• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.214-219
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• 2011

Today, various activities to save energy are being conducted around the world. Even in our country, carbon reduction policy is being conducted for low carbon green growth and with this movement, effort to replace energy sources by recognizing the problems on environment pollution and resource exhaustion due to the indiscrete usage of fossil fuel is being made. Therefore, active study on renewable energy is in progress as part of effort to replace the energy supply through fossil fuel and solar ray industry has rapidly developed receiving big strength of renewable energy policies. The conclusion of this study measuring the surface temperature change of single crystal and polycrystalline PV module in green roof system and non-green roof system aspect are as follows. There was approximately $4^{\circ}C$ difference in PV module temperature in green roof system and non-green roof system aspect and this has the characteristic to decrease 0.5% when the temperature rises by $1^{\circ}C$ when the front side of the module is $20^{\circ}C$ higher than the surrounding air temperature following the characteristic of solar cells. It can be concluded that PV efficiency will be come better when it is $4^{\circ}C$ lower. Also, in result of temperature measurement of the module back side, there was $5^{\circ}C$ difference of PV module installed on the PV module back side and green roof system side on the 5th, $3^{\circ}C$ on the 4th, $2^{\circ}C$ on the 5th to show decreasing temperature difference as the air temperature dropped, but is judged that there will be higher temperature difference due to the evapotranspiration latent heat effect of green roof system floor side as the temperature rises. Based on this data, it is intended to be used as basic reference to maximize efficiency by applying green roof system and PV system when building non-green roof system flat roof.

• 한국태양에너지학회 논문집
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• 제36권4호
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• pp.41-47
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• 2016

A bypass diode is connected in parallel to solar cells with opposite polarity. The advantage of using the bypass diode is circumvented a destructive efforts of hot-spot heating in the photovoltaic(PV) module. In addition, it is possible to reduce a energy loss under the partial shading on the PV module. This paper presents a characteristic of photovoltaic module under partial shading condition and with defective bypass diode by using the experimental data. The results of field testing for each photovoltaic modules, when photovoltaic system which is connected power grid is operating, the inner junction-box temperature of shading photovoltaic module is high $5^{\circ}C$ because of difference of flowing current through into bypass diode. And incase of not operating photovoltaic system, the inner junction-box temperature of module with defective bypass diode is greatly higher than partial shading PV module.

• 한국도로학회논문집
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• 제17권5호
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• pp.33-38
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• 2015

PURPOSES : The purpose of this paper is to investigate the application of thermoelectric technology to concrete structures for harvesting solar energy that would otherwise be wasted. In various fields of research, thermoelectric technology using a thermoelectric module is being investigated for utilizing solar energy. METHODS: In our experiment, a halogen lamp was used to produce heat energy instead of the solar heat. A data logger was used to record the generated voltage over time from the thermoelectric module mounted on a concrete specimen. In order to increase the efficiency of energy harvesting, various factors such as color, architecture, and the ability to prevent heat absorption by the concrete surface were investigated for the placement of the thermoelectric module. RESULTS : The thermoelectric module produced a voltage using the temperature difference between the lower and upper sides of the module. When the concrete specimen was coated with an aluminum foil, a high electric power was measured. In addition, for the power generated at low temperatures, it was confirmed that the voltage was generated steadily. CONCLUSIONS: Thermoelectric technology for energy harvesting can be applied to concrete structures for generating electric power. The generated electricity can be used to power sensors used in structure monitoring in the future.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.13-14
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• 2008

In this paper, we analyze the electrical characteristics of PV depending on distance among solar cells before and after lamination process. From the result, the PV module's maximum power increases about 3.37% when solar cells's distance is 10mm. And the maximum power increases up to 8.42% when solar cells's maximum distance is 50mm. It is assumed that PV module's surface temperature decreases because of increasing distance between solar cells that would give high power generation. Also, short distance between solar cell and frame result in contamination on glass. When considering reduced maximum power caused by contaminant, from that, we can fabricated PV module of lower cost with high performance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1108-1109
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• 2008

To survive in outdoor environments, photovoltaic modules rely on packaging materials to provide requisite durability. We analyzed the properties of encapsulant materials that are important for photovoltaic module packaging. Recently, the thickness of solar cell gets thinner to reduce the quantity of silicon. And the reduced thickness make it easy to be broken while PV module fabrication process. Solar cell's micro cracks are increasing the breakage risk over the whole value chain from the wafer to the finished module, because the wafer or cell is exposed to tensile stress during handling and processing. This phenomenon might make PV module's maximum power and durability down. So, when using thin solar cell for PV module fabrication, it is needed to optimize the material and fabrication condition which is quite different from normal thick solar cell process. Normally, gel-content of EVA sheet should be higher than 80% so PV module has long term durability. But high gel-content characteristic might cause micro-crack on solar cell. In this experiment, we fabricated several specimen by varying curing temperature and time condition. And from the gel-content measurement, we figure the best fabrication condition. Also we examine the crack generation phenomenon during experiment.

