• Journal of the Korean Solar Energy Society
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• v.36 no.2
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• pp.65-72
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• 2016

PV module is installed in various outdoor conditions such as solar irradiation, ambient temperature, wind speed and etc. Increase in solar cell temperature within PV module aggravates the behaviour and durability of PV module. It is difficult to measure temperature among respective PV module components during PV module operating, because the temperature within PV module depends on thermal characteristics of PV module components materials as well as operating conditions such as irradiation, outdoor temperature, wind etc. In this paper, simulation by using finite element method is conducted to predict the temperature of each components within PV module installed to outdoor circumstance. PV module structure based on conventional crystalline Si module is designed and the measured values of thickness and thermal parameters of component materials are used. The validation of simulation model is confirmed by comparing the calculated results with the measured temperatures data of PV module. The simulation model is also applied to estimate the thermal radiation of PV module by front glass and back sheet.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.60-67
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• 2011

A photovoltaic/thermal(PVT)solar system is the solar technology that allows for simultaneous conversion of solar energy into both electricity and heat. This paper compared the performance of PVT system with a conventional PV module and solar collector and analyzed electrical and thermal efficiency of PVT system in terms of solar irradiance and inlet temperature of the working fluid. Based on the experimental data, thermal and electrical efficiencies of the glazed PVT system were 57.9% and 14.27% under zero reduced temperature condition which were lower by 13.6% than the solar thermal absorber plate and by 0.08% than the PV module respectively. For the unglazed PVT system, it had lower thermal efficiency than the solar thermal absorber plate but higher electrical performance than the PV module due to the cooling effect by the working fluid. However, total efficiency of the glazed PVT system was 72.2% which was higher than combined efficiencies of the solar collector and PV module. Besides, total efficiency of the PVT system would be much higher if calculated based on unit area.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.688-692
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• 2007

Solar thermal power generation allows additional benefits of cheap thermal storage and easy hybridization with other fossil fuel-driven power generation. KIER has been performing the project for solar thermal chemical reaction hybrid power generation. The project is to build and operate the first solar thermal chemical reaction hybrid power generation system in Korea. For concentrating solar thermal energy $m^2$ dish type concentrator was adapted and a heliostat is installed for reflecting horizontal insolation to the dish concentrator. At the moment building the dish concentrator including mirror and heliostat with sun tracking system was completed and it's performance are being closely evaluated. This paper will introduce some detailed designs and construction procedures which we have experienced so far.

• Journal of the Korean Solar Energy Society
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• v.35 no.3
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• pp.73-79
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• 2015

In this study, a thermal storage performance and characteristics of daily operation were investigated when the air and the liquid were heated simultaneously by a hybrid solar air-water heater that can make hot water as well as heated air. The hybrid solar air-water heater is kind of a flat plate solar collector that can make hot water and heated air by installing air channel beneath absorber plate of traditional flat plate solar collector for hot water. As a result of daily operation, maximum water temperature reached in a thermal storage was shown $44^{\circ}C$ on 73kg/h of air mass flow rate and about $40^{\circ}C$ on 176kg/h of air mass flow rate. Thus, the necessity of heating water in thermal storage by operating only liquid side was confirmed when the temperature of liquid in thermal storage is lower than we need. In case of efficiency investigated on daily operation, the thermal efficiency of the liquid side was decreased with increment of the inlet liquid temperature and decrement of the solar radiation, but efficiency of the air side was increased with increment of inlet liquid temperature difference as the traditional solar air heater. Total thermal efficiency of the collector was shown from 65.85% to 78.23% and it was decreased with increment of the inlet liquid temperature and decrement of solar radiation same as the traditional system.

• New & Renewable Energy
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• v.20 no.1
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• pp.61-69
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• 2024

This study investigates the barriers to the deployment of solar thermal and ground source heat pump (GSHP) from the perspective of consumers and businesses, as well as evaluates priorities for improving the barriers via expert AHP evaluation. From a consumer's perspective, the overall satisfaction with solar thermal is significantly lower than that with PV and needs to be improved at the installation and use stages. GSHP needs to be improved at the prior-information search stage. From a business perspective, the non-distinction between heat and electricity in mandatory installations in public buildings, the difficulty in assessing the value of heat, and high initial costs impede the deployment. Based on the result of AHP analysis, the priorities for improving the barriers to the wide utilization of solar thermal are evaluated in the order of economic feasibility, policy, acceptability, and technology, where high installation cost is shown to be the greatest barrier. Barriers for GSHP are evaluated in the order of policy, acceptability, economic feasibility, and technology, where policy means improvement is evaluated as the most important factor in promoting the deployment of GSHP.

• Journal of the Korean Solar Energy Society
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• v.27 no.3
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• pp.143-148
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• 2007

It is essential to know the flow characteristics at the risers of Flat-plate solar collector for optimum design. For flat-plate solar collector, it is difficult to experimentally study the effect for the number of riser in the collector for the economic problem. So, this study was performed to show the flow characteristics of flat-plate solar collector with the number of riser using commercial code FLUENT 6.0. The base collector size is chosen with $2\;m^2$ as 1m by 2m in this study, the mass flow rate was estimated 0.04 kg/s using the mass flow rate of 0.02 kg/s per collector area for the certificate test. The number of riser is selected 4, 6, 8, 10, 12, and 14. Through the simulation, the conditions with the risers of 10 or 12 is shown as the optimum design conditions for conventional flat-plate solar collector considering lower pressure drop and more uniformly distributed mass flow rate for higher heat transfer rate without considering heat transfer.

• Solar Energy
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• v.18 no.2
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• pp.1-17
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• 1998

In order to analyze the status of development of solar thermal technology in Korea, importance and characteristics of solar thermal technology is considered. That is, solar collector, solar hot water heater, solar industrial system and solar buildings is analyzed in the view of worldwide technology, And then, domestic insolation sources and sale amounts of solar system is introduced. In this paper, it Is presented long-term objective in the basic plan of development new & rowable energy in Korea. As a result of analysis, the status of solar thermal technology in Korea is pactical use state in the field of low temperature use and application state in the field of mid-temperature use.

• Journal of Biosystems Engineering
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• v.16 no.4
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• pp.399-407
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• 1991

In Korea, the cultivation area under the plastic greenhouse was 1,746 ha in 1975, and 36,656 ha in 1989, it shows that the greenhouse cultivation area was increased by 21 times during last 14 years. The greenhouse cultivation area of 90~93% has been kept warm with double layers of plastic film and thermal curtain knitted with rice straw, and the rest area of 7~10% has been heated by fossil fuel energy. The use of rice straw thermal curtain is inconvenient to put it on and off, on the other hand the use of fossil fuel heating system results in the increase of production cost. To solve these problems, at first the heating load and the storable solar energy in greenhouse during the winter season were predicted to design solar utilization system, secondly a solar thermal storage system filled with latent heat storage materials was developed in this study. And then finally the thermal performance of greenhouse-solar energy storage system was analyzed theoretically and experimentally.

• Solar Energy
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• v.9 no.2
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• pp.14-21
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• 1989

The heat transfer analysis is performed on unloaded solar utilization dryer, and thermal performance for a prototype model while drying red-pepper is also investigated. Results of theoretically derived thermal equations are in good agreement with experimental data. This constructed feature of the prototype demonstrates the excellent technical drying performance. Finally, this paper recommends the further work to develop advanced and economic solar utilization multi-purpose dryer.

• 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.