Estimation of Methods of Calculation of Values of Total Solar Radiation for Different Time Intervals

2021 ◽  
pp. 89-98
Author(s):  
Yuri Y. Tkachenko ◽  
Vladimir V. Latun ◽  
Valeriy I. Denisov
Keyword(s):  
Solar Radiation ◽  
Calculated Data ◽  
Time Interval ◽  
Total Solar Radiation ◽  
Total Radiation ◽  
Calculation Methods ◽  
Time Intervals ◽  
High Dust Content ◽  
Former Ussr ◽  
Small Cloud

The article presents the results of evaluation of a number of methods for calculating total, scattered and direct radiation. The methods were tested on actinometric data of eight stations of the former USSR, located in different climatic and latitudinal zones, in order to clarify the spatial boundaries of their application and the time interval for which it is possible to carry out calculations with an error of not more than 10 %. It is established that the accuracy of calculations is influenced by the location of the station in relation to the seas and lakes. In addition, a number of methods do not take into account the tier and shape of the cloud, so at the same amount of cloud observed different amounts of total radiation, which in turn leads to errors in the calculation of the amounts of radiation. For stations with high atmospheric transparency and low air humidity, the calculation methods provide understated data compared to full-scale ones. For stations with high dust content of the surface layer of the atmosphere, the calculated data are overstated. For marine and lake stations, overestimation of the calculated data is caused by increased humidity throughout the year and as a result, even with a small cloud cover, incoming solar radiation is significantly weakened by water vapor. The considered calculation methods can be used to calculate monthly amounts of total radiation with an accuracy of 10-12 %. Calculation for shorter time intervals leads to an increase in calculation errors. Using the method of calculating the total radiation components gives an error in the calculation of monthly amounts from 10 to 30 %, depending on the latitude. Performing calculations using this method for time intervals less than a month leads to a sharp increase in the size of errors.

scholarly journals Evaluation of Optimal Occasional Tilt on Photovoltaic Power Plant Energy Efficiency and Land Use Requirements, Iran

2021 ◽  
Vol 13 (18) ◽  
pp. 10213
Author(s):  
Amirhossein Fathi ◽  
Masoomeh Bararzadeh Ledari ◽  
Yadollah Saboohi
Keyword(s):  
Power Plant ◽  
Solar Radiation ◽  
Solar Energy ◽  
Orientation Angle ◽  
Optimum Operating ◽  
Time Interval ◽  
Time Intervals ◽  
Optimum Time ◽  
Equal Time ◽  
Geographical Regions

The paper studies the optimum panel horizontal orientation angle toward the Sun and the optimum time interval of the panel’s movement. The optimum time intervals or panel movement can change the rate of input energy to the panel surface in Iran. For this purpose, a neural network has been trained to estimate the intensity of solar radiation in Iran. After model validation, the intensity of solar radiation has been estimated by selecting adequate geographical regions. Based on the intensity of sunlight, Iran has been divided into ten regions. In these regions, 40 cities have been randomly selected to study the effect of the panel’s angle variations within appropriate time intervals, as well as equal time intervals. The results show that the choice of the mounting system with the possibility of five angles’ implementation can increase the amount of solar energy between 3.9% and 7.4%. Compared to this number of angles at the equal time intervals, the amount of incoming solar energy has increased by 3% to 7%. In the first and second cases, the area of the power plant increases by about 12% to 24% compared to the yearly optimum tilt angle. Moreover, the amount of radiation incoming to the panel with the optimum operating angle is in alignment with the results of PVsyst software.

