• 대기
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• 제29권5호
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• pp.537-550
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• 2019

To analyze the observation environment of solar radiation stations operated by the Korea Meteorological Administration (KMA), we analyzed the skyline, Sky View Factor (SVF), and solar radiation due to the surrounding topography and artificial structures using a Digital Elevation Model (DEM), 3D camera, and solar radiation model. Solar energy shielding of 25 km around the station was analyzed using 10 m resolution DEM data and the skyline elevation and SVF were analyzed by the surrounding environment using the image captured by the 3D camera. The solar radiation model was used to assess the contribution of the environment to solar radiation. Because the skyline elevation retrieved from the DEM is different from the actual environment, it is compared with the results obtained from the 3D camera. From the skyline and SVF calculations, it was observed that some stations were shielded by the surrounding environment at sunrise and sunset. The topographic effect of 3D camera is therefore more than 20 times higher than that of DEM throughout the year for monthly accumulated solar radiation. Due to relatively low solar radiation in winter, the solar radiation shielding is large in winter. Also, for the annual accumulated solar radiation, the difference of the global solar radiation calculated using the 3D camera was 176.70 MJ (solar radiation with 7 days; suppose daily accumulated solar radiation 26 MJ) on an average and a maximum of 439.90 MJ (solar radiation with 17.5 days).

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.200.1-200.1
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• 2010

Solar energy is one of the most promising energy resources in the future. For the application and dissemination of solar energy technologies in various fields, reliable data sets of solar irradiation are needed for engineers, researchers, businessmen, and policy makers. Global horizontal solar radiation is needed for the use of flat plate collector, solar domestic hot water system, photovoltaic devices and passive systems like green house. In many countries, solar radiation data accumulated for more then 40 or 50 years and typical weather data are published with average of more then 30 years. In Korea, those global total radiations are measured for about 30 years. With the connections of computer network, measured data could be transmitted to the central control system at key station through Ethernet lines. The data acquisition systems are connected to be automatically controlled by the monitoring network. Global horizontal solar radiation data 16 locations were measured and averaged from 1982 to 2008.

• 생물환경조절학회지
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• 제17권3호
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• pp.215-220
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• 2008

본 시험은 펄라이트 배지에서 적산일사량에 따른 급액이 장미 'Cardinal'의 생육에 미치는 영향을 고찰하기 위하여 수행하였다. 배지내의 pH는 6.0에서 6.1사이로 안정적이었고 EC는 급액보다는 배액에서 높게 나타났는데 후기로 갈수록 높아지는 경향이었다. 무기 성분은 비순환식 C. Sonneveld처방 기준으로 보면 인산과 칼리, 마그네슘이 집적됨을 알 수 있었는데, 특히 칼리와 마그네슘은 각각 기준량 195ppm, 18보다 집적됨을 알 수 있었다. 배지의 배액율은 전체적으로는 일사량이 많으면 높아지는 경향이었다. 장미 수액은 오전 9시 경부터 12시까지 흐름이 있었는데, 10시 30분에서 11시 사이에 $273g{\cdot}hr^{-1}$이었는데 일사량에 비례하여 수액흐름이 증가하지는 않았다. 양액소모량은 $250W{\cdot}hr^{-1}$에서는 50m1구에서 212.8ml로 많았는데 수량도 154.6본/10a로 많아 양액소모량이 수량에 영향을 미치는 것을 알 수 있었다. 펄라이트 배지에서 양액공급량은 11월부터 3월에 $200W{\cdot}hr^{-1}$에서 50ml를 1일 $6\sim10$회 급액하고 일사량이 많을 때는 $250W{\cdot}hr^{-1}$에서 30ml를 1일 $22\sim30$회 급액하는 것이 좋을 것으로 생각된다.

• 대기
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• 제29권1호
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• pp.61-74
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• 2019

