scholarly journals A Comprehensive Approach for Modelling Horizontal Diffuse Radiation, Direct Normal Irradiance and Total Tilted Solar Radiation Based on Global Radiation under Danish Climate Conditions

Energies ◽  
2018 ◽  
Vol 11 (5) ◽  
pp. 1315 ◽  
Author(s):  
Zhiyong Tian ◽  
Bengt Perers ◽  
Simon Furbo ◽  
Jianhua Fan ◽  
Jie Deng ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Global Radiation ◽  
Diffuse Radiation ◽  
Comprehensive Approach ◽  
Climate Conditions ◽  
Direct Normal Irradiance

Improved Accuracy Models For Hourly Diffuse Solar Radiation

2005 ◽  
Vol 128 (1) ◽  
pp. 104-117 ◽  
Author(s):  
T. Muneer ◽  
S. Munawwar
Keyword(s):  
Solar Radiation ◽  
Regression Models ◽  
Global Radiation ◽  
Diffuse Radiation ◽  
Evaluation Procedure ◽  
Accuracy Score ◽  
Error Statistics ◽  
Diffuse Solar Radiation ◽  
Energy Applications ◽  
Extensive Evaluation

Solar energy applications require readily available, site-oriented, and long-term solar data. However, the frequent unavailability of diffuse irradiation, in contrast to its need, has led to the evolution of various regression models to predict it from the more commonly available data. Estimating the diffuse component from global radiation is one such technique. The present work focuses on improvement in the accuracy of the models for predicting horizontal diffuse irradiation using hourly solar radiation database from nine sites across the globe. The influence of sunshine fraction, cloud cover, and air mass on estimation of diffuse radiation is investigated. Inclusion of these along with hourly clearness index, leads to the development of a series of models for each site. Estimated values of hourly diffuse radiation are compared with measured values in terms of error statistics and indicators like, R2, mean bias deviation, root mean square deviation, skewness, and kurtosis. A new method called “the accuracy score system” is devised to assess the effect on accuracy with subsequent addition of each parameter and increase in complexity of equation. After an extensive evaluation procedure, extricate but adequate models are recommended as optimum for each of the nine sites. These models were found to be site dependent but the model types were fairly consistent for neighboring stations or locations with similar climates. Also, this study reveals a significant improvement from the conventional k-kt regression models to the presently proposed models.

scholarly journals Simulation and design of collector array units within large systems

2019 ◽  
Author(s):  
Jianhua Fan ◽  
Zhiyong Tian ◽  
Simon Furbo ◽  
Weiqiang Kong ◽  
Daniel Tschopp
Keyword(s):  
Solar Radiation ◽  
Thermal Performance ◽  
Global Radiation ◽  
Diffuse Radiation ◽  
Solar Heating ◽  
Heating Systems ◽  
Global Irradiance ◽  
Radiation Data ◽  
Large Systems ◽  
Beam Component

Solar radiation data is necessary for the design of solar heating systems and used to estimate the thermal performance of solar heating plants. Compared to global irradiance, the direct beam component shows much more variability in space and time. The global radiation split into beam and diffuse radiation on collector plane is important for the evaluation of the performance of different collector types and collector field designs.

scholarly journals Direct effect of aerosols on solar radiation and gross primary production in boreal and hemiboreal forests

2018 ◽  
Vol 18 (24) ◽  
pp. 17863-17881 ◽  
Author(s):  
Ekaterina Ezhova ◽  
Ilona Ylivinkka ◽  
Joel Kuusk ◽  
Kaupo Komsaare ◽  
Marko Vana ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Primary Production ◽  
Direct Effect ◽  
Gross Primary Production ◽  
Global Radiation ◽  
Diffuse Radiation ◽  
Light Use Efficiency ◽  
Diffuse Fraction ◽  
Aerosol Loading ◽  
Use Efficiency

