• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.25-26
• /
• 2007

In this paper, we studied the shadow effect which is one of environmental cause for hot-spot phenomenon on PV by considering electrical effects. We fabricated PV module in case of existence and nonexistence of bypass diode. And maximum output power and thermal distribution was analyzed by shadowing solar cell by increase of 5%. From the results, the PV module's(without bypass diode) maximum output power was reduced by hot-spot gradually. But the PV module's(with bypass diode) maximum output power had no reduction by operation of bypass diode, though solar cell is shadowed more than 60%. The solar cell temperature of PV module(without bypass diode) was $10^{\circ}C$ higher compared to module's one. This is a reason for shortening of durability of PV module.

• 한국태양에너지학회:학술대회논문집
• /
• 2009.11a
• /
• pp.86-91
• /
• 2009

In this paper, we analyze the Transition of Isc by natural solar spectrum of c-Si and a-Si PV module. Commonly, performance of photovoltaic (PV) module is estimated under the standard test condition (STC). That is, solar irradiance $1kW/m^2$, solar spectrum distribution: AM1 5G, module temperature $25^{\circ}C$ This means it rarely meets actual outdoor conditions. The solar spectrum always changes. So it is rare to fit the standard solar spectrum AM1 5G defined in ASTM G173-03 or IEC 60904-3. Thus spectral response of PV module is different depending on the material. so we estimated the variation of Isc at every minutes by comparing c-Si PV module with a-si PV module for outdoor conditions.

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

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

• Journal of the Semiconductor & Display Technology
• /
• v.17 no.3
• /
• pp.10-16
• /
• 2018

In silicon crystalline PV (Photo Voltaic) industry, PV module or panel electric power is directly related to the companies' profit. Thus, many PV companies have invested and focused on R&D activities to get the higher module power. The main BOM (Bills of Material) on the module consists of PV solar cell, ribbon, EVA (Ethylene-Vinyl Acetate copolymer), glass and back sheet. Based on consistent research efforts on enhancing module power using BOM, there have been increase of around 5 watt per module every year as results. However, there are lack of studies related to enhancing accuracy of measurement. In this study, the enhancing on the metrology is investigated and the improvement shows actually contribution to company's profit. Especially, the measurement issues related to heat and to quasi state of bandgap diagram by EL(Electro Luminescence) are described in this study.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1100-1101
• /
• 2008

After lamination process, Isc is increased by sheet reflection. This paper presents the electrical output characteristics by back sheet reflection. The experiments was conducted by using single crystalline and multi crystalline PV module. The reflection area of single crystalline PV module is larger than multi one due to the difference of solar cell manufacturing. The experiments show that the increased performance ratio of single crystalline PV module output power is 1.55% rather than that of multi crystalline PV module output power is 1.13%. In addition, it is expected that the output power of single one rather than multi-one is increased by the lower temperature when the PV module is installed outside. The results can be reconsidered by the test material and test process. Back sheet used for humidity prevention makes PV module output power increasing.

• New & Renewable Energy
• /
• v.4 no.4
• /
• pp.17-22
• /
• 2008

A low concentrating (< 5X) photovoltaic module with aluminum reflectors is fabricated and evaluated which is designed to reduce the affection of the high temperature to the solar cell modules preventing the efficiency lowering. As results, the output power is increased of 1.97X from the concentrating photovoltaic module which is designed with the concentrating ratio of 2.25X and to control the module temperature cooling the module by air circulation. Also, the effect of the concentrating module with aluminum reflectors on the conventional PV module is investigated at the field. The result shows the increase of the output power more than about 20% and the improvement of the module efficiency of 1.4X in spite of the increase of average module temperature.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2011.05a
• /
• pp.48.1-48.1
• /
• 2011

In this presentation, We monitored weather data, such as global irradiance, ambient temperature, temperature of PV module, relative humidity and windspeed for 2 years, for determining accelerated test condition. then, we determined the temperature limit of accelerated test through weather data and FEM analysis. Detailed procedures will be summarized in this work. After analysing outdoor stress such as thermal stress, we decided main failure modes and mechanisms of PV module, especially solder joint of ribbon wire. we carried out the measurement of material properties such as thermal expansion coefficient for planning of accelerated test. we designed accelerated test based on FEM analysis results. we carried out thermal cycling test with 1 cell mini module for 3 months. We monitored the change of electrical performance every 1 week such as Voc, Isc, Pmax, etc. and then, we analized the ribbon wire/electrode intefaces. Detailed results will be summarized in this work.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.3
• /
• pp.365-370
• /
• 2013

Generally, photovoltaic modules consist of glass, EVA, Solar Cell, back sheet and ribbon. But EVA, solar cell, ribbon affect electric output with temperature. EVA is a change in the transmittance of light from the sun. In addition, the solar cell output is decreased with temperature and the ribbon increases resistance. Transmittance and reflectance of glass and EVA were measured. In this paper, the characteristics of the components of PV module as EVA and Glass, ribbon were studied by variable temperature. effects on material properties investigated. As a result, glass is independent in temperature variation. EVA was the reduction 1~4% in transmittance. Solar cell decrease 0.469[%/$^{\circ}C$] in electric output by temperature variation. Other factors was controlled in solar cell..

• 한국태양에너지학회:학술대회논문집
• /
• 2008.11a
• /
• pp.42-47
• /
• 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.