To investigate the observational environment, sky line and skyview factor (SVF) are calculated using a digital elevation model (DEM; 10 m spatial resolution) and 3 dimensional (3D) sky image at radiation site, Gangneung-Wonju National University (GWNU). Solar radiation is calculated using GWNU solar radiation model with and without the sky line and the SVF retrieved from the 3D sky image and DEM. When compared with the maximum sky line elevation from Skyview, the result from 3D camera is higher by $3^{\circ}$ and that from DEM is lower by $7^{\circ}$. The SVF calculated from 3D camera, DEM and Skyview is 0.991, 0.998, and 0.993, respectively. When the solar path is analyzed using astronomical solar map with time, the sky line by 3D camera shield the direct solar radiation up to $14^{\circ}$ with solar altitude at winter solstice. The solar radiation is calculated with minutely, and monthly and annual accumulated using the GWNU model. During the summer and winter solstice, the GWNU radiation site is shielded from direct solar radiation by the west mountain 40 and 60 minutes before sunset, respectively. The monthly difference between plane and real surface is up to $29.18M\;m^{-2}$ with 3D camera in November, while that with DEM is $4.87M\;m^{-2}$ in January. The difference in the annual accumulated solar radiation is $208.50M\;m^{-2}$ (2.65%) and $47.96M\;m^{-2}$ (0.63%) with direct solar radiation and $30.93M\;m^{-2}$ (0.58%) and $3.84M\;m^{-2}$ (0.07%) with global solar radiation, respectively.

• 한국태양에너지학회 논문집
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• 제32권2호
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• pp.64-73
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• 2012

The angle of solar panels is calculated using solar radiation model for the efficient solar power generation. In ideal state, the time of maximum solar radiation is represented from 12:08 to 12:40 during a year at Gangneung and it save rage time is12:23. The maximum solar radiation is 1012$W/m^2$ and 708$W/m^2$ inc lear sky and cloudy sky, respectively. Solar radiation is more sensitive to North-South (N-S) slope angle than East-West (E-W) azimuth angle. Daily solar radiation on optimum angle of solar panel is higher than that on horizontal surface except for 90 days during summer. In order to apply to the real atmosphere, the TMY (typical meteorological Year) data which obtained from the 22 solar sites operated by KMA(Korea Meteorological Administration) during 11 years(2000 to 2010) is used as the input data of solar radiation model. The distribution of calculated solar radiation is similar to the observation, except in Andong, where it is overestimated, and in Mokpo and Heuksando, where it is underestimated. Statistical analysis is performed on calculated and observed monthly solar radiation on horizontal surface, and the calculation is overestimated from the observation. Correlationis 0.95 and RMSE (Root Mean Square Error) is10.81 MJ. The result shows that optimum N-S slope angles of solar panel are about $2^{\circ}$ lower than station latitude, but E-W slope angles are lower than ${\pm}1^{\circ}$. There are three types of solar panels: horizontal, fixed with optimum slope angle, and panels with tracker system. The energy efficiencies are on average 20% higher on fixed solar panel and 60% higher on tracker solar panel than compared to the horizontal solar panel, respectively.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.342-347
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• 2011

Solar energy is attenuated by absorbing gases (ozone, aerosol, water vapour and mixed gas) and cloud in the atmosphere. And these are measured with solar instruments (pyranometer, phyheliometer). However, solar energy is insufficient to represent detailed energy distribution, because the distributions of instruments are limited on spatial. If input data of solar radiation model is accurate, the solar energy reaches at the surface can be calculated accurately. Recently a variety of satellite measurements are available to TERA/AQUA (MODIS), AURA (OMI) and geostationary satellites (GMS-5, GOES-9, MTSAT-1R, MTSAT-2 and COMS). Input data of solar radiation model can be used aerosols and surface albedo of MODIS, total ozone amount of OMI and cloud fraction of meteorological geostationary satellite. The solar energy reaches to the surface is calculated hourly by solar radiation model and those are accumulated monthly and annual. And these results are verified the spatial distribution and validated with ground observations.

• Current Optics and Photonics
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• 제1권4호
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• pp.263-270
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• 2017

Solar radiation data measured by pyranometers is of fundamental use in various fields. In the field of atmospheric optics, the measurement of solar energy must be precise, and the equipment needs to be maintained frequently. However, there seem to be many errors with the existing type of pyranometer, which is an element of the solar-energy observation apparatus. In particular, the error caused by the thermal dome effect occurs because of the thermal offset generated from a temperature difference between outer dome and inner casing. To resolve the thermal dome effect, intensive observation was conducted using the method and instrument designed by Ji and Tsay. The characteristics of the observed global solar radiation were analyzed by classifying the observation period into clear, cloudy, and rainy cases. For the clear-weather case, the temperature difference between the pyranometer's case and dome was highest, and the thermal dome effect was $0.88MJ\;m^{-2}\;day^{-1}$. Meanwhile, the thermal dome effect in the cloudy case was $0.69MJ\;m^{-2}\;day^{-1}$, because the reduced global solar radiation thus reduced the temperature difference between case and dome. In addition, the rainy case had the smallest temperature difference of $0.21MJ\;m^{-2}\;day^{-1}$. The quantification of this thermal dome effect with respect to the daily accumulated global solar radiation gives calculated errors in the cloudy, rainy, and clear cases of 6.53%, 6.38%, and 5.41% respectively.

