Estimation of global solar radiation under clear sky radiation in Turkey

2000 ◽  
Vol 21 (2) ◽  
pp. 271-287 ◽  
Author(s):  
Inci Turk Toğrul ◽  
Hasan Toğrul ◽  
Duygu Evin
Keyword(s):  
Solar Radiation ◽  
Global Solar Radiation ◽  
Clear Sky

scholarly journals SolarisNet : A deep regression network for solar radiation prediction

MAUSAM ◽  
2021 ◽  
Vol 71 (3) ◽  
pp. 443-450
Author(s):  
DEY SUBHADIP ◽  
PRATIHER SAWON ◽  
MUKHERJEE CHANCHAL KUMAR ◽  
BANERJEE SAON
Keyword(s):  
Solar Radiation ◽  
Global Solar Radiation ◽  
Parametric Models ◽  
High Tech ◽  
Short Term ◽  
Effective Utilization ◽  
Clear Sky ◽  
Past Data ◽  
Weather Stations ◽  
Short Term Forecasting

Effective utilization of photovoltaic (PV) plants requires weather variability robust global solar radiation (GSR) forecasting models. Random weather turbulence phenomena coupled with assumptions of clear sky model as suggested by Hottel pose significant challenges to parametric &non-parametric models in GSR conversion rate estimation. Also, a decent GSR estimate requires costly high-tech radiometer and expert dependent instrument handling and measurements, which are subjective. As such, a computer aided monitoring (CAM) system to evaluate PV plant operation feasibility by employing smart grid past data analytics and deep learning is developed. Our algorithm, SolarisNet is a 6-layer deep neural network trained on data collected at two weather stations located near Kalyani metrological site, West Bengal, India. The daily GSR prediction performance using SolarisNet outperforms the existing state of art and its efficacy in inferring past GSR data insights to comprehend daily and seasonal GSR variability along with its competence for short term forecasting is discussed.

scholarly journals Reconstruction of global solar radiation time series from 1933 to 2013 at the Izaña Atmospheric Observatory

2014 ◽  
Vol 7 (9) ◽  
pp. 3139-3150 ◽  
Author(s):  
R. D. García ◽  
E. Cuevas ◽  
O. E. García ◽  
V. E. Cachorro ◽  
P. Pallé ◽  
...  
Keyword(s):  
Time Series ◽  
Solar Radiation ◽  
North Atlantic ◽  
Sunshine Duration ◽  
Global Solar Radiation ◽  
Global Scale ◽  
High Mountain ◽  
Atlantic Region ◽  
Clear Sky ◽  
Radiation Time

Abstract. This paper presents the reconstruction of the 80-year time series of daily global solar radiation (GSR) at the subtropical high-mountain Izaña Atmospheric Observatory (IZO) located in Tenerife (The Canary Islands, Spain). For this purpose, we combine GSR estimates from sunshine duration (SD) data using the Ångström–Prescott method over the 1933/1991 period, and GSR observations directly performed by pyranometers between 1992 and 2013. Since GSR measurements have been used as a reference, a strict quality control has been applied based on principles of physical limits and comparison with LibRadtran model. By comparing with high quality GSR measurements, the precision and consistency over time of GSR estimations from SD data have been successfully documented. We obtain an overall root mean square error (RMSE) of 9.2% and an agreement between the variances of GSR estimations and GSR measurements within 92%. Nonetheless, this agreement significantly increases when the GSR estimation is done considering different daily fractions of clear sky (FCS). In that case, RMSE is reduced by half, to about 4.5%, when considering percentages of FCS > 40% (~ 90% of days in the testing period). Furthermore, we prove that the GSR estimations can monitor the GSR anomalies in consistency with GSR measurements and, then, can be suitable for reconstructing solar radiation time series. The reconstructed IZO GSR time series between 1933 and 2013 confirms change points and periods of increases/decreases of solar radiation at Earth's surface observed at a global scale, such as the early brightening, dimming and brightening. This fact supports the consistency of the IZO GSR time series presented in this work, which may be a reference for solar radiation studies in the subtropical North Atlantic region.

scholarly journals Re-construction of global solar radiation time series from 1933 to 2013 at the Izaña Atmospheric Observatory

2014 ◽  
Vol 7 (4) ◽  
pp. 4191-4227 ◽  
Author(s):  
R. D. García ◽  
E. Cuevas ◽  
O. E. García ◽  
V. E. Cachorro ◽  
P. Pallé ◽  
...  
Keyword(s):  
Time Series ◽  
Solar Radiation ◽  
North Atlantic ◽  
Sunshine Duration ◽  
Global Solar Radiation ◽  
Global Scale ◽  
High Mountain ◽  
Clear Sky ◽  
Downward Radiation ◽  
Radiation Time