Abstract. The effect of aerosol loading on solar radiation and the subsequent effect on photosynthesis is a relevant question for estimating climate feedback mechanisms. This effect is quantified in the present study using ground-based measurements from five remote sites in boreal and hemiboreal (coniferous and mixed) forests of Eurasia. The diffuse fraction of global radiation associated with the direct effect of aerosols, i.e. excluding the effect of clouds, increases with an increase in the aerosol loading. The increase in the diffuse fraction of global radiation from approximately 0.11 on days characterized by low aerosol loading to 0.2–0.27 on days with relatively high aerosol loading leads to an increase in gross primary production (GPP) between 6 % and 14 % at all sites. The largest increase in GPP (relative to days with low aerosol loading) is observed for two types of ecosystems: a coniferous forest at high latitudes and a mixed forest at the middle latitudes. For the former ecosystem the change in GPP due to the relatively large increase in the diffuse radiation is compensated for by the moderate increase in the light use efficiency. For the latter ecosystem, the increase in the diffuse radiation is smaller for the same aerosol loading, but the smaller change in GPP due to this relationship between radiation and aerosol loading is compensated for by the higher increase in the light use efficiency. The dependence of GPP on the diffuse fraction of solar radiation has a weakly pronounced maximum related to clouds.

scholarly journals Monthly average daily diffuse solar radiation in Poland within the period 2005–2015

2018 ◽  
Vol 23 ◽  
pp. 00020
Author(s):  
Małgorzata Kleniewska ◽  
Dorota Mitrowska ◽  
Bogdan H. Chojnicki
Keyword(s):  
Solar Radiation ◽  
Linear Relationship ◽  
Global Radiation ◽  
Diffuse Radiation ◽  
Diffuse Fraction ◽  
Diffuse Solar Radiation ◽  
Monthly Average

In this paper an 11-year series of daily values of diffuse solar radiation registered at 8 actinometric stations in Poland was used to describe the characteristics of diffuse radiation and diffuse fraction of global radiation for the area of Poland. Based on the monthly average daily diffuse, global and extraterrestrial solar radiation a linear relationship between these elements was determined. The obtained equation enables the calculation of the monthly average daily diffuse solar radiation for Poland and the application of its values to further climatology studies.

scholarly journals Global radiation, photosynthetically active radiation, and the diffuse component dataset of China, 1981–2010

2018 ◽  
Vol 10 (3) ◽  
pp. 1217-1226 ◽  
Author(s):  
Xiaoli Ren ◽  
Honglin He ◽  
Li Zhang ◽  
Guirui Yu
Keyword(s):  
Solar Radiation ◽  
Photosynthetically Active Radiation ◽  
Global Radiation ◽  
Terrestrial Ecosystem ◽  
Diffuse Radiation ◽  
Research Network ◽  
Diffuse Component ◽  
Ecosystem Productivity ◽  
Ecosystem Models ◽  
Active Radiation

Abstract. Solar radiation, especially photosynthetically active radiation (PAR), is the main energy source of plant photosynthesis, and the diffuse component can enhance canopy light use efficiency, thus increasing ecosystem productivity. In order to predict the terrestrial ecosystem productivity precisely, we not only need global radiation and PAR as driving variables, but also need to treat diffuse radiation and diffuse PAR explicitly in ecosystem models. Therefore, we generated a series of radiation datasets, including global radiation, diffuse radiation, PAR, and diffuse PAR of China from 1981 to 2010, based on the observations of the China Meteorology Administration (CMA) and the Chinese Ecosystem Research Network (CERN). The dataset should be useful for the analysis of the spatiotemporal variations of solar radiation in China and the impact of diffuse radiation on terrestrial ecosystem productivity based on ecosystem models. The dataset is freely available from Zenodo on the following website: https://zenodo.org/record/1198894#.Wx6–C_MwWo (https://doi.org/10.11922/sciencedb.555, Ren et al., 2018).

scholarly journals Global radiation, photosynthetically active radiation, and the diffuse components dataset of China, 1981–2010

2018 ◽  
Author(s):  
Xiaoli Ren ◽  
Honglin He ◽  
Li Zhang ◽  
Guirui Yu
Keyword(s):  
Solar Radiation ◽  
Photosynthetically Active Radiation ◽  
Global Radiation ◽  
Terrestrial Ecosystem ◽  
Diffuse Radiation ◽  
Research Network ◽  
Ecosystem Productivity ◽  
Ecosystem Models ◽  
Active Radiation ◽  
The Impact

