• Korean Journal of Materials Research
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• v.29 no.11
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• pp.703-708
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• 2019

In this study, we investigate the relationship between the peeling behavior of the backsheet of a photovoltaic(PV) module and its surface temperature in order facilitate removal of the backsheet from the PV module. At low temperatures, the backsheet does not peel off whereas, at high temperatures, part of the backsheet remains on the surface of the PV module after the peeling process. The backsheet material remaining on the surface of the PV module is confirmed by X-ray diffraction(XRD) analysis to be poly-ethylene(PE). Differential scanning calorimetry(DSC) is also performed to investigate the interfacial characteristics of the layers of the PV module. In particular, DSC provides the melting temperature($T_m$) of laminated ethylene vinyl acetate(EVA) and of the backsheet on the PV module. It is found that the backsheet does not peel off below the $T_m$ of ethylene of EVA, while the PE layer of the backsheet remains on the surface of the PV module above the $T_m$ of the PE. Thus, the backsheet is best removed at a temperature between the $T_m$ of ethylene and that of PE layer.

• 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.

• 한국태양에너지학회:학술대회논문집
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• 2008.11a
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• pp.21-24
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• 2008

In this paper, we introduce the status of concentration photovoltaic system. Currently, crystalline silicon solar has 90% of total solar market. But in a few years, the concentration solar system is expected to be main one because cost increasement of silicon material is not stabilized unit now. At 2012, it will take 5% of the whole solar market. Less expensive, material requirement and high system efficiency give high driving force for intensive research on concentration system. It is time for us to initiate the basic study and evaluate the long term stability compared to crystalline silicon system. The detail discussion will be shown in the following paper.

• 한국태양에너지학회:학술대회논문집
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• 2008.11a
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• pp.57-62
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• 2008

Building Integrated PV(BIPV) is one of the best fascinating PV application technologies. To apply PV module in building, various factors should be reflected such as installation position, shading, temperature, and so on. Especially the installation condition should be considered, for the generation performance of PV module is changed or the generation loss is appeared according to installation position, method, and etc. This study investigates variation of electrical characteristics of a PV module according to the change of irradiance and temperature. From this experimental study, we confirmed that the irradiance, the temperature variation and the generation performance of a PV module were appeared differently according seasonal variation. Actually the PV module installed in building facade showed high-generation performance in winter.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.115-120
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• 2009

In this paper, we measurement the resistance on the flat wire for PV module. There is some kind of flat wire that has different length and different contact area in the PV module. so we test the resistance on each case for analysis with common connection method. we measurement the electrical output characteristics and phenomenon of PV module that is applied new connetion method. by the result, The fill factor and electrical output characteristics on PV module are analyzed to getting better more then common connection method. Finally we recommend the developed connection method for diminishing of resistance on PV module. It enhance the electrical character more than common connection method.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.263-266
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• 2009

In the photovoltaic applications, MPPT(maximum power point tracking) method is essential due to the non-lineality of photovoltaic output characteristics. To ensure stable tracking response, two sensors are required in conventional popular MPPTs. In modularized PV system as an AC module system, the cost of a sensor can have an effect on entire system cost because a power conditioning device is connected in a PV module. Because only a current sensor is required for proposed MPPT, it is helpful in the cost reduction point of view. In this paper, a novel MPPT using current sensor is proposed In the proposed MPPT, the voltage is derived from sensed current value. The proposed method is verified by simulation results.

• Current Photovoltaic Research
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• v.4 no.3
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• pp.119-123
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• 2016

We discussed various cover glass substrates available for photovoltaic (PV) modules, and investigated the fabrication methods of light trapping structures for the efficiency enhancement of PV modules: wet and dry etching or laser and direct patternings. We also introduced the analysis of haze at etched glass surfaces as a function of wavelength and also presented a anti-reflection coating technology for PV module.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.12
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• pp.1289-1295
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• 2004

In this paper, degradation in field-aged PV modules including degradation of interconnect, discoloration of encapsulant and hot spot have been observed and analyzed. From the results, photovoltaic module installed for 6 years shows around 16 % drop of electrical properties due to the interconnect degradation and PV module passed 18 years has been found to drop of around 20 % mainly by the encapsulant discoloration. Furthermore the difference between low and high temperature of PV array at hot spot goes up to 3$0^{\circ}C$ and it leads to interconnect degradation. On the other hands, the temperature difference was observed to be around 15$^{\circ}C$ at the encapsulant discoloration spot of PV array.

• Current Photovoltaic Research
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• v.6 no.3
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• pp.69-73
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• 2018

PV system is consisted with PV module, inverter and BOS(balance of system). To have robustic operation more than 20 years, the expected and guaranteed durability and reliability of products should be met. Almost components of PV system are qualified through IEC standards at test laboratory. But the qualification certificate of product does not ensure long-term nondefective operation. PV module's expected life time is nowadays more than 20 years and annual maximum power degradation ratio would be less than -1%. But the power degradation ratio is basically based on real data more than several years' record. Developing test method for ensuring annual maximum power degradation ratio is very need because there are many new products every month with new materials. In this paper, we have suggested new test method under continuous artificial light irradiation test condition for analyze expected maximum power drop ratio.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.28-32
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• 2004

In this paper, degradation in field-aged PV modules including degradation of interconnect, discoloration of encapsulant and hot spot have been observed and analyzed. From the results, photovoltaic module installed for 6 years shows around 16% drop of electrical properties due to the interconnect degradation and PV module passed 18 years has been found to drop of around 20% mainly by the encapsulant discoloration. Furthermore the difference between low and high temperature of PV array at hot spot goes up to $30^{\circ}C$ and it leads to interconnect degradation. On the other hands, the temperature difference was observed to be around $15^{\circ}C$ at the encapsulant discoloration spot of PV array.