• 한국태양에너지학회 논문집
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• 제32권3호
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• pp.68-76
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• 2012

Since the solar energy resource is the main input for sizing any solar energy utilization system, it is essential to utilize the solar radiation data as an application and development of solar energy system increase. It will be necessary to understand and evaluate the insolation data. The Korea Institute of Energy Research(KIER) has begun collecting horizontal global insolation data since May, 1982 at 16 different locations in Korea and for the more detailed analysis, images taken by geostationary satellite may be used to estimate solar irradiance fluxes at earth's surface. It is based on the empirical correlation between a satellite derived cloud index and the irradiance at the ground. From the results, the measured data has been collected at 16 different stations and estimated using satellite at 44 different stations over the Korean peninsula from 1982 to 2010. The Result of analysis shows that the annual-average daily global radiation on the horizontal surface is 3.66 $kWh/m^2/day$ and estimated solar radiation fluxes show reliable results for estimating the global radiation with average deviation of -7.2 to +3.7 % from the measured values.

• 응용통계연구
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• 제30권6호
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• pp.1005-1013
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• 2017

본 연구에서는 태양광 발전량 예측에 필요한 일사량을 예측하기 위해 다양한 기상변수를 활용한 다중회귀, ARIMA, ARIMAX 모형을 사용하여 각 모형의 예측 성능을 비교하고자 한다. 예측에 사용된 변수와 시계열 모형에 대해 소개하고, 실제 일사량 예측에 적용하여 일사량을 예측한 결과 운량, 기온, 습도, 대기권 밖 일사량을 활용한 ARIMAX 모형의 성능이 가장 우수하였다.

• 한국농림기상학회지
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• 제11권1호
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• pp.13-18
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• 2009

기상대에서 측정한 '일적산수평면일사량'을 토대로 임의 경사면 상의 '일적산경사면일사량'을 비교적 정확하고 간편하게 알아낼 수 있는 지형보정계수를 고안하였다. 주어진 시간대의 수평면 청천일사량에 대한 경사면 청천일사량의 비율을 '매시일사보정계수'라 정의하고, 청천일사량을 기준으로 수평면의 시간대별 상대 일사강도와 수평면에 대한 경사면의 일사수광비율의 곱으로 표현하였다. 매시일사보정계수를 하루 단위로 적산한 것이 해당 날짜의 지형보정계수이다. 제주도 내 기생화산 '높은오름'의 등고도면 8 방위에서 사면일사수광량을 1년간 관측하는 한편, 이들 지점의 일사량을 지형보정계수에 의해 추정하여 서로 비교하였다. 지형보정계수에 의한 일사추정값의 편차평방근오차는 연평균 $1.61MJ\;m^{-2}$ 이었으나, 4월부터 10월 사이 영농기간에는 절반 이하로 줄어들었다. 경사향에 무관하게 10월에 가장 오차가 작은 반면, 11월에는 경사향에 따른 오차의 변동폭이 가장 컸다. RMSE 값의 연중변동폭은 남향과 북향사면에서 가장 컸고, 남서-남동-북서사면 순으로 줄어들었다. 어떤 경사면이든 365일 동안의 지형보정계수를 한번만 계산해 두면 인근 기상대에서 관측한 임의 날짜의 전천일사량에 이 계수를 적용함으로써 그 날의 적산일사량을 실용적인 오차범위 내에서 추정할 수 있어 복잡지형의 일사수광량 분포를 용이하게 파악할 수 있다.

• 한국태양에너지학회 논문집
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• 제32권3호
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• pp.77-87
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• 2012

Images taken by geostationary satellite may be used to estimate solar irradiance fluxes at earth's surface. It is based on the empirical correlation between a satellite derived cloud index and the irradiance at the ground. For the validation, estimated direct normal Insolation is compared with observed direct normal Insolation at 16 sites over the Korean peninsular from January 1982 to December 2010. Estimated direct normal Insolation shows reliable results with average deviation of -5.4 to +5.9% from the measured values and the yearly averaged direct normal Insolation of Korean peninsula was turned out to be 2.93 $kW/m^2/day$.

• 융복합기술연구소 논문집
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• 제7권2호
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• pp.7-12
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• 2017

At present, the Korea Meteorological Administration (KMA) measures the horizontal solar irradiation and meteorological data with time in 33 areas. Among these measured data, this study analyzed the tendency of applying the new analysis method by using the horizontal solar irradiation and meteorological data with the time which was measured in many regions across the country for thirty years from 1985 to 2014. The method applied to the analysis is to compare the value of the annual total horizontal solar irradiance and meteorological data for one year with the value of those for the previous year of each year, and give +1 when it is higher, and -1 when it is lower. The characteristics and relationships the horizontal solar irradiation and meteorological data in Daegu were evaluated and analyzed. Through the analysis results, the analysis method applied in this study could be well describe the characteristics and relationships of the solar irradiance and meteorological data during some years.

• 한국태양에너지학회 논문집
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• 제32권3호
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• pp.123-128
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• 2012

Computer simulation of buildings and solar energy systems is being used increasingly in energy assessments and design. The purpose of our work is to predict the surface temperature on inclined surfaces based on ISO-TRY typical weather data. To reach this goal, three studies were performed. They consisted of quantifying the accuracy of various well-known three models. The first type of models calculated diffuse horizontal irradiations from global ones and the second type models computed global irradiations on inclined planes from diffuse and global components on a horizontal surface. The third type of model calculated long-wave radiation and surface temperature from ISO-TRY typical weather data. The proposed model can provide an alternative to building designers in estimating the surface temperature and solar irradiation on inclined surfaces where only the typical meteorological data are available.