Abstract. Solar radiation, especially photosynthetically active radiation (PAR), is the main energy source of plant photosynthesis; and the diffuse component can enhance canopy light use efficiency, thus increasing ecosystem productivity. In order to predict the terrestrial ecosystem productivity precisely, we not only need global radiation and PAR as driving variables, but also need to treat diffuse radiation and diffuse PAR explicitly in ecosystem models. Therefore, we generated a series of radiation datasets, including global radiation, diffuse radiation, PAR, and diffuse PAR of China from 1981 to 2010, based on the observations of China Meteorology Administration (CMA) and Chinese Ecosystem Research Network (CERN). The dataset should be useful for the analysis of the spatio-temporal variations of solar radiation in China and the impact of diffuse radiation on terrestrial ecosystem productivity based on ecosystem models. The dataset is freely available from the Zenodo at the website of https://zenodo.org/record/1198894 (DOI: 10.11922/sciencedb.555).

PROCESSING SUNSHINE DURATION MEASUREMENTS FOR THE ASSESSMENT OF SOLAR RADIATION IN CLIMATIC REGIONS OF THE CENTRAL AFRICAN REPUBLIC

2022 ◽  
pp. 1-27
Author(s):  
Venant Sorel Chara-Dackou ◽  
Donatien Njomo ◽  
Mahamat Hassane Babikir ◽  
mbouombouo ngapouth ibrahim ◽  
Gboulie Pofoura Aicha sidica ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Large Scale ◽  
Central African Republic ◽  
Polynomial Regression ◽  
Least Squares Method ◽  
Sunshine Duration ◽  
Global Radiation ◽  
Diffuse Radiation ◽  
Ordinary Least Squares ◽  
Climatic Regions

Abstract The objectives of this work carried out in the Central African Republic are to propose new correlations between the components of solar radiation and the sunshine duration on a horizontal surface on the ground, and then to make an evaluation of the solar potential in the cities of Bambari, Birao and Bangui. Polynomial regression models were used and their parameters were estimated by the ordinary least squares method. A statistical evaluation allowed us to compare the performance of the models. The best correlations are then used to estimate the global and diffuse radiation. In the city of Birao, the estimated global radiation is around 6 kWh/m2.j and the diffuse radiation around 2 kWh/m2.j ; in Bambari the global radiation is around 5.4 kWh/m2.j and the diffuse around 2.3 kWh/m2.j ; in Bangui the global radiation is around 5 kWh/m2.j and the diffuse radiation around 2.3 kWh/m2.j. The potential solar in all these regions is very favorable for small and large-scale solar photovoltaic applications.

scholarly journals Radiação global e difusa diária na região de transição Cerrado-Amazônia brasileira

2021 ◽  
Vol 43 ◽  
pp. e37
Author(s):  
Tamara Zamadei ◽  
Adilson Pacheco de Souza ◽  
Frederico Terra de Almeida ◽  
João Franscisco Escobedo
Keyword(s):  
Solar Radiation ◽  
Aerosol Particles ◽  
Global Radiation ◽  
Diffuse Radiation ◽  
Correction Factors ◽  
Mato Grosso ◽  
Energy Incident ◽  
Biomass Burning Aerosol ◽  
Atmospheric Transmissivity

This study aimed to analyze the seasonal variations in atmospheric transmissivity and solar radiation (global and diffuse) on the horizontal surface in Sinop, Mato Grosso (MT) (11.865°S, 55.485°W, and altitude of 371 m) from 06/02/2011 to 12/31/2014. The values of diffuse radiation were measured using the Melo-Escobedo-Oliveira (MEO) shadow ring, with application of astronomical, geometric, and anisotropic correction factors. The analysis of atmospheric transmissivity was based on the classification of sky cover as cloudy, partly cloudy, partially clear, or clear. The diffuse radiation showed similar behavior to the radiation at the top of the atmosphere, reaching a maximum between October and April (rainy season), while the global radiation displayed higher levels during the dry season (May to September). The average daily global radiation ranged from 22.75±0.61 MJ m−2 d−1 in August to 16.44±1.45 MJ m−2 d−1 in January. In Sinop, cloudy and partly cloudy skies occurred on 45.6% of days and atmospheric transmissivity of global radiation was greater than 55% on 54.6% of days. The variations in diffuse radiation in the region were influenced by cloudiness and the concentration of biomass burning aerosol particles. The diffuse radiation can represent 8.02%–99.12% of the global radiation and 5.33%–29.01% of solar energy incident at the top of the atmosphere.

