• New & Renewable Energy
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• v.9 no.2
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• pp.15-22
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• 2013

The solar energy are an infinite source of energy and a clean energy without secondary pollution. The global solar energy reaching the earth's surface can be calculated easily according to the change of latitude, altitude, and sloped surface depending on the amount of the actual state of the atmosphere and clouds. The high-resolution solar-meteorological resource map with 1km resolution was developed in 2011 based on GWNU (Gangneung-Wonju National University) solar radiation model with complex terrain. The very high resolution solar energy map can be calculated and analyzed in Seoul and Eunpyung with topological effect using by 1km solar-meteorological resources map, respectively. Seoul DEM (Digital Elevation Model) have 10m resolution from NGII (National Geographic Information Institute) and Eunpyeong new town DSM (Digital Surface Model) have 1m spatial resolution from lidar observations. The solar energy have small differences according to the local mountainous terrain and residential area. The maximum bias have up to 20% and 16% in Seoul and Eunpyung new town, respectively. Small differences are that limited area with resolutions. As a result, the solar energy can calculate precisely using solar radiation model with topological effect by digital elevation data and its results can be used as the basis data for the photovoltaic and solar thermal generation.

• Journal of the Korean Solar Energy Society
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• v.34 no.3
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• pp.49-56
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• 2014

A fiat-plate or vacuum tube solar collector have been mainly used for hot water supply of house because of some being difficult to get uniform energy density, so little applied into industrial field. This study is to apply the PTC(parabolic trough collector) solar collector into industrial field such as sludge dewatering system for energy reduction. The real scale system which composed of PTC Solar Collector and Thermal Dewatering (TDW) is established. PTC solar collector is designed to produce a hot water with $80^{\circ}C$ of temperature. And size of TDW is $630{\times}630mm$. Hot water produced from PTC solar collector is supplied into heating plate of TDW, and sludge like waterworks or wastewater is dewatered. PTC solar collector with $10m^2$ of area produce energy of average 5,618 kcal. As according to results from real scale performance, solar collector takes charge 94 % of the amount that TDW consume energy which is so large part if compare with boiler. It means that PTC solar collector is useful to apply industrial field under the condition of sufficient solar radiation. And it is analyzed that TDW by PTC solar collector has an economical validity.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.65.2-65.2
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• 2010

The aim of this study was to analysis the Heating/cooling performance of Solar Window built in apartments. The solar window is the idea to integrate daylight as a third form of solar energy into a PV/Solar Collector system and allows more control due to the possibility to close the reflectors. However, there can be a conflict between the desire for on one hand daylight and view and on the other hand optimal energy conversion for the PV/Solar Collector system. The process of this study is as follows: 1) The Solar Window system is designed through the investigation of previous paper and work. 2)The simulation program(ESP-r, Therm5.0, Window6.0) was used in Heating/cooling performance analysis. The reference model of simulation was made up to analysis Heating/cooling performance on Solar Window. 3)Selected reference model(Floors:15, Area of Unit:$148.5m^2$) for heating energy analysis, Energy performance simulation with various variants, such as U-value of Solar Window system according to its position and angle. Consequently, When Solar Window system is equipped with balcony window of Apartment, Annual heating and cooling energy of reference model was cut down about 5%~11%.

• Journal of the Korean Solar Energy Society
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• v.26 no.1
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• pp.7-12
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• 2006

The dish type solar thermal concentrating system can collect the solar energy above $800^{\circ}C$. It has a concentration ratio of 800 and total reflector area of $49m^2$. To operate solar receivers at high temperature, the optimum aperture size is obtained from a comparison between maximizing absorbed energy and minimizing thermal losses. The system efficiency is defined as the absorbed energy by working fluid in receiver divided by the energy coming from the concentrator. We find that system efficiency is stable in case of flow rate of above 6lpm. The system efficiency are 64.9% and 65.7% in flow rate of 6lpm and 8lpm, respectively. The thermal performance showed that the maximum efficiency and the factor of thermal loss in flow rate of 8lpm are 68% and 0.0508.

• Journal of the Korean Solar Energy Society
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• v.31 no.2
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• pp.99-106
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• 2011

Since the solar energy resource is the main input for sizing any solar photovoltaic 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 23 different stations over the South Korea from 1982 to 2009. The Result of analysis shows that the annual-average daily global radiation on the horizontal surface is 3.56 kWh/ $m^2$/day and estimated solar radiation fluxes show reliable results for estimating the global radiation with average deviation of -7.27 to +3.65% from the measured values.

