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.

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.

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.

scholarly journals Determining the Number of Solar Modules of a 1kW Solar Energy System in Antalya, Turkey

2018 ◽  
Vol 1 (1) ◽  
pp. 521-525
Author(s):  
Ceyda Aksoy Tırmıkçı ◽  
Cenk Yavuz
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Tilt Angle ◽  
Energy System ◽  
Energy Output ◽  
Total Solar Radiation ◽  
Energy Relation ◽  
Solar Module ◽  
The City ◽  
Daily Total

In this paper the number of solar modules of a 1kW solar energy system was determined by using the total solar radiation and the solar module energy output energy relation. The total solar radiation was correlated with the tilt angle of solar modules. Thus the optimum yearly tilt angle of solar modules was calculated and assumed that solar modules of the system were tilted at this angle. In conclusion the monthly average daily total solar radiation, optimum yearly tilt angle and the number of solar modules of the related system were established for the city.

Empirical evidence for a nonlinear effect of galactic cosmic rays on clouds

2006 ◽  
Vol 462 (2068) ◽  
pp. 1221-1233 ◽  
Author(s):  
R.Giles Harrison ◽  
David B Stephenson
Keyword(s):  
Cosmic Rays ◽  
Solar Radiation ◽  
Cosmic Ray ◽  
Diffuse Radiation ◽  
Galactic Cosmic Rays ◽  
Total Solar Radiation ◽  
Diffuse Fraction ◽  
Diffuse Solar Radiation ◽  
The Uk ◽  
Cosmic Ray Flux

Galactic cosmic ray (GCR) changes have been suggested to affect weather and climate, and new evidence is presented here directly linking GCRs with clouds. Clouds increase the diffuse solar radiation, measured continuously at UK surface meteorological sites since 1947. The ratio of diffuse to total solar radiation—the diffuse fraction (DF)—is used to infer cloud, and is compared with the daily mean neutron count rate measured at Climax, Colorado from 1951–2000, which provides a globally representative indicator of cosmic rays. Across the UK, on days of high cosmic ray flux (above 3600×10 2  neutron counts h −1 , which occur 87% of the time on average) compared with low cosmic ray flux, (i) the chance of an overcast day increases by (19±4) %, and (ii) the diffuse fraction increases by (2±0.3) %. During sudden transient reductions in cosmic rays (e.g. Forbush events), simultaneous decreases occur in the diffuse fraction. The diffuse radiation changes are, therefore, unambiguously due to cosmic rays. Although the statistically significant nonlinear cosmic ray effect is small, it will have a considerably larger aggregate effect on longer timescale (e.g. centennial) climate variations when day-to-day variability averages out.

scholarly journals Modeling of the hourly horizontal solar diffuse radiation in Sanliurfa, Turkey

2020 ◽  
Vol 24 (2 Part A) ◽  
pp. 939-950
Author(s):  
Nesrin Beyazit ◽  
Fatih Unal ◽  
Husamettin Bulut
Keyword(s):  
Solar Radiation ◽  
Tracking System ◽  
Measurement Data ◽  
Diffuse Radiation ◽  
Measuring Instruments ◽  
Estimation Model ◽  
Diffuse Solar Radiation ◽  
Statistical Errors ◽  
Solar Tracking ◽  
Solar Diffuse Radiation

Horizontal diffuse solar radiation has been calculated over various models by using the total radiation data obtained from the horizontal surface due to reasons such as lack of adequate measurements and expensive measuring instruments. In this study, the measurements were calculated using the obtained data between the years 2009 and 2016 from solar radiation measurement system with solar tracking system, which belongs to the Department of Mechanical Engineering, Sanliurfa Harran University, Turkey. Three horizontal solar diffuse radiation models have been proposed by using the relationship between the diffuse radiation ratio and the clarity index obtained by eight years? data. Horizontal solar diffuse radiation values were calculated and compared with the measurement data for Sanliurfa by using 15 models of diffuse radiation given in the literature and the results obtained from the models. The statistical errors of the proposed models and 15 different diffusive radiation models were calculated. As diffuse radiation varies with time, it is determined that modelling of Model 1 and Model 2 obtained from Sanliurfa data gives better results in terms of clarity index constraints. Furthermore, although the desired success cannot be achieved with Model 2 in terms of tstat, it has been determined that the relevant model provides better results than many models when compared to statistical errors. With the improvements to be made on Model 2, a local estimation model is thought to give better results.

