• 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.

• 전기학회논문지
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• 제64권4호
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• pp.505-514
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• 2015

This paper proposes a probabilistic generation assessment model of renewable energy generators(REGs) considering uncertainty of resources, mainly focused on Wind Turbine Generator(WTG) and Solar Cell Generator(SCG) which are dispersed widely in South Korea The proposed numerical analysis method assesses the one day-ahead generation by combining equivalent generation characteristics function and probabilistic distribution function of wind speed(WS) and solar radiation(SR) resources. The equivalent generation functions(EGFs) of the wind and solar farms are established by grouping a lot of the farms appropriately centered on Weather Measurement Station(WMS). First, the EGFs are assessed by using regression analysis method based on typical least square method from the recorded actual generation data and historical resources(WS and SR). Second, the generation of the REGs is assessed by adding the one day-ahead resources forecast, announced by WMS, to the EGFs which are formulated as third order degree polynomials using the regression analysis. Third, a Renewable Energy Generation Assessment System(REGAS) including D/B of recorded actual generation data and historical resources is developed using the model and algorithm predicting one day-ahead power output of renewable energy generators.

• 한국태양에너지학회 논문집
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• 제37권1호
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• pp.39-45
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• 2017

This paper presents the effect of solar collectors on the performance of solar tracking daylighting systems. A series of measurements were made for two different types of solar collectors mounted on double axis solar trackers: Parabolic dish concentrator and Fresnel Lens. Indoor light levels were measured at different locations of an office space (longitude: 126.33 E, latitude 33.45 N) as photo sensors were placed on a task plane 80 cm above the floor. To accurately monitor the applicability of the systems, measurements were performed under clear and overcast sky conditions with the roll-screen (on the south window) in the down position. Comparing the illuminance data, the system with Fresnel lens outperformed that of parabolic dish concentrator. On clear days, the former delivered the light levels of 400~600 lux on the task plane whereas the latter recorded 100~200 lux. Depending on the amount of cloud cover, on overcast days, illuminance readings fluctuated to some extent.

• 융합보안논문지
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• 제22권2호
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• pp.99-104
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• 2022

본 연구는 기후변화에 따른 전남 영암지역의 기상변화와 태양광 에너지 생산량의 빅데이터 분석을 통해 상관관계를 도출하여 태양광 에너지 생산 예측 모델을 제시하였다. 사용된 데이터는 공공데이터에서 제공하는 2016년 1월부터 2019년 12월까지의 영암지역의 날씨와 태양에너지 생산량 데이터를 사용하였다. 머신러닝 기법을 활용하여 기상변화와 태양광 에너지 생산량의 회귀분석을 통하여 지역의 날씨와 태양광 에너지 생산량과의 상관 관계식을 도출 하였다. 도출된 예측식을 적용하여 지역의 태양에너지 생산을 계산하였으며, 이를 생산지수로 표현하여 3단계로 구분하였다. 이 같이 구분된 3단계의 생산지수를 통해 향후 기후변화에 따른 태양에너지 생산량을 예측하고, 농업 활동에 있어 중요한 바로미터로 활용될 것이라 판단된다.

• 조명전기설비학회논문지
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• 제23권10호
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• pp.36-44
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• 2009

본 논문에서는 PSA(position solar algorithm)을 이용하여 태양광 추적시스템의 발전 효율을 분석하였다. 태양의 위치 추적시스템은 자연환경 조건에 무관한 태양광 발전시스템에 매우 효과적으로 필요하다. 프로그램 방식의 태양광 추적시스템은 구름이나 대기 조건에 의해 일사량이 급하게 변할 경우에도 오동작 없이 정확하게 태양을 추적을 할 수 있다. 따라서, 본 논문에서는 더욱 정확하게 태양의 위치를 추적하기 위한 PSA 알고리즘을 제시하고, 제시한 알고리즘을 이용하여 태양광 발전시스템의 효율을 분석한다. 또한 적용된 알고리즘에 의해 제어된 고도각 및 방위각을 한국 천문연구원에서 제공된 데이터와 비교한다. 본 논문에서는 고도각 및 방위각 제어의 오차와 적용된 알고리즘의 발전효율을 분석하고 결과를 통하여 적용된 알고리즘의 타당성을 입증한다.