Evaluation of Different Radiation and Albedo Models for the Prediction of Solar Radiation Incident on Tilted Surfaces, for Four European Locations

1996 ◽  
Vol 118 (3) ◽  
pp. 183-189 ◽  
Author(s):  
B. E. Psiloglou ◽  
C. A. Balaras ◽  
M. Santamouris ◽  
D. N. Asimakopoulos
Keyword(s):  
Solar Radiation ◽  
Diffuse Radiation ◽  
Vertical Surface ◽  
Mean Bias Error ◽  
Bias Error ◽  
Total Solar Radiation ◽  
Total Radiation ◽  
Radiation Incident ◽  
Tilted Surface ◽  
Significant Difference

The diffuse radiation incident on an inclined surface is composed of both the sky diffuse radiation and the ground-reflected radiation. Depending on the model used to calculate the sky diffuse radiation and the estimated albedo value, it is possible to introduce a significant error in the prediction of the total radiation incident on a tilted surface. Twelve sky diffuse submodels associated with four different albedo submodels are used to estimate the total radiation on the tilted surface from data on the horizontal plane. The predicted total solar radiation values are compared with measured data on a south facing vertical surface, from four representative south and north European locations. Root mean square error, mean bias error, and a t-test are used to determine the intrinsic performance of each combination of diffuse tilt and albedo submodel. Accordingly, the various model combinations do not exhibit a statistically significant difference between measured and calculated values.

Developing and Evaluation of Various Correlations for Diffuse Solar Radiation for Urla (Izmir, Turkey)

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Orhan Ekren
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Tracking System ◽  
Diffuse Radiation ◽  
Energy System ◽  
Solar Irradiation ◽  
Total Solar Radiation ◽  
Total Radiation ◽  
Diffuse Solar Radiation ◽  
Tilted Surface

Characteristics of site-specific solar irradiation is required to optimize a solar energy system. If no tracking system is used, the amount of electricity or heat produced by solar energy depends on the total solar radiation on a tilted surface. Although pyranometer measures direct plus diffuse solar radiation on a horizontal surface, there are many locations where diffuse radiation is not measured. Also, diffuse radiation is necessary to determine the total radiation on a tilted surface. Therefore, in this study, new correlations for diffuse solar radiation is proposed as a function of atmospheric parameters for Urla (Izmir, Turkey). After applying the statistical procedure on the measured data, seven new correlations are proposed for the ratio of hourly average diffuse and total radiation. Also, the ratio of monthly average daily diffuse and total radiation for this region is proposed.

scholarly journals On the parameterization of phytoplankton primary production in water ecosystem models

2021 ◽  
Vol 2131 (3) ◽  
pp. 032079
Author(s):  
S Golosov ◽  
I Zverev ◽  
A Terzhevik ◽  
N Palshin ◽  
G Zdorovennova ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Trophic Status ◽  
Calculated Data ◽  
Total Solar Radiation ◽  
Atmospheric Conditions ◽  
Ecosystem Models ◽  
Phytoplankton Primary Production ◽  
Lake Ecosystems ◽  
Water Ecosystem ◽  
Best Fit

Abstract Parametrization of the formation of organic matter in ecological models is traditionally carried out by using the dependence of the Michaelis – Menten – Monod type [Monod, 1942], which describes the growth rate of algal biomass depending on the factor limiting their development. One of the biggest drawbacks of these dependences is the presence of empirical parameters in them, which in a complex way depend on environmental factors and are an individual characteristic of various types of algae. These parameters in the models actually become fitting coefficients that provide the best fit between observational data and modeling results, which does not allow for effective diagnostics and forecasting of the state of aquatic ecosystems. In this work, on the basis of dimensional analysis, a parametrization was obtained that describes the photosynthesis of algae depending on the parameters relatively easily measured in natural conditions - total solar radiation, phytoplankton biomass, and water transparency. Parametrization has been verified according to observations on more than 30 different types of lakes located in different regions of the world. The calculated data are in satisfactory agreement with the data of field observations, both qualitatively and quantitatively. Discrepancies in field and calculated data may be due to the fact that the species composition of algae in lakes of different trophic status is not taken into account, which can lead to errors in assessing the efficiency of using solar radiation. Discrepancies may also be related to the total solar radiation, rather than photosynthetic active radiation, which varies in different geographic and atmospheric conditions. The proposed parametrization can be used in the development of mathematical models of lake ecosystems, as well as to determine the trophic status of poorly studied water bodies.

