• Journal of the Korean Solar Energy Society
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• v.35 no.4
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• pp.57-66
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• 2015

BIPV system not only produces electricity at building, but also acts as a material for building envelope. Thus, it can increase the economical efficiency of PV system by saving the cost for building materials. Bifacial solar cell can convert solar energy to electrical energy from both sides of the cell. In addition, it is designed as 3 busbar layout which is the same with ordinary mono-facial solar cells. Therefore, many of the module manufacturers can easily use the bifacial solar cells without changing their manufacturing equipments. Moreover, bifacial PV system has much potential in building application by utilizing glass-to-glass structure of PV module. However, the electrical generation of the bifacial PV module depends on the characteristics of the building surface which faces the module, as well as outdoor environment. Therefore, in order to apply the bifacial PV module to building envelope as BIPV system, its power generation characteristics are carefully evaluated. For this purpose this study focused on the electrical performance of the bifacial BIPV system through the comparative outdoor experiments. As a result, the power generation performance of the bifacial BIPV system was improved by up to 21% compared to that of the monofacial BIPV system. Therefore, it is claimed that the bifacial BIPV system can replace the conventional BIPV system to improve the PV power generation in buildings.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.87-92
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• 2011

The heat from PV modules should be removed for better electrical performance, and can be converted into useful thermal energy. A photovoltaic-thermal(PVT)module is a combination of PV module with a solar thermal collector which forms one device that converts solar radiation into electricity and heat simultaneously. The performance of the PV/Thermal combined collector module is directly influenced by solar radiation that also has an effect on PV module temperature. It is also has believe that the energy performance of PV/T collector is related to absorber design as well as PV module temperature. The existing study has been paid to the PV/Thermal combined collector module with circle tube absorbers. The aim of this study is to analyze the experimental performance of the PV/Thermal combined collector rectangular tube absorbers according to solar radiation. The experimental result show that the average thermal and electrical efficiencies of the PVT collector were 43% and14.81% respectively. Solar radiation is one of the most influential factors to determine the energy performance of PVT collector, but from a certain level of solar radiation the PVT collector receives on, its efficiencies began to decrease.

• Journal of the Korean Solar Energy Society
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• v.38 no.2
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• pp.55-66
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• 2018

South Korea aims to shift the 20 percent of electricity supplement from the fossil fuel including the nuclear to renewable energy systems by 2030. In order to realize this agenda in the buildings, the plus energy house is necessary to increase the renewable energy supplement beyond the zero energy house. This paper suggested KePSH (KIER Energy-Plus Solar House) and energy performance of house and renewable energy systems was investigated. The KePSH has the target of generating 40% surplus energy than the conventional house energy consumption. The plus energy house is the house that generates surplus energy from the renewable energy sources than that consumes. In order to minimize the cooling and heating load of the house, the shape design and passive parameters design were conducted. Based on the experimental data of the plug load in the typical house, the total energy consumption of the house was estimated. This paper also suggested renewable energy sources integrated HVAC system using air-source heat pump system. Two cases of renewable energy system integration methods were suggested, and energy performance of the cases was investigated using TRNSYS 17 program. The results showed that the BIPV (building integrated photovoltaic) system (i.e., CASE 1) and BIPV and BIST system (i.e., CASE 2) shows 42% and 29% of plus energy rate, respectivey. Also, CASE 1 can generate 59% more surplus energy compared with the CASE 2 under the same installation area.

