating expenses, photovoltaic system, etc.), the net present cost and levelized cost of energy which are different for each European country under investigation. Furthermore, for every country under consideration, the PV generation was simulated using the PVsyst software which includes multiple meteorological databases, whereas the feasibility analysis was simulated using the HOMER Pro software which integrates components, resources and economic calculations. An elaborate analysis of the results knocks down the common belief that datacenters have lower operational and running expenses in cold climates because of lower cooling requirements. On the contrary, this study shows that hot climates with high solar radiation levels may favor the operation of datacenters by providing 45 % higher green energy and 35 % lower CO2 emissions, whereas the cooling cost is only 5 % higher. In addition, the break-even period for the photovoltaic system in Southern European countries with hot climates is 3–4 times faster.

The Impact of Solar Radiation at Different Colombian Thermal Floors on an Adsorption Refrigeration Cycle

The process of energy transition in Colombia has sparked an exploration into appropriate geographical areas for the utilization of solar energy. The country’s rugged terrain and significant climate variability pose challenges for implementing standardized technologies uniformly across all regions. Consequently, this study aims to develop and apply a mathematical model to characterize the performance of a solar adsorption cooling system under the environmental conditions found in six distinct Colombian cities, taking into account different thermal profiles and extreme weather periods such as the El Niño and La Niña phenomena. The selected mathematical model was simulated in these cities, considering ambient temperature and solar radiation variables over a twelve-month period during these extreme weather phenomena and an additional twelve-month period representative of a typical year with minimal influence from these phenomena. The results indicated that despite a lower coefficient of performance (COP) compared to the other cities, Riohacha demonstrated a greater number of ice production days owing to its high levels of solar radiation.

Comparison between Air-Exposed and Underground Thermal Energy Storage for Solar Cooling Applications

Solar energy is one of the main alternatives for the decarbonization of the electricity sector and the reduction of the existing energy deficit in some regions of the world. However, one of its main limitations lies in its storage, since this energy source is intermittent. This paper evaluates the potential of an underground thermal energy storage tank supplied by solar thermal collectors to provide hot water for the activation of a single-effect absorption cooling system. A simulator was developed in TRNSYS 17 software. Experimentally on-site measured data of soil temperature were used in order to increase the accuracy of the simulation. The results show that the underground tank reduces thermal energy losses by 27.6% during the entire hot period compared with the air-exposed tank. The electrical energy savings due to the reduction in pumping time during the entire hot period was 639 kWh, which represents 23.6% of the electrical energy consumption of the solar collector pump. It can be concluded that using an underground thermal energy storage tank is a feasible option in areas with high levels of solar radiation, especially in areas where ambient temperature drops significantly during night hours and/or when access to electrical energy is limited.

No large effects on cognitive performance in high versus low solar green-flag WBGT conditions

Excessive solar radiation negatively affects cognitive performance. Occupational guidelines typically combine environmental components into one value, such as wet-bulb globe temperature (WBGT). Here, we evaluated cognitive performance in two similar 28.6 °C WBGT-effective (WBGTeff) that were designed differently; using high or low levels of solar radiation. Eight soldiers were exposed to a virtual-reality environment in a climate chamber set to high (900 Wm−2) or low solar radiation conditions (300 Wm−2). Soldiers walked 3 x 30 min at 5 kmh−1. Cognitive performance was evaluated using a virtual-reality scenario and a computerised test battery. There was no statistically significant effect of condition on the cognitive tasks (p > 0.05). Associations were found between mean body temperature (Tb) and visual detection (P ≤ 0.01). Differences in solar radiation with similar WBGTeff (28.6 °C) do not cause large systematic differences in cognitive performance. Certain aspects of cognitive performance (i.e. response inhibition) seem to be partly associated with Tb rather than solar radiation. Practitioner summary: Cognitive performance was evaluated in two similar WBGT conditions that were designed differently; using high or low levels of solar radiation. Differences in solar radiation with similar WBGT do not cause systematic differences in cognitive performance. Certain aspects of cognition were partly associated with mean body temperature rather than solar radiation.

