• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1165_1166
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• 2009

In recent years, energy prices have soared, which of course have increased costs for railway operators. Simultaneously, the energy market has considerably changed that in most developed countries, it is deregulated, giving railway operators an opportunity to define new ways of using energy. Efficient operation of the railway system is considered as an essential way to energy saving while an efficient management of power level helps to lower the reference subscribed power, giving access to better energy rates. It is studied on the relation between time and force for the energy efficient driving of train in railway when the train is braking according to several slips.

• Journal of the Korean Solar Energy Society
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• v.30 no.5
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• pp.77-84
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• 2010

This paper presents the continuous commissioning process, information on the case study facility, improved system operation, and building energy consumption measures before and after continuous commissioning implementation. Continuous commissioning is an ongoing process to resolve operating problems, improve comfort, optimize energy use and identify retrofits for existing commercial and institutional buildings and central plant facilities. Continuous commissioning process consists of two phases. The first phase is the project development phase and the second phase implements and verifies project performance. Results of a case study show that continuous commissioning implementation can reduce energy costs. The energy reports show the electricity savings of 22% and gas savings of 47% on an average.

• Journal of Information Processing Systems
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• v.11 no.1
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• pp.116-124
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• 2015

Smart grids propose new solutions for electricity consumers as a means to help them use energy in an efficient way. In this paper, we consider the demand-side management issue that exists for a group of consumers (houses) that are equipped with renewable energy (wind turbines) and storage units (battery), and we try to find the optimal scheduling for their home appliances, in order to reduce their electricity bills. Our simulation results prove the effectiveness of our approach, as they show a significant reduction in electricity costs when using renewable energy and battery storage.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.234-235
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• 2013

Recently, interest in renewable energy is rising in rural areas in order to reduce heating and air-conditioning costs which are directly connected to farmhouse income. Thus, in this paper, I study renewable energy supporting projects in rural area: I analyze distribution of the Agriculture & Fishery Energy use Efficiency Project and 1 Million the Green Homes program by using project performance data and the data of Korea Energy Handbook. The results of my analysis of the two programs show that, while annual average increase of the 1 million Green homes prgram is 15.6%, the distribution rate of heating and air-conditioning facilities using geothermal heating and cooling system of the project has decreased by average 37% every year.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.1
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• pp.9-21
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• 2009

As one of the alternative solution for energy and environmental issues such as climate change, energy security, oil price, etc., hydrogen energy has been getting so much attentions these days. This paper analyzed the $CO_2$ emission, costs, and energy consumptions when the hydrogen energy was introduced to transportation, specifically in Sedan sector using the energy system model, MARKAL. As results, 21.5% of $CO_2$ emission in 2040 could be reduced and additional 76 billion dollars will be needed in the high energy price scenario. The amount of energy saving mainly due to the replacement of existing car to hydrogen vehicle was 16% of the final energy consumption in 2040.

• KIEAE Journal
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• v.11 no.3
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• pp.19-30
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• 2011

This study examined apartment residents' energy-lifestyle, and their energy consumption patterns by energy-lifestyle. The major findings are as follow: 1)In order to identify energy lifestyle, three dimensions - value of life, energy consuming behavior and energy awareness - were defined by literature reviews, and each dimension was tested to define components. 2)The scores of the 14 factors that were defined by factor analysis on the three dimensions of the energy lifestyle were subject to cluster analysis, and then lifestyle was categorized into five groups. G1 is very negative, and indifferent to energy waste or saving at home. G2 is passively carrying out energy saving activities at home, only within their comfort. G3 is aware of energy saving, and more actively keeping energy saving behavior in their everyday lives, while they also show energy waste behavior at the same time. G4 is particularly indifferent to energy costs, and presenting energy squandering behaviors. G5 is better aware of energy saving than other groups, and carrying out energy saving behaviors in their everyday lives. This study would be of help to establish energy saving management and education plans in apartments.