• 한국작물학회지
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• 제35권2호
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• pp.151-155
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• 1990

콩군락에 흡수된 단파폭사와 건물생산과의 관계를 단경밀식적응품종인 팔달콩을 공시하여 조사한 결과를 요약하면 다음과 같다. 1. 단파폭사의 군락에서의 감쇄계수는 0.53, 총투과된 양은 입사된 단파폭사량의 31.9%이었다. 2. 생육시기별 지하부 건물중과 그 기간에 군락이 흡수한 단파폭사의 적산치는 등숙기인 출현후 88일항까지는 직선적 비례관계가 성립하였고, 건물로의 변환효율인 비례계수는 1.45gMJ$^{-1}$이었다. 3. 생육기간의 전체반사율은 24.7%이었으며 엽면적지수(LAI) 2.5 이상에서는 입사량에서 투과량을 뺀값과 반사폭사량간의 상관도가 높았다.

• 생물환경조절학회지
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• 제31권4호
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• pp.432-437
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• 2022

본 연구에서는 '설향' 딸기를 두 작기(2020-2021년, 2021-2022년)에 걸쳐 재배하면서 외부 광환경과 생육도일온도가 작물 생산량에 미치는 영향을 분석하였다. 2년 동안 온실 내 환경 관리, 양액 관리 등은 동일하게 하였다. 재배기간 중 주간의 온실 온습도는 두 작기에서 유사하게 관리되었고, 야간의 온습도는 통계적으로 차이가 있었으나 작물 생육 범위를 벗어나지 않았다. 일사량은 9월과 10월에 첫번째 작기의 일평균 일사량이 많아 누적일사량도 많았으며, 11월부터는 2월까지는 두 번째 작기의 일사량, 3월에는 다시 첫번째 작기의 일사량이 많은 것으로 나타나 1월부터의 누적일사량은 두 번째 작기에서 많은 것으로 나타났다. 딸기의 최적 일장 조건인 8시간 이상의 일장이 나타난 일은 두 작기 간 큰 차이가 없었고, 변화 양상은 누적일사량의 변화와 유사하게 나타났다. 누적일사량과 생육도일온도는 상관관계가 커 생육도일온도가 딸기의 생산량과 당도에 미치는 영향을 조사해 본 결과의 초기의 누적일사량과 생육도일온도가 적었던 두 번째 작기에서 초기 수확량은 적었으나 누적일사량 및 생육도일온도가 증가함에 따라 후기에 수확량이 첫번째 작기보다 많았으며 잠재적 최대 생산량도 큰 것으로 나타났다. 당도는 생육도일온도가 증가함에 따라 감소하였으며, 이는 촉성딸기의 특성으로 판단된다. 추후 연구를 통해 단순 수확량뿐만 아니라 작물 생육, 꽃눈분화 및 출뢰시기를 조사, 분석하여 생육도일온도가 작물 생육에 미치는 영향을 다각도로 분석하는 연구도 필요하다고 판단된다.

• 신재생에너지
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• 제8권2호
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• pp.14-23
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• 2012

The TMY (Typical Meteorological Year) for the solar energy study is generated using observation data with 22 solar sites from KMA (Korea Meteorological Administration) during 11 years (2000-2010). The meteorological data for calculation the TMY are used solar radiation, temperature, dew point temperature, wind speed and humidity data. And the TMY is calculated to apply the FS (Finkelstein and Schafer) statistics and RMSE (Root Mean Squared Error) methods. FS statistics performed with each point and each variable and then selected top five candidate TMM months with statistical analysis and normalization. Finally TMY is generated to select the highest TMM score with evaluation the average errors for the 22 whole points. The TMY data is represented average state and long time variations with 22 sites and meteorological data. When TMY validated with the 11-year daily solar radiation data, the correlation coefficient was about 0.40 and the highest value is 0.57 in April and the lowest value is 0.23 in May. Mean monthly solar radiation of TMY is 411.72 MJ which is 4 MJ higher than original data. Average correlation coefficient is 0.71, the lowest correlation is 0.43 in May and the highest correlation is 0.90 in January. Accumulated annual solar radiation by TMY have higher value in south coast and southwestern region and have relatively low in middle regions. And also, differences between TMY and 11-year mean of is distributed lower 100 MJ in Kyeongbuk, higher 200 MJ in Jeju and higher 125 MJ in Jeonbuk and Jeonnam, respectively.