Distribution characteristics and environmental effects of non-methane hydrocarbons in the East China Sea

Non-methane hydrocarbons (NMHCs) are important reactive compounds in the atmosphere which are crucial to the formation of ozone (O3) and secondary organic aerosol (SOA). In this study, the distribution characteristics, sea-to-air fluxes, and environmental effects of NMHCs were investigated in the East China Sea during spring and autumn. Affected by abundant nutrients and dissolved organic matter in the coastal area, NMHCs concentrations inshore were higher than those offshore. The mean concentrations of ethane, ethene, propane, propene, and isoprene were 5.1, 3.8, 6.0, 2.3, and 4.0 times higher in spring than autumn, respectively. In spring, the higher isoprene concentrations might have been due to the higher phytoplankton biomass and outbreak of dinoflagellates, while elevated concentrations of other NMHCs were primarily due to photochemical processes associated with high level of solar radiation. Influenced by terrestrial input and atmospheric chemical reactions, atmospheric concentrations of NMHCs were significantly higher in autumn than in spring. The mean concentrations of ethane, ethene, propane, propene, and isoprene were 221 ± 92.4, 182 ± 112, 198 ± 184, 46.4 ± 25.4, and 7.0 ± 2.9 pptv in spring, and 1090 ± 353, 655 ± 519, 701 ± 329, 476 ± 388, and 35.0 ± 23.2 pptv in autumn, respectively. The mean sea-to-air fluxes of the five NMHCs were 132 ± 126, 658 ± 591, 123 ± 128, 93.4 ± 89.0, and 120 ± 98.6 nmol m−2 d−1 in spring and 31.1 ± 25.9, 352 ± 212, 36.5 ± 40.5, 71.2 ± 43.9, and 78.6 ± 64.8 nmol m−2 d−1 in autumn, respectively. In addition, according to the environmental effects of NMHCs, alkenes exhibited higher atmospheric chemical reactivity and were the major contributors to O3 and SOA formation.

The influence of meteorological factors on COVID-19 spread in Italy during the first and second wave

The relation between meteorological factors and COVID-19 spread remains uncertain, particularly with regard to the role of temperature, relative humidity and solar ultraviolet (UV) radiation. To assess this relation, we investigated disease spread within Italy during 2020. The pandemic had a large and early impact in Italy, and during 2020 the effects of vaccination and viral variants had not yet complicated the dynamics. We used non-linear, spline-based Poisson regression of modeled temperature, UV and relative humidity, adjusting for mobility patterns and additional confounders, to estimate daily rates of COVID-19 new cases, hospital and intensive care unit admissions, and deaths during the two waves of the pandemic in Italy during 2020. We found little association between relative humidity and COVID-19 endpoints in both waves, whereas UV radiation above 40 kJ/m2 showed a weak inverse association with hospital and ICU admissions in the first wave, and a stronger relation with all COVID-19 endpoints in the second wave. Temperature above 283 K (10 °C/50 °F) showed a strong non-linear negative relation with COVID-19 endpoints, with inconsistent relations below this cutpoint in the two waves. Given the biological plausibility of a relation between temperature and COVID-19, these data add support to the proposition that temperature above 283 K, and possibly high levels of solar UV radiation, reduced COVID-19 spread.

Wind and solar energy potential in Herkalou and Lake Assal locations, Djibouti

The absence of meteorological data to identify the energy resources and the available energy potential represented a major obstacle in some areas in Djibouti. To solve this data problem, in this paper, wind and solar potential were assessed by collecting daily and monthly wind and solar data for the period from 1 January to 31 December 2020, for Herkalou and Lake Assal site. This study highlights that the wind resources in the Lake Assal location are falling into class 7 with high wind speed value of 16 m.s<sup>-1</sup> and the wind energy reaching1700 kWh/m<sup>2</sup> at 100 m height above ground level. While the Herkalou site shows a lower potential with value of 7.5 m.s<sup>-1 </sup>and 160 kWh/m<sup>2</sup>. The solar potential shows a similar distribution and a constantly high level of solar radiation throughout the year, with the monthly maximum global radiation peaks of around 900 W/m² between 11.00 and 14.00 pm for both sites. The highest monthly average of global solar irradiation values was 5.29 kWh/m<sup>2</sup> day<sup>-1 </sup>and 6.90 kWh/m<sup>2</sup> day<sup>-1 </sup>in March for Herkalou and Lake Assal, respectively. Results obtained in this study are favorable to deploying the solar and wind technologies for the studied sites.