scholarly journals Solar Radiation Potential at Four Sites of Nepal

1970 ◽  
Vol 8 (3) ◽  
pp. 189-197 ◽  
Author(s):  
Khem N Pondyal ◽  
Binod K Bhattarai ◽  
Balkrishna Sapkota ◽  
Berit Kjeldstad
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Diurnal Variation ◽  
Sea Level ◽  
Air Pollutants ◽  
Calculated Data ◽  
Horizontal Surface ◽  
Total Solar Radiation ◽  
Annual Average ◽  
Clear Sky

The intensity of solar radiation available at the horizontal surface are measured by a CMP6 Pyranometer in Biratnagar (26.45°N, 87.27°E), Pokhara (28.22°N, 83.32°E), Kathmandu (27.72°N, 85.32°E ) and Lukla (26.69°N,86.73°E), which are 72m, 800m, 1350m, and 2850m, above from the sea level. This paper compares the seasonal and altitude variations of total solar radiation measured at above mentioned sites. The maximum total solar radiation of about 704.51 W/m2, 815.97 W/m2 777.27 W/m2 and 914.03 W/m2, are observed in Biratnagar, Pokhara, Kathmandu, and Lukla respectively. Solar radiation available in any location is affected by topography and pollution. It is found that the more solar energy is available during spring than in summer in Lukla. The solar radiation is observed higher in Pokhara than in Kathmandu. It might be due to absorption of solar energy by air pollutants which are higher in Kathmandu as compared to Pokhara.In addition we also discussed the diurnal variation of measured and calculated data of solar radiation on clear sky day. The annual average solar energy measuring 4.95, 5.44, 5.19 and 4.61 kWh/m2/day is found in Biratnagar, Pokhara Kathmandu and Lukla respectively. DOI: http://dx.doi.org/10.3126/jie.v8i3.5944 JIE 2011; 8(3): 189-197

scholarly journals Long-term variations in solar radiation, diffuse radiation, and diffuse radiation fraction caused by aerosols in China during 1961–2016

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0250376
Author(s):  
Hongfei Xie ◽  
Junfang Zhao ◽  
Kaili Wang ◽  
Huiwen Peng
Keyword(s):  
Solar Radiation ◽  
Atmospheric Aerosols ◽  
Terrestrial Ecosystem ◽  
Diffuse Radiation ◽  
Total Solar Radiation ◽  
Total Radiation ◽  
Negative Effects ◽  
Positive Effects ◽  
Sunshine Hours ◽  
The Impact

The effects of atmospheric aerosols on the terrestrial climate system are more regional than those of greenhouse gases, which are more global. Thus, it is necessary to examine the typical regional effects of how aerosols affect solar radiation in order to develop a more comprehensive understanding. In this study, we used global AErosol RObotic NETwork (AERONET) data and robust radiation observational evidence to investigate the impact of aerosols on total radiation, diffuse radiation, and the diffuse radiation fraction in China from 1961 to 2016. Our results showed that there were different temporal changes in the aerosol optical depth (AOD), total solar radiation, diffuse radiation and diffuse radiation fraction over the past 56 years. Specifically, the 550 nm AOD from 2005 to 2016 decreased significantly, with annual average AOD of 0.51. Meanwhile, the average total solar radiation reduced by 2.48%, while there was a slight increase in average diffuse radiation at a rate of 3.10 MJ·m-2·yr-1. Moreover, the spatial heterogeneities of AOD, total radiation, diffuse radiation, and the diffuse radiation fraction in China were significant. Aerosol particle emissions in the developed eastern and southern regions of China were more severe than those in the western regions, resulting in higher total radiation and diffuse radiation in the western plateau than in the eastern plain. In addition, aerosols were found to have negative effects on total radiation and sunshine hours, and positive effects on diffuse radiation and diffuse radiation fraction. Further, the diffuse radiation fraction was negatively correlated with sunshine hours. However, there was a positive correlation between AOD and sunshine hours. These results could be used to assess the impacts of climate change on terrestrial ecosystem productivity and carbon budgets.

