• Solar Energy
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• v.20 no.3
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• pp.21-30
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• 2000

It is necessary to estimate the regression coefficients in order to predict the monthly mean daily global radiation on a horizontal surface. Therefore many different equations have proposed to evaluate them for certain areas. In this work, a new correlation has been made to predict the solar radiation for any area over Korea by estimating the regression coefficients taking into account percentage of possible sunshine, and cloud cover. Particularly, the multiple linear regression model proposed shows reliable results for estimating the global radiation with average deviation of -1 to 3 % from the measured values.

• Solar Energy
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• v.11 no.1
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• pp.3-15
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• 1991

In this study global radiation and global illumination are directly measured and diffuse radiation and diffuse illumination measured utilizing semi-circular shadow ring. By analyzing measured radiation data, clear and overcast sky are classified according to the sky classification method used in Mantes, France. Measured illumination data are analyzed and 1) Clear sky illumination on a horizontal surface as a function of solar altitude. 2) Overcast sky illumination on a horizontal surface as a function of solar altitude, 3) Monthly variation of illumination. 4) Cumulative percentage of illumination, 5) Daylight intensity as a function of hours in a typical day, 6) Average number hours per day of illumination above 10 and 20klx are presented as a climatic data for daylighting design for Seoul, Korea.

• Journal of the Korean Solar Energy Society
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• v.21 no.4
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• pp.73-83
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• 2001

Since the solar radiation is the main input for sizing any solar system, it will be necessary to understand and evaluate the insolation data. The horizontal global insolation data have been measured since May, 1982 and direct normal solar insolation data since December 1990 at 16 different sites all over the country and considerable effort has been made for constructing a standard value from measured data at each station. In the results, the average global total solar radiation of the nation is $3,055kcal/m^2.day(12.79MJ/m^2.day)$ and the average clear day direct normal solar beam radiation was $4,600kcal/m^2.day(19.26MJ/m^2.day)$, which indicates possible solar energy application of medium and high temperature technologies with high concentration.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.12
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• pp.467-476
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• 2016

As the energy saving issues become one of the important global agenda, the building simulation method is generally used to predict the inside energy usage to establish the power-saving strategies. To foretell an accurate energy usage of a building, proper and typical weather data are needed. For this reason, typical weather data are fundamental in building energy simulations and among the meteorological factors, the solar irradiation is the most important element. Therefore, preparing solar irradiation is a basic factor. However, there are few places where the horizontal solar radiation in domestic weather stations can be measured, so the prediction of the solar radiation is needed to arrive at typical weather data. In this paper, four solar radiation prediction models were analyzed in terms of their applicability for domestic weather conditions. A total of 12 regions were analyzed to compare the differences of solar irradiation between measurements and the prediction results. The applicability of the solar irradiation prediction model for a certain region was determined by the comparisons. The results were that the Zhang and Huang model showed the highest accuracy (Rad 0.87~0.80) in most of the analyzed regions. The Kasten model which utilizes a simple regression equation exhibited the second-highest accuracy. The Angstrom-Prescott model is easily used, also by employing a plain regression equation Lastly, the Winslow model which is known for predicting global horizontal solar irradiation at any climate regions uses a daily integration equation and showed a low accuracy regarding the domestic climate conditions in Korea.

• Journal of the Korean Solar Energy Society
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• v.23 no.3
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• pp.23-28
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• 2003

The purpose of this study is to procure basic data to be used for solar power plant and concentrating collector designs. Site elevation is one of the major factors which influences the incoming insolation to the earth surface. Because the nonpermanent gases such as ozone, water vapor are unmixed components of the atmosphere and their concentrations are the function of height, the site elevation effects the relative proportion of the atmospheric constituents. We have measured solar radiation on Jiri Mt. (1,400m) and in Gurye area(115m) at the near same latitude. These values were then compared to obtain their characteristics and to investigate the potential for the solar utilization for both high and low elevated areas. From the experimental results, we concluded that 1) Daily mean horizontal global radiation and normal beam radiation on Mt. Jiri are 9.5%, and 35.3% higher than Gurye area respectively for a clear day. 2) A significant difference in atmospheric clearness index is observed between Mt. Jiri and Gurye areas.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.146-149
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• 2008

Since the atmospheric clearness index is main factor for evaluating global-dimming of atmosphere environment, it is necessary to estimate its characteristics all over the major cities in Korea. We have begun collecting clearness index data since 1982 at 16 different cities and considerable effort has been made for constructing a standard value from measured data at each city. The new clearness data for global-dimming analysis will be extensively used by evaluating atmospheric environment as well as by solar PV application system designer or users. From the results, we can conclude that 1) Yearly mean 61.9 % of the atmospheric clearness index was evaluated for clear day all over 2) A significant difference of atmospheric clearness index is observed between 1982-1989 and1990-1997, 1998-2005 through 16 different cities in Korea.

• Journal of the Korean Solar Energy Society
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• v.27 no.2
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• pp.45-52
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• 2007

Since the atmospheric clearness index is main factor for evaluating global-dimming of atmosphere environment, it is necessary to estimate its characteristics all over the major cities in Korea. We have begun collecting clearness index data since 1982 at 16 different cities and considerable effort has been made for constructing a standard value from measured data at each city. The new clearness data for global-dimming analysis will be extensively used by evaluating atmospheric environment as well as by solar PV application system designer or users. From the results, we can conclude that 1) Yearly mean 61.9% of the atmospheric clearness index was evaluated for clear day all over 2) A significant difference of atmospheric clearness index is observed between 1982-1989 and 1990-1997, 1998-2005 through 16 different cities in Korea.

• New & Renewable Energy
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• v.10 no.2
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• pp.29-39
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• 2014

This study examines the future variability of surface wind speed and solar radiation based on climate change scenario over the Korean Peninsula. Climate change scenarios used in this study are RCP 4.5 and 8.5 with a 12.5 km horizontal resolution. Climate change scenario RCP 4.5 and 8.5 reproduce the general features of wind speed over the Korean Peninsula, such as strong wind speed during spring and winter and weak wind speed during summer. When compared with the values of wind speed and solar radiation of the future, they are expected to decrease current wind and solar resource map. Comparing the resource maps using RCP 4.5 and 8.5 scenarios, wind speed and solar radiation decrease with increasing greenhouse gas concentration. Meteorological resource maps of future wind and solar radiation should be improved with high resolution for the industrial application.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.171-173
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• 2008

The amount of incident solar rays on inclined surfaces with various directions has been widely utilized as important data in installing solar collector, hot water system, and designing solar buildings and house. This is because the performance of the solar energy applied systems is much affected by angle and direction of incident rays. Recognizing those factors mentioned above are of importance, actual experiment has been performed in this research to obtain the angle of inclination with which the maximum incident rays can be absorbed. The results obtained in this research could be used in designing optimal solar thermal systems.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.63-67
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• 2011

KnowledgThe Korea Institute of Energy Research(KIER) has begun collecting horizontal global insolation data since May, 1982 at different locations. Because of a poor reliability of existing data, KIER's new data will be extensively used by the solar system users as well as by research institutes. But the quality of solar insolation data is not always good. This reports on an attempt to identify systematic error in such data using clear-day analysis for data rehabilitation. Clear-day analysis is successful in uncovering solar insolation data of questionable quality. It is not proven that rehabilitation process can improve the quality of data for daily or monthly means, but it is suggested that the method can be used to improve the quality of data for monthly means of several years for use in many applications of solar energy plarming. Earlier studies finding a maximum ETR of about 0.80 are confirmed.