• Applied Chemistry for Engineering
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• v.27 no.2
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• pp.171-178
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• 2016

Extensive efforts from all over the world have been made to solve energy problems, such as high oil prices, global warning due to the depletion of oil. Among them, biofuel has been drawing attention as a clean energy, which can replace fossil fuels. However, conventional biofuels were often converted from eatable biomass such as sugar cane, corn and soy which should be replaced with uneatable biomass. In this study, a techno-economical evaluation of the gasification of biomass waste with mixed alcohol synthesis process was performed. Considering available domestic biomass wastes, a 2000 ton/day conversion plant were assumed to produce 533000 L/day ethanol. Also, financial data from previous studies were evaluated and used and economical sensitivities with various operation conditions were established. Economic analysis were conducted by the payback period and internal rate of return (IRR) and net present value (NPV). Sensitivity analyses of raw material costs, initial investment, the major process cost, ethanol price changes and operating costs were all performed.

• Journal of Climate Change Research
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• v.4 no.3
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• pp.245-254
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• 2013

Korea government promote renewable energy as the core of their energy matrix to break the dependence and reduce greenhouse effects. This study analyzes the economic assessment of Solid Refuse Fuel project in urban area, considering the marginal external costs of air pollution in this area. Assessment index defined as costs (i.e., construction cost, operation cost) and benefit (margin, external cost) data which is located in Sudokwon landfill site. The result indicates that cost-benefit analysis of SRF is calculated as 1.0. In addition, SRF project is very sensitive about electric power selling price, operating cost and labor cost according to inflation rates. This study shows that the sustainability of SRF project is required the government financial support like investment funds as well as policy support. Variability analysis of SRF economic assessment due to renewable energy can be used for making policies in various fields such as waste and public energy field.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.3
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• pp.147-157
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• 2020

With the increasing obligation to reduce greenhouse gas emissions to the building sector, the government has been gradually expanding its obligation to zero-energy buildings since 2020. Since the ZEB certification took effect in 2017, 48 preliminary and main certifications have been completed as of March 2019, and most of them are public buildings or even certified, but have earned Grade 5 of ZEB. This means that compared with the number of annual building permits registered in Korea, the figure is insignificant, and that it receives little if not mandatory. Therefore, this study investigated empirical cases of ZEB additional construction cost and conducted cost benefit analysis according to changes in ZEB additional construction cost based on a preliminary feasibility analysis project recently conducted by the KDI. In addition, considering the public buildings, the social costs were considered, and the cost-benefit analysis method was the same as the KDI's preliminary feasibility analysis method. The analysis shows that if the ratio of ZEB additional construction cost is more than 5 percent, it is analyzed that there is no economic feasibility, and considering that the ratio of additional construction cost in the cases of ZEB in Korea is 17 percent to 38 percent, it will not be easy to obtain ZEB certification in terms of cost. Finally, to narrow these differences in cost and economic aspects, the overseas low energy and ZEB incentive examples proposed measures such as the concept of subsidy payment in Illinois and the compensation of social costs to private ZEB.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.156-161
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• 2011

In case of newly constructed buildings, the construction type is almost Curtain-wall system or large window in building skin. However, these kind of buildings have problems with regulations on building energy efficiency. And national regulations on building energy efficiency limit only the V-factor of window(except infiltration), it is hard to predict energy consumption of Curtain-wall buildings which gain large solar energy in summer. In this study, the influence of LSG(Light to Solar Gain) on energy performance was theoretically analyzed with simulation. LSG is the value of VLT divide SHGC and represents the optical performance of the glass or glazing. The Window & Therm program developed in LBNL was used to analyze window systems and EnergyPlus was used to building energy. Cases of glazing are three types; single coated Low-e clear glazing, tripple coated Low-e clear glazing, tripple coated Low-e tinted glazing. The results of this study are follows; 1) The building energy consumption of Alt-l, 2, 3 were about 300, 253, $259kWh/m^2{\cdot}yr$ respectively. Therefore, improvement of LSG could save the energy up to 16%. 2) The saved energy could be converted 1 billion won as annual benefit of total energy costs 3) SHGC and LSG more influence on cooling energy than heating energy in office buildings.