• Journal of the Korean Solar Energy Society
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• v.39 no.6
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• pp.83-91
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• 2019

Photovoltaic thermal (PVT) collectors are devices that simultaneously produce electricity and heat. Research on conventional air-type PVT collector focuses on installing baffles to enhance the collector's thermal performance. However, the baffles have pressure drop inside the collector which degrades the thermal performance. Thus, it is necessary to design baffles to smoothen the flow inside the air-type PVT collector. Alternatively, installing perforated baffles in air-type PVT collectors can reduce the collector weight, but parameters such as the diameter of the perforated holes and the height of the perforated plates should be considered. Therefore, the main aim of this study was to analyze thermal characteristics of each variable of perforated baffles installed inside air-type PVT collector. For this purpose, the uniformity of air flow in the collector was compared through NX program, and the resultant heat gain and thermal efficiency of the air-type PVT collector were compared and analyzed. Therefore, the main aim of this study was to analyze thermal characteristics of each variable (Baffle angle, length, height, pitch, perforated ratio) of perforated baffles installed inside air-type PVT collector. For this purpose, the uniformity of air flow in the collector was compared through CFD program, and the resultant heat gain and thermal efficiency of the air-type PVT collector were compared and analyzed. As a result, the maximum outlet temperature was increased by 1.45 times and the heat gain was increased by 193.8 Wth, depending on the perforated baffle plate, compared to the collector without the baffle. The heat transfer performance showed that the maximum internal velocity was 1.61 times higher and the Reynolds number was 1.06 times higher depending on the parameters of the baffle plate.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.4
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• pp.113-118
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• 2019

A solar power plant is a facility that produces electricity. As the risk of fire and electric shock accidents is diversified, the risk of workers, surrounding people, and facilities is increased, preventing safety accidents and promptly responding to safety accidents Is emerging. In light of the necessity of such development, it is necessary to develop a solar power generation management system that can diagnose and maintain the problems of the power generation system in real time by developing technologies for collecting and analyzing the data produced by the solar power generation system As a result, the utilization rate and the maintenance cost can be reduced. In order to do this, it is necessary to accurately predict the solar power generation amount in the present state, to diagnose the abnormality of the current power generation state and to grasp the abnormal position, and to use the model considering economical efficiency when the abnormal position is grasped, And the time and other information should be provided.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.3
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• pp.201-206
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• 2022

Energy harvesting is a concept introduced in 1954 by Bell Labs in the US while conducting research on solar cells that convert sunlight into energy. Such energy harvesting technology is a technology that collects wasted or unused energy in daily life and recycles it as electric power. In particular In the case of a photovoltaic power generation system, energy harvesting can be applied by storing electricity generated by using a battery to reduce power consumption generated by the inverter in the form of loss of power generation in cloudy weather compared to sunny days. Therefore, in this paper, energy harvesting technology is applied in the low sunlight section such as sunrise, sunset, and cloudy weather to improve the amount of power generation by recovering the power that is below the minimum operating voltage of the inverter and dissipated. Accordingly, the research contents were verified through the development of systems and algorithms according to the amount of solar power generation and the development of systems and algorithms using low power generated in sunset, sunrise, and other environments.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.4
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• pp.358-368
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• 2023

The fuel cell market is expected to grow rapidly. Therefore, it is necessary to scale up fuel cells for buildings, power generation, and ships. A multi-stack system can be an effective way to expand the capacity of a fuel cell. Multi-stack fuel cell systems are better than single-stack systems in terms of efficiency, reliability, durability and maintenance. In this research, we developed a residential fuel cell stack and system model that generates electricity using the fuel cell-photovoltaic hybrid system. The efficiency and hydrogen consumption of the fuel cell system were calculated according to the three proposed power distribution methods (equivalent, Daisy-chain, and optimal method). As a result, the optimal power distribution method increases the efficiency of the fuel cell system and reduces hydrogen consumption. The more frequently the multi-stack fuel cell system is exposed to lower power levels, the greater the effectiveness of the optimal power distribution method.