Environmental life cycle analysis of a fixed PV energy system and a two-axis sun tracking PV energy system in a low-energy house in Turkey

2019 ◽  
Vol 8 (5) ◽  
pp. 391-399
Author(s):  
Ceyda Aksoy Tırmıkçı ◽  
Cenk Yavuz
Keyword(s):  
Life Cycle ◽  
Solar Radiation ◽  
System Design ◽  
Tracking System ◽  
Energy System ◽  
Energy Output ◽  
Total Solar Radiation ◽  
Content Type ◽  
Pv Modules ◽  
Fixed System

Purpose The purpose of this paper is to propose a fixed PV energy system design and a sun tracking PV energy system design to meet the primitive energy demands of a typical house in Sakarya, Turkey with energy payback times (EPBT) and greenhouse payback times (GPBT) calculations. Design/methodology/approach The designs were developed based on the total solar radiation received on the surface of the PV modules. The EPBT and the GPBT of the designs were investigated by utilizing the current embodied energy data of the literature and annual energy output of the proposed systems. The monthly mean total solar radiation, the yearly total solar radiation and the annual energy output of the systems were calculated according to the results of previous studies of authors on 80-W prototypes of a fixed PV energy system tilted at the yearly optimum tilt angle of Sakarya and a two-axis sun tracking PV energy system. Findings The annual energy outputs of the fixed system and the tracking system were established to be 10.092 and 10.311 MJ, respectively. EPBT of the systems were estimated 15.347 years for the fixed system and 11.932 years for the tracking systems which were less than the lifespan of PV modules. The greenhouse gas emitted to produce and install the systems were estimated to be 6,899.342 kg for the fixed system and 5,040.097 kg for the tracking system. GPBT of the systems were calculated to be 5.203 and 2.658 years, respectively. Originality/value PV energy is clean without greenhouse gas emission during the operation. However, significant emissions occur in the life cycle of PV modules until the installation is completed. Therefore reducing the number of PV modules make great differences in the GPBT of PV energy systems. In this paper, comparisons between the GPBT results of the optimally tilted fixed system and tracking system were performed to discuss the best option by means of environmental concerns.

scholarly journals Solar Irradiation Evaluation through GIS Analysis Based on Grid Resolution and a Mathematical Model: A Case Study in Northeast Mexico

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6427
Author(s):  
Fausto André Valenzuela-Domínguez ◽  
Luis Alfonso Santa Cruz ◽  
Enrique A. Enríquez-Velásquez ◽  
Luis C. Félix-Herrán ◽  
Victor H. Benitez ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Solar Radiation ◽  
Solar Energy ◽  
Ground Surface ◽  
Solar Irradiation ◽  
Easy Access ◽  
Total Solar Radiation ◽  
Gis Analysis ◽  
Key Factor ◽  
Solar Resource

The estimation of the solar resource on certain surfaces of the planet is a key factor in deciding where to establish solar energy collection systems. This research uses a mathematical model based on easy-access geographic and meteorological information to calculate total solar radiation at ground surface. This information is used to create a GIS analysis of the State of Nuevo León in Mexico and identify solar energy opportunities in the territory. The analyzed area was divided into a grid and the coordinates of each corner are used to feed the mathematical model. The obtained results were validated with statistical analyses and satellite-based estimations from the National Aeronautics and Space Administration (NASA). The applied approach and the results may be replicated to estimate solar radiation in other regions of the planet without requiring readings from on-site meteorological stations and therefore reducing the cost of decision-making regarding where to place the solar energy collection equipment.

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