• Korean Journal of Materials Research
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• v.29 no.11
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• pp.720-726
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• 2019

Recently, research on cost reduction and efficiency improvement of crystalline silicon(c-Si) photovoltaic(PV) module has been conducted. In order to reduce costs, the thickness of solar cell wafers is becoming thinner. If the thickness of the wafer is reduced, cracking of wafer may occur in high temperature processes during the c-Si PV module manufacturing process. To solve this problem, a low temperature process has been proposed. Conductive paste(CP) is used for low temperature processing; it contains Sn57.6Bi0.4Ag component and can be electrically combined with solar cells and ribbons at a melting point of $150^{\circ}C$. Use of CP in the PV module manufacturing process can minimize cracks of solar cells. When CP is applied to solar cells, the output varies with the amount of CP, and so the optimum amount of CP must be found. In this paper, in order to find the optimal CP application amount, we manufactured several c-Si PV modules with different CP amounts. The amount control of CP is fixed at air pressure (500 kPa) and nozzle diameter 22G(outer diameter 0.72Ø, inner 0.42Ø) of dispenser; only speed is controlled. The c-Si PV module output is measured to analyze the difference according to the amount of CP and analyzed by optical microscope and Alpha-step. As the result, the optimum amount of CP is 0.452 ~ 0.544 g on solar cells.

• Journal of Urban Science
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• v.8 no.1
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• pp.7-14
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• 2019

Recently, interest in solar energy, which is the center of new government energy policy, is increasing. However, the focus is on mass production of solar power plants, and policies and related technologies for maintenance and management of existing installed PV modules are insufficient. In this study, we use UAV (Unmanned Aerial Vehicle) to acquire RGB and infrared images, apply it to the structure-from-motion (SfM) based image analysis tool, model the three- And the position of the hot spot was monitored and coordinates were detected. As a result, it is possible to provide basic spatial information for maintenance of solar module by monitoring and position detection of hot-spot suspected solar cells by superimposing infrared image and RGB image based on unmanned aerial vehicle.

• Journal of Cadastre & Land InformatiX
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• v.49 no.1
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• pp.17-27
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• 2019

In this study, we conducted a study to predict the photovoltaic power by constructing the sensor based meteorological data observation system and the accurate terrain data obtained by using LiDAR surveying. The average sunshine hours in 2018 is 4.53 hours and the photovoltaic power is 2,305 MWh. In order to analyze the effect of photovoltaic power on the installation angle of solar modules, we installed module installation angle at $10^{\circ}$ intervals. As a result, the generation time was 4.24 hours at the module arrangement angle of $30^{\circ}$, and the daily power generation and the monthly power generation were the highest, 3.37 MWh and 102.47 MWh, respectively. Therefore, when the module arrangement angle is set to $30^{\circ}$, the generation efficiency is increased by about 4.8% compared with the module angle of $50^{\circ}$. As a result of analyzing the influence of the seasonal photovoltaic power by the installation angle of the solar module, it was found that the photovoltaic power was high in the range of $40^{\circ}{\sim}50^{\circ}$, where the module angle was large from November to February when the weather was cold. From March to October, it was found that the photovoltaic power amount is $10^{\circ}{\sim}30^{\circ}$ with small module angle.

• KIEAE Journal
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• v.15 no.5
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• pp.83-88
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• 2015

Purpose: Photovoltaic system is a technique for producing electrical power by utilizing solar energy, which can be used over 20 years with simple maintenance. However, in the case of photovoltaic systems, the energy conversion efficiency decreases as the surface temperature of module increases, compared with other renewable energy technologies. In this regard, PVT module can increase the energy utilization of a composite module as producing heat and electricity simultaneously by using solar energy. Currently, many researches have been promoting in order to develop a high efficiency PVT module in Korea. However, there are a few studies about the performance of the modules corresponding the shape of types and various heat exchangers of the PVT module. In this study, the electrical performance was measured by the change of the ambient temperature and the circulating water temperature using the fabricated PVT module. Method: Experiments were performed using a solar simulator. And this experiment was assumed that the weather condition was in each season, as winter, spring, autumn and summer. It was identified that the I-V curve associated with the change of the experimental conditions and confirmed the change in the electrical characteristics. Result: As a result, it was figured out that the surface temperature and the electrical performance changes in case conditions. The electrical performance was calculated in different temperature condition and the power production was confirmed by the change of module temperature.

• Journal of the Korean Society of Safety
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• v.33 no.4
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• pp.1-7
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• 2018

This paper is analyzed for the thermal characteristics(1 year) of the 6 components(DC breaker, DC filter(including capacitor and discharge resistance), IGBT(Insulated gate bipolar mode transistor), AC filter, AC breaker, etc.) of a photovoltaic power generation-based PCS(Power conditioning system) below 20 kW. Among the modules, the discharge resistance included in the DC filter indicated the highest heat at $125^{\circ}C$, and such heat resulting from the discharge resistance had an influence on the IGBT installed on the rear side the board. Therefore, risk priority through risk priority number(RPN) of FMEA(Failure modes and effects analysis) sheet is conducted for classification into top 10 %. According to thermal characteristics and FMEA, it is necessary to pay attention to not only the in-house defects found in the IGBT, but also the conductive heat caused by the discharge resistance. Since it is possible that animal, dust and others can be accumulated within the PCS, it is possible that the heat resulting from the discharge resistance may cause fire. Accordingly, there are two options that can be used: installing a heat sink while designing the discharge resistance, and designing the discharge resistance in a structure capable of avoiding heat conduction through setting a separation distance between discharge resistance and IGBT. This data can be used as the data for conducting a comparative analysis of abnormal signals in the process of developing a safety device for solar electricity-based photovoltaic power generation systems, as the data for examining the fire accidents caused by each module, and as the field data for setting component management priorities.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.12
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• pp.559-564
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• 2014