scholarly journals Solar Energy Resources of Nakhchivan

2021 ◽  
Vol 7 (9) ◽  
pp. 69-78
Author(s):  
S. Novruzova
Keyword(s):  
Renewable Energy ◽  
Solar Radiation ◽  
Solar Energy ◽  
Energy Resource ◽  
Horizontal Surface ◽  
Energy Resources ◽  
Total Solar Radiation ◽  
Total Radiation ◽  
The Republic ◽  
Autonomous Republic

The presented article examines the issues of energy security of the Nakhchivan Autonomous Republic, which is an integral part of the Republic of Azerbaijan, and the use of renewable energy in its provision. For this purpose, the solar energy resources of the Autonomous Republic were studied. The study used theoretical, computational, observational and comparative analysis methods to estimate solar energy as a renewable energy resource. The main source for assessing the potential of solar energy of the Autonomous Republic — experimental and observation materials of the USSR Hydrometeorological Committee on the Republic of Azerbaijan and NAR for 1960–1980, the results of researches of the Institute of Geography of the Azerbaijan National Academy of Sciences for 1936–1950, Nakhchivan AR experimental-observation materials of the Hydrometeorological Center for 1995–2015, static indicators of Nakhchivan Solar Power Plant for 2016–2017, as well as the results of theoretical and computational research were used. As a result of the study, it was determined that the annual value of total radiation (Q) in the horizontal area was 7541 and 6204 MC/m2, respectively, in the clear and medium cloudy sky. At the same time, the average annual transparency coefficient was 0.8229, 0.811 in winter and 0.897 in summer. The annual value of total radiation (Q) of the horizontal field in the territory of the NAR is higher than in other regions of the country, and the coefficient of transparency of the atmosphere is higher than in other regions, too. At the same time, the duration of solar radiation in the NAR is high and is 2792 hours. Formulas have been proposed to calculate the value of solar radiation falling on a horizontal surface on the basis of many years of experimental and observational materials. Using these calculation formulas, it is possible to calculate the total solar radiation on the horizontal surface for any area of the NAR.

Interaction of triapenthenol and environmental factors on the growth and flower bud formation of Gardenia jasminoides Ellis

1998 ◽  
Vol 78 (4) ◽  
pp. 635-640 ◽  
Author(s):  
A. Kamoutsis ◽  
A. Chronopoulou-Sereli ◽  
C. Holevas
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Growth Period ◽  
Maximum Temperature ◽  
Total Solar Radiation ◽  
Total Radiation ◽  
Flower Buds ◽  
Flower Bud ◽  
Gardenia Jasminoides ◽  
Gardenia Jasminoides Ellis

The interaction effects between total solar radiation, air temperature and relative humidity with different concentrations of the plant growth regulator triapenthenol (Baronet) on the vegetative growth and the formation of flower buds of potted gardenia (Gardenia jasminoides Ellis) plants were studied in glasshouse experiments.Triapenthenol was applied as a soil drench at concentrations of 0, 70, 140 and 280 mg L–1 to plants under each of three radiation levels of about 250 (P1), 90 (P2) and 25 (P3) Wm−2. It was established that the maximum temperature was the most critical environmental factor to plant development at all radiation levels. Lengths of new lateral shoots after pinching and the number of flower buds/plant were significantly reduced when radiation was reduced and triapenthenol concentrations increased. The interaction between total radiation and triapenthenol concentration significantly affected the number of flower buds/plant. An increase in triapenthenol concentration and a reduction of total radiation caused increased wrinkling of the leaves.In the unshaded plot (P1), the 140 mg L−1 triapenthenol concentration produced high-quality plants that were shorter than the untreated ones with more flower buds/plant during the growth period. In the moderately shaded plot (P2), the best market-quality plants were those treated with 70 mg L−1 triapenthenol. Key words: Gardenia jasminoides, temperature, total solar radiation, triapenthenol, relative humidity

scholarly journals Database of hourly and daily sums of total radiation at Russian antarctic stations: analysis of changes in total radiation for the entire period of observations in Antarctica