• Journal of Energy Engineering
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• v.28 no.3
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• pp.65-79
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• 2019

The study attempted to estimate the optimal facility capacity by combining renewable energy sources that can be connected with gas CHP in industrial complexes. In particular, we reviewed industrial complexes subject to energy use plan from 2013 to 2016. Although the regional designation was excluded, Sejong industrial complex, which has a fuel usage of 38 thousand TOE annually and a high heat density of $92.6Gcal/km^2{\cdot}h$, was selected for research. And we analyzed the optimal operation model of CHP Hybrid System linking fuel cell and photovoltaic power generation using HOMER Pro, a renewable energy hybrid system economic analysis program. In addition, in order to improve the reliability of the research by analyzing not only the heat demand but also the heat demand patterns for the dominant sectors in the thermal energy, the main supply energy source of CHP, the economic benefits were added to compare the relative benefits. As a result, the total indirect heat demand of Sejong industrial complex under construction was 378,282 Gcal per year, of which paper industry accounted for 77.7%, which is 293,754 Gcal per year. For the entire industrial complex indirect heat demand, a single CHP has an optimal capacity of 30,000 kW. In this case, CHP shares 275,707 Gcal and 72.8% of heat production, while peak load boiler PLB shares 103,240 Gcal and 27.2%. In the CHP, fuel cell, and photovoltaic combinations, the optimum capacity is 30,000 kW, 5,000 kW, and 1,980 kW, respectively. At this time, CHP shared 275,940 Gcal, 72.8%, fuel cell 12,390 Gcal, 3.3%, and PLB 90,620 Gcal, 23.9%. The CHP capacity was not reduced because an uneconomical alternative was found that required excessive operation of the PLB for insufficient heat production resulting from the CHP capacity reduction. On the other hand, in terms of indirect heat demand for the paper industry, which is the dominant industry, the optimal capacity of CHP, fuel cell, and photovoltaic combination is 25,000 kW, 5,000 kW, and 2,000 kW. The heat production was analyzed to be CHP 225,053 Gcal, 76.5%, fuel cell 11,215 Gcal, 3.8%, PLB 58,012 Gcal, 19.7%. However, the economic analysis results of the current electricity market and gas market confirm that the return on investment is impossible. However, we confirmed that the CHP Hybrid System, which combines CHP, fuel cell, and solar power, can improve management conditions of about KRW 9.3 billion annually for a single CHP system.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.10
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• pp.694-701
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• 2012

The main purpose of this study is to evaluate of backwash system of hydrodynamic separator filter (HSF) with solar powered submerged pumps. It consists of a photovoltaic solar array, control electronics, battery, and two submersible pump powered by a 12 voltage DC motor. The laboratory scale study on treatable potential of micro particles using backwash HSF that was a combined with perlite filter cartridge and backwash nozzles. Since it was not easy to use actual storm water in the scaled-down hydraulic model investigations, it was necessary to reproduce ranges of particle sizes with synthetic materials. The synthesized storm runoff was made with water and addition of particles; ion exchange resin partices, silica gel particles, and commercial area manhole sediment particles. HSF was made of acryl resin with 250 mm of diameter filter chamber and overall height of 800 mm. Four case test were performed with different backwashing conditions and determined the SS removal efficiency with various surface loading rates. The operated range of surface loading rate was about 308~$1,250m^3/m^2/day$. It was found that SS removal efficiency of HSF using two submersible pumps improved by about 18% compared with HSF without backwash. Nonpoint control devices with solar water pumping systems would be useful for backwashing the filter in areas with not suppling electricity and reduce filter media exchange cost.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.4
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• pp.1-13
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• 2015

The interest in renewable energy which can reduce greenhouse gas emissions has risen in the world including Korea. In Korea, solar energy generation accounts for a major percentage of electricity production using renewable energy and the solar power plants have been increasingly installed in Korea. The problem is, however, that researches on the location selection of solar power plants are unreasonably insufficient although the photovoltaic technology of the domestic solar power plants has been evolving. Thus, advanced solar energy technology could not be fully used. What is more, the indiscriminate installation of the solar power plants seriously damages the nature environment. In this study, conditions of the power plants location are analyzed in consideration of the social, cultural, environmental, economic factors and the optimum location is selected by visualizing and weighing various factors through the analytic hierarchy process. This study shows that the problem caused by the indiscriminate installation of a solar power plant could be prevented by determining the location after considering the influence of several factors. This paper would be helpful not only for the selection of location for solar plant installation in progress, but also for taking follow-up measures on the existing solar power plants placed wrongly.