Abstract. This paper presents the re-construction of the 80 year time series of daily global shortwave downward radiation (SDR) at the subtropical high-mountain Izaña Atmospheric Observatory (IZO, Spain). For this purpose, we combine SDR estimates from sunshine duration (SD) data using the Ångström–Prescott method over the 1933/1991 period, and SDR observations directly performed by pyranometers between 1992 and 2013. Since SDR measurements have been used as a reference, a strict quality control has been applied, when it was not possible data have been re-calibrated by using the LibRadtran model. By comparing to high quality SDR measurements, the precision and consistency over time of SDR estimations from SD data have successfully been documented. We obtain a overall root mean square error (RMSE) of 9.2% and an agreement between the variances of SDR estimations and SDR measurements within 92% (correlation coefficient of 0.96). Nonetheless, this agreement significantly increases when the SDR estimation is done considering different daily fractions of clear sky (FCS). In that case, RMSE is reduced by half, up to about 4.5%, when considering percentages of FCS > 40% (90% of days in the testing period). Furthermore, we prove that the SDR estimations can monitor the SDR anomalies in consistency with SDR measurements and, then, can be suitable for re-constructing solar radiation time series. The re-constructed IZO global SDR time series between 1933 and 2013 confirms discontinuities and periods of increases/decreases of solar radiation at Earth's surface observed at a global scale, such as the early brightening, dimming and brightening. This fact supports the consistency of the IZO SDR time series presented in this work, which may be a reference for solar radiation studies in the subtropical North Atlantic region.

A new simple parameterization of daily clear-sky global solar radiation including horizon effects

2007 ◽  
Vol 48 (1) ◽  
pp. 226-233 ◽  
Author(s):  
Gabriel López ◽  
F. Javier Batlles ◽  
Joaquín Tovar-Pescador
Keyword(s):  
Solar Radiation ◽  
Global Solar Radiation ◽  
Clear Sky

scholarly journals Enhancement of UV Radiation by Cloud Effect in NE of Brazil

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Chigueru Tiba ◽  
Sérgio da Silva Leal
Keyword(s):  
Solar Radiation ◽  
Uv Radiation ◽  
Extreme Values ◽  
Biological Effects ◽  
Global Solar Radiation ◽  
Seasonal Effect ◽  
Enhancement Effect ◽  
Monthly Basis ◽  
Uv Index ◽  
Clear Sky

This paper reports a detailed analysis of ground-based measurements of cloud-enhanced global solar and UV radiation in NE Brazil in the city of Recife. It was found that (a) the phenomenon of UV enhancement, above clear sky model, is not uncommon and that it occurs on at least eight months; (b) the cumulative duration can reach 13 minutes; (c) there is a clear seasonal effect, and the probability of occurrence on a monthly basis shows two peaks, one in March and another in October; and (d) the most extreme UV radiation was 70.4 W/m2, approximately 6 W/m2 higher than the clear sky UV radiation. The extreme values should be taken into account in the study of effects related to the UV index and biological effects. Two statistical models also were elaborated, to estimate the UV solar radiation, in which the first is for all sky conditions and the second exclusively for situations where the global solar radiation is equal to or higher than 1367 W/m2, resulting from the enhancement effect caused by a particular configuration of the clouds. The statistical indicatives for both models presented, respectively, MBE% of 3.09 and 0.48% and RMSE% of 15.80 and 3.90%.

scholarly journals Characterising Seasonality of Solar Radiation and Solar Farm Output

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 471 ◽  
Author(s):  
John Boland
Keyword(s):  
Solar Radiation ◽  
Electricity Market ◽  
Global Radiation ◽  
International Energy Agency ◽  
Global Solar Radiation ◽  
Clearness Index ◽  
Short Term ◽  
Energy Agency ◽  
Clear Sky ◽  
Short Term Forecasting

With the recent rapid increase in the use of roof top photovoltaic solar systems worldwide, and also, more recently, the dramatic escalation in building grid connected solar farms, especially in Australia, the need for more accurate methods of very short-term forecasting has become a focus of research. The International Energy Agency Tasks 46 and 16 have brought together groups of experts to further this research. In Australia, the Australian Renewable Energy Agency is funding consortia to improve the five minute forecasting of solar farm output, as this is the time scale of the electricity market. The first step in forecasting of either solar radiation or output from solar farms requires the representation of the inherent seasonality. One can characterise the seasonality in climate variables by using either a multiplicative or additive modelling approach. The multiplicative approach with respect to solar radiation can be done by calculating the clearness index, or alternatively estimating the clear sky index. The clearness index is defined as the division of the global solar radiation by the extraterrestrial radiation, a quantity determined only via astronomical formulae. To form the clear sky index one divides the global radiation by a clear sky model. For additive de-seasoning, one subtracts some form of a mean function from the solar radiation. That function could be simply the long term average at the time steps involved, or more formally the addition of terms involving a basis of the function space. An appropriate way to perform this operation is by using a Fourier series set of basis functions. This article will show that for various reasons the additive approach is superior. Also, the differences between the representation for solar energy versus solar farm output will be demonstrated. Finally, there is a short description of the subsequent steps in short-term forecasting.

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