• Transactions of the Korean hydrogen and new energy society
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• v.24 no.4
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• pp.282-287
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• 2013

Hydrogen production from water using solar energy is attractive way to obtain clean energy resource. Among the various solar-to-hydrogen production techniques, a combination of a photovoltaic and an electrolytic cell is one of the most promising techniques in term of stability and efficiency. In this study, we show successful fabrication of precursor solution processed CIGS thin film solar cells which can generate high voltage. In addition, CIGS thin film solar cell modules producing over 2V of open circuit voltage were fabricated by connecting three single cells in series, which are applicable to water electrolysis. The operating current and voltage during water electrolysis was measured to be 4.23mA and 1.59V, respectively, and solar to hydrogen efficiency was estimated to be 3.9%.

• Solar Energy
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• v.18 no.2
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• pp.69-89
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• 1998

The measured solar radiation incident on tilted surfaces by all directions has been widely used as important solar radiation data in installing solar collectors, hot water systems, and photovoltaic modules, and in designing solar buildings and houses. To maximize the incident beam radiation, the slope, which is the angle between the plane of the surface in question and the horizontal, and the solar azimuth angles are needed for these solar applied systems. To respond to above needs, a theoretical study with actual measurements on moving route of the sun is carried out. This study focuses on the development of an solar expert system and on the selection of slopes for solar absorber plates in Korea.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.571-575
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• 2002

Generation of electrical energy faces many problems today. Solar power converters were used to convert the electrical energy from the solar arrays to a stable and reliable power source. The object of this paper is to analyze and design DC-DC converters in a solar energy system to investigate the performance of the converters. A DC-DC converter can be commonly used to control the power flow from solar cell to load and to achieve maximum power point tracking(MPPT), DC-AC converter can also be used to modulate the DC power to AC power being applied on common utility load. A DC-DC converter is used to boost the solar cell voltage to constant 360(V) DC link and to ensure operation at the maximum power point tracking, If a wide input voltage range has to be covered a boost converter is required. In this paper, author described that simulation and experimental results of PV system contain solar modules, a DC-DC converter(boost type chopper), a DC-AC converter (3-phase inverter) and resistive loads.

• Journal of the Korean Society of Industry Convergence
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• v.17 no.4
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• pp.227-233
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• 2014

Information presented in this study is intended to inform candidates as they prepare to design and structure the floatovoltaics solar power system. A developed floatovoltaics solar power generation results from the combination of PV plant technology and PV floating technology. This floating-based PV system is a new concept for PV development. The PV floating technology opens new opportunities to give value to unused areas so far while preserving valuable land for more adapted activities. Therefore the land-use conflicts are avoided and the environmental impact is minimized. Therefore the technology offers an interesting opportunity to regions facing on drought during summer time without any negative impact to the eco-system. This study describe the basic components of a floatovoltaics solar power system. A typical system consist of floating system and solar modules, a control device, rechargeable batteries, a load or device and the associated electrical connections. The floating system is specifically designed to keep all metallic components above water leaving only 100% recyclable, closed cell foam filled HDPE plastic floats in contact with the water. As the first case that can maximize the power generation efficiency of PV internationally, it is expected that this study will be utilized as a primary guide for future development of floating type PV system.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.25-30
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• 2011

In this paper, we analyzed the electrical characteristics with Micro-cracks in Photovoltaic module. Micro cracks are increasing the breakage risk over the whole value chine from the wafer to the finished module, because the wafer or cell is exposed to mechanical stress. And The solar cells have to with stand the stress under out door operation in the finished module. Here the mechanical stress is induced by temperature changes and mechanical loads from wind and snow. So, we experimentally analyze the direct impact of micro-cracks on the module power and the consequences after artificial aging. The first step, we made micro-cracks in PV module by mechanical load test according to IEC 61215. Next, PV modules applied the thermal cycling test, because micro-cracks accelerated aging by thermal cycling test, according to IEC61215. Before every test, we checked output and EL image of PV module. As the result of first step, we detected little power loss(0.9%). But after thermal cycling test increased power loss about 3.2%.

• Journal of the Korean Solar Energy Society
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• v.27 no.4
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• pp.105-111
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• 2007

Hybrid PV/Thermal systems consisting of photovoltaic module and thermal collector can produce the electricity and thermal energy. The solar radiation increases the temperature of PV modules, resulting in the decrease of their electrical efficiency. Accordingly hot air can be extracted from the space between the PV panel and roof, so the efficiency of the PV module increases. The extracted thermal energy can be used in several ways, increasing the total energy output of the system. This study describes a basic type of PV/T collector using water. In order to analyze the performance of the collector, the experiment was conducted. The result showed that the thermal efficiency was 17% average and the electrical efficiency of the PV module was about $10.2%{\sim}11.5%$, both depending on solar radiation, inlet water temperature and ambient temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.3-4
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• 2008

Photovoltaic module consists of serially connected solar cell which has low voltage characteristics. But, the other way, the whole current flow of PV module is restricted by lowest current of one solar cell. For the experiment, we make PV module composing the solar cells that have short circuit current difference of 0%, 1%, 3% and 5%. Using Light I-V and Dark I-V measurements, electrical characteristic parameters like Isc(short-circuit current), Voc(open-circuit voltage), Rs(series resistance), Rsh(shunt resistance) are analyzed. PV module of low current characteristics has electrical stress from other modules. And, such a module has a tendency of hot-spot suffering which leads degradation.

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

• Journal of the Korean Solar Energy Society
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• v.30 no.6
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• pp.102-107
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• 2010

a-Si solar cell has relatively dominant drift current when compared with crystalline solar cell due to the high internal electric field. Such drift current make an impact on the PV module in the local shading. In this paper, the a-Si PV module output characteristics of shading effects was approached in terms of process condition, because of the different deposition layer of thin film lead to rising the resistance. We suggested design condition to ensure the long-term durability of the module with regard to the degradation factors such as hot spot by analyzing the module specification. The result shows a remarkable difference on module uniformity for each shading position. In addition, the unbalanced power loss due to power mismatch of each module could intensify the degradation.

• KIEAE Journal
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• v.6 no.3
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• pp.49-56
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• 2006

The roof among the outer surfaces of buildings is an optimum place to install PV since it is the best favorable part in the building to be exposed to day light. Especially, in case of module of BIPV for Roof, it should have essentially the functions of both electricity generation and roof-finish as a construction material. The followings are the results of the study which has analyzed the architectural conditions and applications thereof at the job site. -The aesthetic function of BIPV module is very important because the roof, mostly located at the top of the buildings, is easily recognized and affects outer interior design of the building a lot. -The heat proof of BIPV for Roof could affect the energy consumption through the roof having a wide area. -For architectural condition to the weather, the roof has to ensure the stability of the weather, humidity proof, and airtightness to the wind respectively. -For architectural condition of the structure, endurance by physical power such as stability of both combining and fixing and transfer of load should be ensured. -For residents protection, it has also architectural functions to secure for the space and shield ozone, UV and noxious substances. -Through its practical applications, It is already confirmed that there are various types of BIPV modules overseas and its application has been proved successfully.