• Solar Energy
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• v.18 no.3
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• pp.81-87
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• 1998

Solar energy has been experiencing renewed interest because of the recent economical crisis in Korea. Absorption cooling is one of the promising solar energy utilization technologies. In this study the dynamic performance of a solar driven absorption cooling machine(SDACM) was numerically investigated. The simulated machine is a commercially available water/LiBr single effect absorption chillers driven by hot water from solar collectors. The present study has been directed to investigate the dynamic behavior of a solar cooling system including an absorption chiller, solar collector, a hot water storage tank, fan coil units, and the air-conditioned space. The operation of the system was simulated for 9 hours in varying operation conditions. The variation of temperature and concentration in the system components, and that of heat transfer rates in the system were obtained. It was also found that the room temperature was maintained near the desired value by controlling the mass flow rate of hot water.

• Journal of the Korean Solar Energy Society
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• v.32 no.1
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• pp.32-39
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• 2012

New and renewable energy systems(solar thermal system, photovoltaic system, geothermal system, wind power system) are environmentally friendly technologies and these in South Korea are very important measures to reduce greenhouse-gas(GHG) and to push ahead with Green Growth. The purpose of this paper is to analyze GHG mitigation potential by distribution of solar thermal system in housing sector with bottom-up model called 'Long-range Energy Alternative Planning system'. Business as usual(BAU) was based on energy consumption characteristic with the trend of social-economic prospects and the volume of housing. The total amount of GHG emission of BAU was expected to continuous increase from 66.0 million-ton $CO_{2e}$ in 2007 to 73.1 million-ton $CO_{2e}$ in 2030 because of the increase of energy consumption in housing. The alternative scenario, distribution of solar thermal system in housing sector had GHG mitigation potential 1.54 million-ton $CO_{2e}$ in 2030. The results of this study showed that new and renewable energy systems made a contribution of reducing the use of fossil fuel and the emission of greenhouse-gas in building.

• Journal of the Korean Solar Energy Society
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• v.35 no.6
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• pp.51-60
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• 2015

In statutes on the promotion of distribution of new and renewable energy, which were revised in 2014, daylight system and fuel cell were added in addition to existing new and renewable energy sources. This study, therefore, aimed at setting up targets for the introduction of daylight system and analyzing the installation rate of new and renewable energy which can be provided by daylight system for the aggressive use of daylight system, thereby deducting the optimal combination ratio with other new and renewable energy sources. The results of the study are as follows. First, when a prism-shaped daylight system was installed to a round indoor gymnasium among domestic indoor gymnasiums, out of a supply obligations allotment rate of 15% of new and renewable energy, the rate of daylight system was basically set at 2.5%. Second, therefore, with daylight system coming first, the lacked supply obligations rate was taken up by solar photovoltaic, solar heat and geothermal heat. In addition, using the KRESS Program, economic, technical, environmental and complexity evaluations for the upper 5% was made, deducting the optimal ratio of the system. The results produced the following optimal combination ratios: solar photovoltaic (83.3%) in economic evaluation, solar heat (8.3%) and geothermal heat (75%) in technical evaluation, solar photovoltaic (83.3%) in environmental evaluation, and solar photovoltaic (83.3%, the same as in economic evaluation) in complexity evaluation.

• Current Photovoltaic Research
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• v.7 no.4
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• pp.121-124
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• 2019

In this research, the concept of a salt farm parallel solar power system, which produce salt and electricity at the same site, is proposed for the first time in the world. The concept is that large waterproof plates made by interconnected solar modules are installed at the bottom of the salt farm. The pilot system was successfully installed at a sea shore, and verified its feasibility as a solar power plant. For deeper understanding, simulations for power prediction of the system were carried out and compared with the field test results. The power generation of the salt farm parallel system is comparable to conventional solar power plants. The cooling effect by sea water contributes more to the increase in the crystalline silicon photovoltaic module performance than the absorption loss due to sea water by maintaining certain height above the module.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.254-256
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• 2007

The Solar energy is either used as a solar thermal energy or converted to electrical power through power conversion system. The latter method is defined as a solar cell changing the solar energy into the direct electric energy or power conversion that convert the dc power into ac power.For the solar cell to be a practical alternative energy, the study should be focused not only on the solar cell ,but also the power conversion system for common power source. In this study, we get the suitable power to common load ,using Ag Grid DSC(Dye-sensitized solar cell). Our purpose is to achieve the common solar cell power generation system ,using converter and PWM(Pulse width modulation) inverter system controled by DSP.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.777-785
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• 2015

In agricultural systems, significant amount of energy is consumed during irrigation periods. Therefore operating irrigation systems with electrical energy produced by solar energy is very important. It is be possible to operate irrigation systems which have small-pump power like drip-irrigation with electrical energy produced by solar energy. Electrical energy produced by photovoltaic panels can vary from the estimated value due to environmental factors. Consequently analysis of a real system's performance is important. Thus, more correct projections can be made for the systems which will be designed. In this study, induction motor-pump mechanism for drip-irrigation system is operated with photovoltaic generator. Solar energy capacity of the established system is evaluated by measurements in irrigation periods. By means of simulations, power values produced by system and gained from the actual system are compared. Additionally the performance of induction motor is analyzed with the help of the driver system that increases the efficiency and controls the motor. As regards of results, design values of the drip-irrigation systems fed with solar energy in Southeastern Anatolian Regions of Turkey are obtained. Performance results of induction motor controlled with driver are also provided.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.130-133
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• 2012

The Korea Institute of Energy Research(KIER) has began collecting solar radiation components data since January, 1988, and solar radiation classified wavelength data since November, 2008. KIER's solar radiation components and classified wavelength data will be extensively used by concentrating solar energy system users or designers as well as by research institutes.

• 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.

• Journal of Institute of Convergence Technology
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• v.4 no.2
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• pp.27-33
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• 2014

To well design the solar energy system using solar energy, the correlation to calculate solar irradiation is basically needed. So, this study was performed to reveal the relationships between the solar irradiation and four meteorological observation data(dry bulb temperature, relative humidity, sunshine duration, and cloud cover) which are different from previous other researches. And then, we finally proposed the first order non-linear correlation from the measured solar irradiation using four meteorological observation data with MINITAB. To show the deviation of the solar irradiation between measured and calculated, this study compared using the daily total solar irradiance and the maximum peak value. From those results, the calculation error was estimated about maximum 25.4% for the daily total solar irradiance. The error of the solar irradiation between measured and calculated was made from the curve fitting error. So, solar irradiation prediction correlation with higher accuracy can be obtained using 2nd or higher order terms with four meteorological observation data.

• Journal of the Korean Solar Energy Society
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• v.30 no.3
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• pp.33-38
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• 2010

The evaporative desalination system using solar thermal energy would be the efficient and attractive method to get fresh water from brine due to low carbon dioxide generation. In this research the solar desalination system as a heating source of refrigerant R123 in the evaporator was considered. The circulation of refrigerant in the evaporator can reduce the energy consumption of the system, because of using the latent heat of the refrigerant 123 instead of the sensible heat of present hot water. The system was comprised of the single-stage fresh water production unit on the capacity of 1ton/day with shell and tube type evaporator, heaters instead of solar collector to supply the proper heat to refrigerant, and refrigerant and brine circulation systems. Various operating flowrate and temperature ranges were varied in the experiments to get the optimum design data. The results showed that the optimum flow rate of brine feed rate to evaporator was 1.2Liter/min, and the yield of fresh water was increased as higher temperature of feed brine. It was confirmed that the circulation flowrate of heating source of refrigerant was decrease of one fifth of the present warm water system, and very efficient system for solar desalination.