• 한국유기농업학회지
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• 제22권4호
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• pp.593-610
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• 2014

The whole world concentrates on the reduction of greenhouse gas to effectively cope with policy toward global climate change. To effectively react to climate change, even the agricultural sector requires construction of new farming systems that utilizes new and renewable energy because of rising oil prices and regulations for greenhouse gas emissions. For this reason, we need to fuse the new and renewable energy with the horticulture sector of which the light and heat energy cost accounts for great part, moreover, efforts and researches should me done which can increase income of farmers through reducing carbon dioxide and energy cost in agricultural production expenses. Therefore, this study analyzes economic feasibility and applicability of fusing geothermal heat pump and solar power facilities with high-tech glass greenhouse. As a result, it is concluded that there surely are an applicability and economic feasibility if we apply new development system that can be an alternative for problems of securing premises of existing geothermal heat pump and the RPS system as a power generation company in case of solar power. Therefore, using this analysis data, if new empirical studies fusing and implementing agriculture sector with new and renewable energy fields proliferate and be applied to actual rural and agricultural field, it will increase actual income and will become a new advanced agricultural system that effectively deals with world-wide environmental problems.

• 설비공학논문집
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• 제3권4호
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• pp.263-275
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• 1991

Studies on the annual performance of three different type of solar-absorption heat pump system (parallel type, series type, and generator type) are carried out by using the computer simulation. These include the calculation of solar energy from the solar collector, and the revision of computer package, developed by Oak Ridge National Laboratory, to predict the annual performance. Finally using weather data and load conditions, the annual performance are obtained. Results show that the annual operating costs of three solar-absorption heat pump systems are almost same values and 44% lower than that of the pure absorption heat pump system. The total annual input energys of solar-absorption heat pump systems are also about 44% lower than that of the pure absorption heat pump. The nominal size of the solar-absorption heat pump systems can be reduced to a value of 55% that of the pure absorption heat pump that would normally be specified under identical conditions.

• 한국태양에너지학회 논문집
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• 제28권1호
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• pp.51-56
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• 2008

Since the direct normal insolation is a main factor for designing any solar thermal power system, it is necessary to evaluate its characteristics all over the country. We have begun collecting direct normal insolation data since December 1992 at 16 different locations and considerable effort has been made for constructing a standard value from measured data at each station. KIER(Korea Institute of Energy Research)'s new data will be extensively used by solar thermal concentrating system users or designers as well as by research institutes. From the results, we can conclude that 1) Yearly mean $2.67\;kWh/m^2/day$ of the direct normal insolation was evaluated for all days all over the 16 areas in Korea. 2) All day's direct normal insolation of spring and summer were $2.91\;kWh/m^2/day$ and $2.23\;kWHm^2/day$, and for fall and winter their values were $2.78\;kWh/m^2/day$ and $2.77\;kWh/m^2/day$ respectively. So, spring, fall and winter were higher, and summer was lower than the yearly mean value.

• 한국태양에너지학회 논문집
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• 제30권6호
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• pp.118-124
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• 2010

In order to develop commercial model of 10kW dish-Stirling solar thermal power system, modification for the exiting facility was taken for a year as a Leading Project in KIER. During the project, solar tracking system, control and monitoring system and high durability reflector were developed and long term operation were performed. The solar tracking system was tested for four months to investigate the degree of precision and adapted to the control system for an actual operation from October in 2009. The sun tracking accuracy of ${\pm}4$ mrad using modified control system was obtained and the system operated successfully during the experimental period. The monitoring system displays engine pressure, electric generation amounts, generator RPM, receiver temperatures, and etc. from Stirling engine and weather data of Direct Normal Irradiation, Horizontal Global Insolation, wind speed & direction, and atmosphere temperature from weather station. According to the operating results in a clear sky day, electric power of 6,890 W was generated at the DNI value of 850 W/$m^2$ and the averaged solar-to-electricity efficiency during a whole day reached to 18.99%. From the overall operating results, linear power generation trend could be observed with increasing DNI value. The solar-to-electricity efficiency achieved to 19% around the DNI value of 700 W/$m^2$ and increased to 20% when the DNI value goes up to 900 W/$m^2$.

• 조명전기설비학회논문지
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• 제24권4호
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• pp.129-139
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• 2010

본 논문은 대형 병원 건물에 신재생에너지 및 열병합시스템을 설치하였을 경우 에너지 성능해석 및 경제성평가를 도출한 것이다. 태양광, 태양열, 지열, 마이크로터빈 및 마이크로터빈과 지열을 복합한 하이브리드 에너지시스템에 대하여 각각 분석하였다. 분석결과 지열 및 마이크로터빈 시스템이 비교적 양호한 결과를 얻었으며 특히 하이브리드시스템으로 운전하는 경우 병동부의 냉난방공급이 가능하고 경제성평가에서도 매우 좋은 결과를 나타냈다. 이는 빌딩 스마트 그리드시스템의 에너지해석 및 경제성평가 방법을 통한 시스템 구축에 필수적인 자료 활용할 수 있다.