• 한국태양에너지학회 논문집
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• 제39권3호
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• pp.67-79
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• 2019

The reliable Typical Meteorological Year (TMY) data, sometimes called Test Reference Year (TRY) data, are necessary in the feasibility study of renewable energy installation as well as zero energy building. In Korea, there are available TMY data; TMY from Korea Institute of Energy Research (KIER), TRY from the Korean Solar Energy Society (KSES) and TRY from Passive House Institute Korea (PHIKO). This study aims at examining their characteristics by using Principle Component Analysis (PCA) at six ground observing stations. First step is to investigate the annual averages of meteorological elements from TMY data and their standard deviations. Then, PCA is done to find which principle components are derived from different TMY data. Temperature and solar irradiance are determined as the main principle component of TMY data produced by KIER and KSES at all stations whereas TRY data from PHIKO does not show similar result from those by KIER and KSES.

• Journal of Astronomy and Space Sciences
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• 제25권4호
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• pp.395-404
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• 2008

태양활동프록시(proxies)와 지구연평균 기온아노말리 시계열을 이용하여 기후변화에서 태양활동신호를 찾아보았다. 이를 위해 Lomb & Scargle의 피어리드그램(Periodgram)을 이용하여 태양활동프록시와 기온아노말리 시계열을 주기분석하였다. 또한 EMD(Empirical Mode Decomposition)과 MODWR MRA(Maxial Overlap Discrete Wavelet Transform Multi Resolution Analysis)를 적용하여 두 시계열을 성분분해하고 이들 중 비슷한 주기의 특성을 보이는 성분을 비교하였다. 태양활동프록시는 짧의 주기의 파워가 긴 주기의 파워에 비해서 큰 반면 기온아노말리는 긴 주기에서 더 큰 파워를 보였다 EMD에 의한 성분분해 결과는 약40년보다 긴 주기성을 갖는 성분을 분해해 낼 수 없었지만 잔차 성분은 비교할 수 있었다. MRA에 의한 성분분해를 통해 지구연평균 기온아노말리 시계열에서 태양활동의 변화에 의한 신호를 찾아내었다. 1960년부터 2007년까지 기온상승에 대한 태양의 기여도는 39%로 계산되었다. 기후민감성은 출력신호의 진폭에만 관계하여 기후시스템이 간단한 2계미분방정식으로 근사될 수 있는 가능성에 대해 토의하였다.

• Journal of Astronomy and Space Sciences
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• 제30권2호
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• pp.101-106
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• 2013

The length of solar cycle 23 has been prolonged up to about 13 years. Many studies have speculated that the solar cycle 23/24 minimum will indicate the onset of a grand minimum of solar activity, such as the Maunder Minimum. We check the trends of solar (sunspot number, solar magnetic fields, total solar irradiance, solar radio flux, and frequency of solar X-ray flare), interplanetary (interplanetary magnetic field, solar wind and galactic cosmic ray intensity), and geomagnetic (Ap index) parameters (SIG parameters) during solar cycles 21-24. Most SIG parameters during the period of the solar cycle 23/24 minimum have remarkably low values. Since the 1970s, the space environment has been monitored by ground observatories and satellites. Such prevalently low values of SIG parameters have never been seen. We suggest that these unprecedented conditions of SIG parameters originate from the weakened solar magnetic fields. Meanwhile, the deep 23/24 solar cycle minimum might be the portent of a grand minimum in which the global mean temperature of the lower atmosphere is as low as in the period of Dalton or Maunder minimum.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2001년도 추계학술대회 논문집
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• pp.335-335
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• 2001

Direct-normal, total horizontal and diffuse horizontal irradiance data obtained from a multi-filter rotating shadowband radiometer over seven different wavelength bands (416nm, 151nm, 616nm, 675nm, 870nm and 940nm and the entire spectrum) has been analyzed at Kwangju, South Korea from June 1998 December 2000. The maximum hourly global radiation flux ranged from 0.44 MJ/$m^2$ to 2.68 MJ/$m^2$ at around 11:00-12:00 Hr local time while the maximum hourly diffuse radiation flux ranged from about 0.96 MJ/$m^2$ to 1.37 MJ/$m^2$. The maximum hourly direct irradiance ranged from 1.42 MJ/$m^2$ to 2.92 MJ/$m^2$ from June1998-2000. During the period under consideration, the average monthly global radiation recorded were 13.09 MJ/$m^2$/day, 10.58MJ/$m^2$/day and 9.78MJ/$m^2$/day for years 1998, 1999 and 2000 respectively, while the diffuse irradiance were 6.54 MJ/$m^2$/day, 5.33 MJ/$m^2$/day and 5.14 MJ/$m^2$/day for f998, 1999 and 2000 respectively. The direct irradiance values at the site were 11.63 MJ/$m^2$/day, 8.24MJ/$m^2$/day and 7.75 MJ/$m^2$/day for 1998, f999 and 2000 respectively. It was observed that each of the years has its own unique meteorological parameters that affect the quality and quantity of radiation received for each month. The annual average daily fractions of the diffuse to the global radiation (KD) were 0.51, 0.61 and 0.59 for years 1998, 1999 and 2000 respectively. Analysis indicated that the average daily KD ranged from 0.13 to a maximum value of 0.99 in May for irradiance measured at the broadband channel while the maximum and minimum KD value of 0.91 and 0.23 was recorded at wavelength band 870nm and 940nm in January and September respectively. The lowest average daily clearness index (Kt) value recorded was 0.03 in May (Spring) and the annual average daily clearness indexes are 0.45, 0.34 and 0.35 for years 1998, f999 and 2000 respectively. The frequency of clear days annually at Kwangju is 67.95%, 29.57% and 40.72% for years 1998, 1999 and 2000 respectively.