2021 ◽  
Vol 67 (3) ◽  
pp. 249-260
Author(s):  
E. E. Sibir ◽  
V. F. Radionov ◽  
E. N. Rusina
Keyword(s):  
Solar Radiation ◽  
Total Solar Radiation ◽  
Polar Regions ◽  
Special Role ◽  
Total Radiation ◽  
Radiation Regime ◽  
Vostok Station ◽  
Forming Characteristics ◽  
State Registration ◽  
The Antarctic

Given the significant changes in the climate on the planet as a whole, databases and archives of data on the main climate-forming characteristics of the atmosphere, collected over long periods of time in various regions of the globe and, in particular, in the polar regions, acquire a special role. Total solar radiation is one of the most important parameters affecting the energy balance of the Earth-atmosphere system. We have created a database (DB) of hourly and daily sums of total radiation (Q) at the Russian Antarctic stations, designed to study the radiation regime of the Antarctic, from the beginning of actinometric observations to 2019. The information presented in the database was collected at five Antarctic stations — Bellingshausen, Vostok Mirny, Novolazarevskaya and Progress. The database has undergone a state registration procedure and is registered under No. 2020621401. The article gives a description of the structure of the DB and presents detailed information for each station. To provide an example of how database information can be used, characteristics of the total radiation in different parts of the Antarctic continent are obtained. Thus, it is found that the average monthly amounts of Q in the continental part of Antarctica on the high plateau (Vostok station) in conditions of minimal cloudiness and high transparency during the Antarctic summer are maximum and average 1240 MJ/m2. At the same time, at the tip of the Antarctic Peninsula (Bellingshausen station) during the same period, the average monthly amounts of Q due to the almost constantly present cloud cover do not exceed 570 MJ/m2. In the coastal areas at the three remaining stations, the average monthly amounts of total radiation range from 908 MJ/m2 (Progress) to 950 MJ/m2 (Mirny). Estimates of variability characteristics of daily, monthly, and annual sums of total radiation at all the five stations for the entire observation period up to 2019 were also obtained. The absence of statistically significant long-term trends in the annual and monthly sums of total radiation at all the stations under consideration was noted. The results of their analysis indicate that there are no significant changes in the inflow of total solar radiation to the Antarctic surface over more than sixty years of actinometric observations.

METABOLIC STUDIES WITH 131I-LABELED THYROXINE. II.

1963 ◽  
Vol 44 (3) ◽  
pp. 475-480 ◽  
Author(s):  
R. Grinberg
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Optic Nerve ◽  
Pituitary Gland ◽  
Time Interval ◽  
Time Intervals ◽  
Pituitary Glands ◽  
The Central Nervous System ◽  
Tentative Explanation

ABSTRACT Radiologically thyroidectomized female Swiss mice were injected intraperitoneally with 131I-labeled thyroxine (T4*), and were studied at time intervals of 30 minutes and 4, 28, 48 and 72 hours after injection, 10 mice for each time interval. The organs of the central nervous system and the pituitary glands were chromatographed, and likewise serum from the same animal. The chromatographic studies revealed a compound with the same mobility as 131I-labeled triiodothyronine in the organs of the CNS and in the pituitary gland, but this compound was not present in the serum. In most of the chromatographic studies, the peaks for I, T4 and T3 coincided with those for the standards. In several instances, however, such an exact coincidence was lacking. A tentative explanation for the presence of T3* in the pituitary gland following the injection of T4* is a deiodinating system in the pituitary gland or else the capacity of the pituitary gland to concentrate T3* formed in other organs. The presence of T3* is apparently a characteristic of most of the CNS (brain, midbrain, medulla and spinal cord); but in the case of the optic nerve, the compound is not present under the conditions of this study.

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