• Journal of the Korean Solar Energy Society
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• v.31 no.4
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• pp.41-47
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• 2011

The volumetric solar receiver is a key element of solar power plants using air. The solar flux distribution inside the receiver should be a priori known for its heat transfer analysis. Previous works have not considered characteristics of the solar flux although they change with radiative properties of receiver materials and receiver geometries. A numerical method, which is based on the Monte Carlo ray-tracing method, was developed in the current work. The solar flux distributions inside multi-channeled volumetric solar receivers were calculated when light is concentrated at the KIER solar furnace. It turned out that 99 percentage of the concentrated solar energy is absorbed within 15mm channel length for the channel radius smaller than 1.5mm. If the concentrated light is assumed to be diffuse, the absorbed solar energy at the channel entrance region is over predicted while the light penetrates more deeply into the channel. Once the presented results are imported into the heat transfer analysis, one could examine effects of material property and geometry of the receiver on air temperature profiles.

• Progress in Superconductivity and Cryogenics
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• v.13 no.1
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• pp.22-26
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• 2011

As new one of superconducting power supplies, we proposed an HTS flux pump utilized a solar energy system. As an eternal electric energy can be converted by the solar system, the solar energy system is promisingly applied as an energy source in the power applications. Especially, since the solar energy system played a role in conventional utility power, total power consumption of the flux pump system are provided by solar energy. That means its operating efficiency is remarkably improved compared with developed flux pumps. A solar energy system is comprised of solar panel, photo-voltaic (PV) controller, converter and battery. The HTS flux pump consists of an electromagnet, two thermal heaters and a Bi-2223 magnet. In this paper, we describe the possibility the fusion technology between superconducting power supply and solar energy system. As a fundamental step, the fabrication, structure and experimental results are explained.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.694-694
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• 2013

With the growing need of more effective energy harvesting, solar energy has been sought as one of the prominent candidates among the eco-friendly methods. Although many types of solar cells have been developed, the electronic conversion efficiency is limited by the material's physical properties: solar cells can only harvest solar energy from limited range in solar energy spectrum. To overcome this physical limit, we approached by using the down conversion effect, transforming the high energy photons to low energy photons, to the range the designated solar cell can convert to electronic energy. In our study, we have fabricated GaAs single junction solar cells and applied CdSe quantum dots for down-conversion. We examine the effects of such application on the solar cell efficiancy, fill-factor, JSC, VOC, etc.

• New & Renewable Energy
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• v.16 no.1
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• pp.41-46
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• 2020

The share of agrophotovoltaics in the "renewable energy 3020", which is the Korean government policy for revitalizing new and renewable energy, is increasing gradually. In this study, the distribution of solar radiation received by crops growing on virtual farmland under a range of conditions, such as module height, module angle, shading ratio, and module type, was quantified and analyzed using an Ecotect program, which allows insolation analysis during the period from spring to fall. As the module angle increases, transmissive modules increase the amount of solar radiation delivered to the lower farmland. In addition, the difference between 3x12 Cell Type and 4x9 Cells Type, which are types of photovoltaic modules used in practice, was found to be small. The analysis results can be used as a design standard for the future establishment of agrophotovoltaic systems.

• Journal of the Korean Solar Energy Society
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• v.31 no.6
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• pp.103-110
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• 2011

The aim of this study was to analysis the Heating/cooling performance and Daylighting performance of Solar Window System built in apartments. the solar window is the idea to integrate daylight as a third form of solar energy into a PV/Solar Collector system. The process of this study is as follows: 1)Solar Window system was designed through the investigation of previous paper and work. 2)The simulation program(Lightscape3.2) was used in daylighting performance analysis. the reference model of simulation was made up to analysis daylighting performance on Solar Window system. 3)The simulation program(ESP-r, Therm5.0, Window6.0) was used in energy performance analysis. the reference model of simulation was made up to analysis energy and daylighting performance on Solar Window system. 4)The Size of Simulation model for daylighting and heating/cooling energy analysis was $148.5m^2$ 5)The lighting performance analysis was carried out with various variants, such as the size and installed area of Solar Window system. 6)Energy performance simulation was carried out with various variants, such as Integrated U-value of Solar Window system according to its position, installed angle and insulation thickness. Consequently, When Solar Window system is equipped with balcony window of Apartment, Annual heating and cooling energy of reference model was cut down at the average of $4.1kWh/m^2$ or 4.2%.