• 태양에너지
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• 제20권1호
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• pp.45-54
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• 2000

본 논문에서는 건물 및 에너지 시스템 시뮬레이션에 적용되는 시간별 기상자료의 핵심항목인 일사량 관련자료의 신뢰성 검증을 위해, 서울지역 성분별 일사량의 장기간 측정치를 이용해 다양한 일사량 직산분리 모델의 정밀성 오차분석을 수행하였다. 1991년$\sim$1998사이 법선면직달일사량 및 수평면전일사량 시간별 측정치중 총 12,710시간의 유효데이타가 분석에 활용되었다. 직산분리 예측모델은 국내외에서 일반적으로 활용되고 있는 5개 모델을 분석하였다. 포트란 프로그램을 작성하여 5개 모델의 이론적 일사량 예측치를 계산하고, 6개의 오차 분석 지표를 이용해 측정치와 예측치의 정밀성이 분석되었다. 분석결과 대부분의 직산분리 모델이 실측치보다 작게 예측하고 있으며, CV(RMSE)가 34%$\sim$48%로 비교적 큰 오차폭을 보였다. 전반적으로 태양고도가 낮은 일출 및 일몰 시간대의 오차폭이 크며, 태양고도에 대한 영향이 회귀모델에 반영된 우전천(宇田川)의 직산분리 모델이 5개 모델중 가장 오차가 작은 것으로 평가되었다.

• 한국태양에너지학회 논문집
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• 제39권3호
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• pp.91-102
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• 2019

Decomposition models are essential in TMY development and solar energy system design. Up until recently, only a few decomposition model related researches are implemented in Korea due to lack of measured direct normal solar irradiance. In contrast, numerous researches have been conducted in various countries, and some quasi-universal composition models have been recommended by several papers. In this research, three decomposition models - Watanabe model, Reindl-2 model and Engerer1 model - are selected and their site-fitted coefficients are developed using measured direct normal solar irradiance in Seoul. R-squared, RMSE, MBE of the site-fitted models are compared with the case of original coefficients and then each other. The comparison result shows that the Reindl-2 model with site-fitted coefficients is best suitable for Seoul. Further researches will be conducted to find the best model using more various measured data of Korean cities and site-fitting methods.

• 한국태양에너지학회 논문집
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• 제38권3호
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• pp.1-20
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• 2018

It is a very important and fundamental process to know accurately the intensity of the solar energy coming into the installed module considering the tilted angle. Europe and the US commonly use a program called PVsyst to convert the global horizontal irradiation to global irradiation on tilted plane. There are two types of models that PVsyst uses to convert to irradiation on tilted plane. In this paper, Perez model, which is a decomposition model and Perez model, which is a transposition model used in PVsyst, are applied based on global horizontal irradiation and global irradiation on tilted plane measured in a specific area. The comparison of the decomposition model shows the effect of the transpostion model on global irradiation on tilted plane conversion by comparing the ratio of the horizontal diffuse irradiation amount of the Watanabe model which are highly trusted in Asia and the Perez model. The comparison of transposition model confirm the error between the measured data and the calculated value which is applied Perez model to global horizontal irradiation decomposed by Perez model and Watanabe model. Based on the two comparisons, This paper propose a method to confirm the reliability of transposition model and reduce the error when PVsyst is used in Korea.

• 한국태양에너지학회 논문집
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• 제39권3호
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• pp.81-89
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• 2019

Long-term solar irradiance data are required for reliable performance evaluation and feasibility analysis of solar photovoltaic systems. However, measurement data of the global horizontal irradiance (GHI) are only available for major cities in Korea. Neither the direct normal irradiance (DNI) nor the diffuse horizontal irradiance (DHI) are available, which are also needed to calculate the irradiance on the tilted surface of PV array. It is a simple approach to take advantage of the decomposition model that extracts DNI and DHI from GHI. In this study, we investigate variations of solar PV power estimation due to the choice of decomposition model. The GHI data from Korea Meteorological Administration (KMA) were used and different sets of typical meteorological year (TMY) data using some well-known decomposition models were generated. Then, power outputs with the different TMY data were calculated, and a variation of 3.7% was estimated due to the choice of decomposition model.

• 한국태양에너지학회 논문집
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• 제39권4호
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• pp.55-67
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• 2019

Recently, as the amount of particulate matter blowing from China increases, the domestic air environment is rapidly deteriorating. This pollution of the atmosphere greatly affects the light energy reaching the ground. Particularly, since the light enters the solar cell module in various forms, the amount of input energy of the solar power generation system may be changed depending on the ratio of direct beam irradiation and diffused horizontal irradiation. In this paper, we analyze how the ratio of direct beam component and diffused component on global horizontal irradiation varies with the atmospheric conditions. In addition, the reliability of the regression equation, designed to decompose the global horizontal irradiation into horizontal direct beam irradiation and diffused horizontal irradiation, was verified according to the level of air pollution. So, we derive the most suitable decomposition model for use in domestic climatic conditions in Korea by comparing the ratio of direct and diffuse component on the horizontal which is calculated with Perez model and Watanabe model using the meteorological weather data observed for 14 months. Finally, to reduce the error of the transposition result, we verified the reliability of the decomposition which depends on the atmospheric environment.

• 설비공학논문집
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• 제29권4호
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• pp.159-166
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• 2017

The growing global interest in energy saving is particularly evident in the building sector. The transmitted solar irradiance is an important input in the prediction of the building-energy load, but it is a value that is difficult to measure. In this paper, a calculation method, for which the total horizontal irradiance that can be easily measured is employed, for the measurement of the transmitted solar irradiance through windows is proposed. The method includes a direct and diffuse split model and a variable-transmittance model. The results of the proposed calculation model are compared with the TRNSYS-simulation results at each stage for the purpose of validation. The final results show that the CVRMSE over the year between the proposed model and the reference is less than 30 %, whereby the ASHRAE guideline was achieved.