scholarly journals Development of New Models for the Estimation of Hourly Components of Solar Radiation: Tests, Comparisons, and Application for the Generation of a Solar Database in Morocco

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Mohammed Benchrifa ◽  
Rachid Tadili ◽  
Ahmed Idrissi ◽  
Hajar Essalhi ◽  
Abdellah Mechaqrane
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Statistical Tests ◽  
Global Radiation ◽  
Diffuse Radiation ◽  
Data Bank ◽  
Energy And Environment ◽  
Solar Systems ◽  
In The Beginning

All studies of solar systems need the hourly values of solar fluxes related to the different components of solar radiation. However, for most sites, measurements are not available. The goal of this paper is to establish an hourly solar radiation data bank for the entirety of Morocco. This data bank will contain the energetic components (global, diffuse, direct, and inclined solar radiation) and the spectral components (ultraviolet I UV , infrared I IR , and photosynthetically active radiation I PAR ). To create this database, in the beginning, we build up models for predicting the various components of the hourly solar radiation, from measurements provided by the different stations owned by the Laboratory of Solar Energy and Environment (LESE). Then, these equations will be verified by using statistical tests. Moreover, we compared our results with those obtained by similar studies. Finally, based on the daily database of global radiation provided by the Laboratory of Solar Energy and Environment, we created an hourly database that unites the various components of solar radiation over 10 years for the entirety of Morocco. Regarding the validity study, the statistical indicators showed that the used models have minimal errors that do not exceed, for the global radiation, -2.93% in Rabat, -3.9% in Tangier,-3.28% in Marrakech, and -0.85% in Fez, and for diffuse radiation, -1.09% in Rabat, -0.68% in Fez,-3.08% in Tangier, and -2.49% in Marrakech. These results show the good quality of the used estimation models. Thus, the data bank that we have realized will fill the gap of the hourly solar data and will meet the needs of engineers, installers of solar systems, and researchers who often need an extensive database.

Spatial and temporal patterns of solar radiation based on topography and air temperature

2002 ◽  
Vol 32 (3) ◽  
pp. 487-497 ◽  
Author(s):  
Sinkyu Kang ◽  
Sungwoo Kim ◽  
Dowon Lee
Keyword(s):  
Solar Radiation ◽  
Spatial Scales ◽  
Global Radiation ◽  
Temporal Patterns ◽  
Diffuse Radiation ◽  
Absolute Error ◽  
Spatial And Temporal Patterns ◽  
Model Calculations ◽  
Eastern Area ◽  
Temperature Regimes

Incident solar radiation is a driving force for many ecological and hydrological processes. For this study, we developed TopoRad, a new radiation model, to describe spatial and temporal patterns of daily radiation based on topography and daily temperature regimes. The model was applied to the Mount Jumbong Forest, located in the mid-eastern area of the Korean peninsula; and the model calculations were evaluated by varying the spatial scales of the digital elevation models (DEMs). In the TopoRad, a clearness index was used to calculate global radiation on a horizontal surface and to partition direct and diffuse radiation. Topographic corrections were separately calculated for each direct and diffuse radiation, using daily topographic modifiers calculated from a DEM. TopoRad predicted daily global radiation of five weather stations with a mean absolute error of 3.1 MJ·m–2·day–1 and a mean bias of –0.3 MJ·m–2·day–1. In the spatial application for Mount Jumbong Forest, distinctively different patterns between direct and diffuse radiations were found where direct radiation (5.2 MJ·m–2·day–1) had more influence than diffuse radiation (4.6 MJ·m–2·day–1) on annual mean daily radiation. When the scaling effect was inspected across different spatial resolutions, the predicted global radiation was nonlinearly related to spatial resolutions. As the spatial resolution became more coarse, the predicted radiation decreased for south-facing slopes and increased for north-facing slopes, indicating that the predictions from the models cannot be generalized for gradients. TopoRad is better suited to predict daily radiation in rugged landscapes where fine-scale prediction is required.

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