The development of photovoltaic-thermal (PVT) technology has been introduced in recent years specifically to increase PV efficiency. One of the characteristics of PV systems is that the electricity generation increases as the solar radiation increases whereas the efficiency decreases because of high surface temperatures. Using a photovoltaic-thermal system, the surface temperature can be decreased by capturing the excess heat and the efficiency can be increased due to these characteristics. In this paper, three cases are introduced : 1) PV_r as the reference case, 2) PVT_a, which uses air as a heat source, and 3) PVT_w, which uses water as a heat source. Experiments were performed, analyzed, and compared to examine the effect of the PVT type on the efficiency of the system. The results showed that ETC($%/^{\circ}C$) efficiency of the PVT cases was increased versus the reference case due to decreasing surface temperature. Total efficiencies, which are electrical efficiency and thermal efficiency, for each PVT are tested and found to be 12.22% for PV_r, 29.50% for PVT_a, and 68.74% for PVT_w.

• Journal of the Korean Solar Energy Society
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• v.37 no.4
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• pp.23-33
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• 2017

A great deal of study for loss reduction of photovoltaic system is conducted currently. It is hard to distinct the fault of photovoltaic system with the naked eye. For that reason, it is essential to repair and maintain the PV system by monitoring the system. The fault of individual modules can cause the huge loss of the entire system because of the mismatch. Therefore, the method of diagnosing the PV array is necessary by measuring the multi-channel arrays simultaneously. In this paper, it is presented the method of measuring I-V curve of multi-channel arrays simultaneously by using the charge and discharge characteristics of capacitor. Generated DC power at PV arrays is charged and discharged at the capacitors in a moment. By measuring the charged voltage and current, it is possible to diagnose of performance of PV arrays.

• Current Photovoltaic Research
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• v.7 no.3
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• pp.65-70
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• 2019

As a demand of higher power photovoltaic modules, shingled, multi-busbar, half-cell, and bifacial techniques are developed. Multi-busbar module has advantage for large amount of light havesting. And, half-cell is high power module for reducing resistive losses and higher shade tolerance. Recently, researches on multi-busbar is focused on reliability according to adhesion and intermetallic compound between Sn-Pb solder and Ag electrode. And half-cell module is researched to comparing with full-sized cell module for structure difference. In this study, we investigated the factors affecting to efficiency and adhesion of multi-wires half-cell module according to wire thickness, solder thickness, and flux. The results of solar simulator and peel test was that peel strength and efficiency of soldered cell is not related. But samples with flux including high solid material showed high efficiency. The results of FE-SEM and EDX line scan on cross-section between wire and Ag electrode for different flux showed thickness of solder joint between wire and Ag electrode is increasing through solid material increasing. Flux including high solid material would affect to solder behavior on Ag electrode. Higher solid material occurred lower growth of IMC layer because solder permeate to sider of wire ribbon than Ag electrode. And it increased fill factor for high efficiency. In soldering process, amount of solid material in flux and solder thickness are the factor related with characteristic of soldered photovoltaic cell.

• Current Photovoltaic Research
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• v.9 no.2
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• pp.45-50
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• 2021

Agrovoltaic system is a concept that combines agriculture and photovoltaic (PV) system by applying a PV system to the upper part of farmland. In this study, we developed a folding drive system for an agrophotovoltaic (agroPV) module (150 Wp/4×9 cell) exclusively for pear farming with 10 kW capacity. The system was installed in 2018, and the growth characteristics and quantity of pears under the agroPV folding system have been investigated for 2 years. We found that thare is no differences of the characteristics of pears grown under the agroPV system compared to the pears grown without the system (control) except the percutaneous color L of pear. However, the weight and sugar content of the pear grown under the agroPV system were decreased by 4.5% and 1.3°Bx compared to that of the control, respectively. We assume that this is mainly due to the influenced of the delay in flowering as upper PV module block some of sunlight. However, interestingly, when we deleyed the pear harvesting by 2 weeks, the weight of pears increased by 8.5% and they became nearly the sample as the control pears harvested 2 week earlier. In addition, we also found that the agroPV modules decrease the fall rate of pear when the typoon struck, also it mitigates cold damage by 38% during April by protecting from frost. In conclusion, it can be said that the agroPV system help to protect target crops from the environmental conditions and the quality of the crops are similar to the that of control.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.45-48
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• 2009

This study evaluated the influence of temperature on the PV module surface on power output characteristics, especially for an amorphous transparent thin-film PV module which was applied to a full-scale mock-up model as building integrated photovoltaic system. The tested mock-up consisted of various slopes of PV module, facing to the south. The annual average temperature of the module installed with the slope of $30^{\circ}$ revealed $43.1^{\circ}C$, resulting in $7^{\circ}C$ higher than that measured in PV modules with the slope of $0^{\circ}$and $90^{\circ}$ did. This $30^{\circ}$ inclined PV module also showed the highest power output of 28.5W (measured at 2 PM) than other two modules having the power output of 20.4W and 14.9W in the same time for $0^{\circ}$ and $90^{\circ}$ in the slope, respectively. In case of the $30^{\circ}$ inclined PV module, it exhibited very uniform distribution of power output generation even under the higher temperature on the module surface. Consequently, the surface temperature of the PV module analyzed in this study resulted in 0.22% reduction in power output in every $1^{\circ}C$ increase of the module surface temperature.