• 상하수도학회지
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• 제31권4호
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• pp.339-346
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• 2017

In this study, thermal performance test of VMD module was performed, prior to the construction of the demonstration plant using the vacuum membrane distillation (VMD) module of the capacity of $400m^3/day$ and to the commercialization of the VMD module. For the thermal performance test, the experimental equipment of capacity of $2m^3/day$ was constructed. The permeate flux test and thermal performance test according to feed water conditions such as temperature and flow rate were conducted. The VMD module used in the study was manufactured by ECONITY Co., LTD with PVDF hollow fiber membrane. As a result, the Performance Ratio (PR) of the VMD module showed the maximum value of 0.904 under the condition of feed water temperature of $75^{\circ}C$ and flow rate of $8m^3/h$. PR value of the VMD module using PVDF hollow fiber membrane showed linearly increasing relationship with feed water temperature and flow rate. Also, The permeate flux of the VMD module was analyzed to have maximum value of 18.25 LMH and the salt rejection was 99.99%.

• 한국태양에너지학회 논문집
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• 제33권3호
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• pp.107-113
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• 2013

In this study, three different types of experimental models of BIPV curtain wall units with GIGS modules were built, and their thermal and electrical performances were analyzed. The experimental results showed that the temperature of the rear side of the GIGS module with the application of an insulation in the curtain wall spandrels was higher than a GIGS module standalone by $22^{\circ}C$, which results in a reduction in the power generation of the former by 8 %. On the other hand, when ventilation was applied to the model to improve the power generation performance, the module temperature was observed to be $142^{\circ}C$ lower compared to the enclosed type, and the power generation performance improved by 5 %. It confirmed that the temperature increase in the rear side of the GIGS module with insulation layer reduced the electrical performance of the module. Based on this, it is claimed that providing sufficient ventilation at the GIGS applied spandrels contribute to improve the power generation of the GIGS module.

• Journal of Biosystems Engineering
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• 제37권1호
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• pp.11-18
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• 2012

Purpose: Short-circuit current of a solar module that is widely used as a power source for wireless environmental sensors is proportional to solar radiation although there are a lot of factors affecting the short-circuit current. The objective of this study is to develop a model for estimating solar radiation for using the solar module as a power source and an irradiance sensor. Methods: An experiment system collected data on the short-circuit current and environmental factors (ambient temperature, cloud cover and solar radiation) during 65 days. Based on these data, two linear regression models and a non-linear regression model were developed and evaluated. Results: The best model was a linear regression model with short-circuit current, angle of incidence and cloud cover and its overall RMSE(Root Means Square Error) was 66.671 $W/m^2$. The other linear model (RMSE 69.038 $W/m^2$) was also acceptable when the cloud cover data is not available.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.364-369
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• 2011

Recently, the cases of BIPV(Building-integrated Photovoltaic) have been increased with interest in renewable energy application for buildings. PV System in building can perform a variety of roles as an energy supplier, exterior materials, aesthetic element and etc. To apply PV modules in buildings, various factors should be considered, such as the installation angle and orientation of PV module, shading, and temperature. The temperature of PV modules that are attached to building surfaces especially is one of the most important factors, as it affects both the electrical efficiency of a PV module and the energy load in a building. BIPV modules designed as finished material for spandrels are presented in this paper. The purpose of this study is to analysis on the thermal performance characteristics of BIPV modules. This study dealt with different types of BIPV modules depending on the backside material, such as clear glass and backsheet. The analysis of monitoring data shows that the PV module temperature was closely related to the solar radiation on the BIPV module surface, and the BIPV used at the backside also had an effect on the PV module temperature that in turn determines its thermal performance.

• 전기학회논문지P
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• 제58권3호
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• pp.339-346
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• 2009

Photovoltaic (PV) energy is a renewable and harmless energy which offers many advantages. However, solar energy is an extreme intermittent and inconstant energy source. In order to improve the photovoltaic system efficiency and utilize the solar energy more fully, and the DC current and DC power vary with the irradiation and module temperature, it is necessary to study the characteristics of photovoltaic I-V and P-V according to the external factors. This paper presents the analysis of characteristics of photovoltaic I-V and P-V according to the irradiation and the module temperature. The results show that the DC current and the DC power of the photovoltaic system are increased along with the increasing values of irradiation and module temperature.