Determination of the appropriate zone on dam surface for floating photovoltaic system installation using RS and GISc technologies

This study aims to reveal suitable places where floating photovoltaic-solar power plants (FPV-SPPs) can be installed on the dam surface using the possibilities of remote sensing (RS) and geographical information science (GISc) technologies. Past satellite images from Landsat and Sentinel platforms allow researchers to analyse shoreline changes in the dam surface. Shoreline extraction is a crucial process for the FPV-SPP to stay afloat despite external constraints. In this study, changes in dam water levels were determined by classifying 20-year satellite images and analysing a 32-year global surface water dynamics dataset. The water surface area was calculated as 1,562.40 ha using the random forest (RF) algorithm and the normalized differences water index (NDWI) on Google Earth Engine (GEE) cloud platform. In addition, solar analysis was carried out with GISc using annual solar radiation maps shuttle radar topography mission (SRTM) data, which directly affects the energy production of FPV-SPPs. It has been calculated that the solar radiation on the water surface varies between 1,554 kWh/m2-year and 1,875 kWh/m2-year. These calculated values were divided into five different classes, and it was observed that 88.5% of the dam surface had a very high level of solar radiation compared to other areas. Higher efficiency will be obtained from the FPV-SPP to be installed in this region compared to the systems to be installed in other regions. It has been observed that the radiation values in other parts of the water surface are lower due to topographic shading. These analyses revealed energy zones with high production potential, thereby easing the decision-making process for investors planning to establish FPV-SPPs.

Daylight oriented optimization of photovoltaic integrated skylights for railway station waiting hall represented large space buildings in China

Photovoltaic Integrated Skylights (SIPVs) have been widely used due to their unique synergistic benefits of shading and power generation. Their variable shading and light transmission properties upon varying lighting climates could aggravate the complexity of the daylighting conditions, especially when applied to large space public building skylights. In this study, Chinese cities Lhasa and Beijing were selected as representative cities for semi-transparent photovoltaic (STPV) skylight surveys corresponding to high and moderate solar radiation levels. Railway station waiting halls as the typical large space building, together with SIPVs in varying distribution modes and skylight-to-roof ratios (SRRs) have been modeled and examined. By the aid of dynamic daylighting indicator metrics and DAYSIM simulation tool, this work verified critical roles that SIPV SRRs play in indoor daylighting qualities, for both centralized and uniserial array skylight distributions. As a result, 30 % ∼ 35 % and 23 % ∼ 30 % were determined as the best value ranges for centralized SIPVs, while 16.52 % ∼ 19.27 % and 11.01 % ∼ 19.27 % were confirmed as the best value range for uniserial array distributed SIPVs, for Beijing and Lhasa accordingly. For the first time SIPV SRR based design recommendations considering both typical distribution modes had been concluded for railway station represented large space buildings, for Lhasa and Beijing represented daylighting climates or similarities. The research outcomes can assist more effective SIPV designs and daylight optimizations for such large space type public buildings.

Morphology of coat and skin of small ruminants reared in the Brazilian semi-arid region

The structure of the coat and integument of small ruminants reared in semi-arid regions have valuable characteristics that favor their adaptation to the region. The objective of this study was to evaluate the structural characteristics of the coat and integument and sweating capacity of goats and sheep in the Brazilian semi-arid region, using 20 animals, 10 of each breed, 5 males and 5 females of each species, grouped in a completely randomized design in a 2 x 2 factorial scheme (2 species and 2 genders) with 5 replicates. The animals were already being kept under the influence of high temperatures and levels of direct solar radiation before the day of the collections. At the time of the evaluations, ambient temperature was high, with low relative humidity. The pattern of epidermal thickness and sweat glands per body region was superior in sheep (P < 0.05), and the number of hair follicles and sweat rate were similar (P > 0.05) between the species. There was no difference (P > 0.05) in the evaluated characteristics between the genders, showing that they are not influenced by hormones. The morphology of the coat and skin of these animals showed a superiority of goats compared to sheep.

Factors affecting survival and dispersal of the comma butterfly in a high mountain deciduous forest habitat

Population and community dynamics of butterflies are relatively well known in Europe thanks to citizen science and academic efforts to cover large spatio–temporal scales. However, there are still gaps of knowledge about which life–history traits have a large influence on the dynamics of particular species and the ecological factors that influence those traits. We conducted a capture–recapture demographic study on the comma butterfly Polygonia c–album in a high mountain deciduous forest. We estimated daily survival in breeding adults caught while foraging on thistles and we calculated the probability of dispersal between two close sites. Thistle growth was enhanced by nitrification in cattle grazing in the study area. Local survival was higher for males (0.920, 95 % CI: 0.851–0.959) than for females (0.869, 95 % CI: 0.799–0.917). Short–range dispersal mostly occurred in absence of wind. Light winds and high levels of solar radiation likely enhanced foraging activity. In contrast with findings in most butterfly demographic studies, recapture rates were significantly higher in females than in males, likely due to the latter moving each afternoon to establish territories along sunny forest edges away from the foraging habitat. Further demographic studies are needed to assess the effects of climate stochasticity and habitat transformation caused by changes in extensive cattle grazing on the population dynamics of the comma butterfly.