• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.1
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• pp.97-115
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• 2022

Smart power grid is a user friendly system that transforms the traditional electric grid to the one that operates in a co-operative and reliable manner. Demand Response (DR) is one of the important components of the smart grid. The DR programs enable the end user participation by which they can communicate with the electricity service provider and shape their daily energy consumption patterns and reduce their consumption costs. The increasing demands of electricity owing to growing population stresses the need for optimal usage of electricity and also to look out alternative and cheap renewable sources of electricity. The solar and wind energy are the promising sources of alternative energy at present because of renewable nature and low cost implementation. The proposed work models a smart home with renewable energy units. The random nature of the renewable sources like wind and solar energy brings an uncertainty to the model developed. A stochastic dual descent optimization method is used to bring optimality to the developed model. The proposed work is validated using the simulation results. From the results it is concluded that proposed work brings a balanced usage of the grid power and the renewable energy units. The work also optimizes the daily consumption pattern thereby reducing the consumption cost for the end users of electricity.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.15-20
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• 2008

The objectives of this study are to analyze the energy independence plan and to propose a suitable sewage treatment plant in Korea. The total amount of electricity consumption for public sewage treatment plant was estimated as 1,182 GWh in 2007. It was estimated that total 16 sewage treatment plants with renewable energy systems produced electricity of 15.2 GWh per year, which could replaced 0.8% of total electricity used for sewage treatment. It was found that domestic sewage treatment plants with power generation plants by digestion gas were installed in 7 places and produced electricity of 13 GWh per year. It was also found that the power generation plants by digestion gas were the most cost-effective for sewage treatment out of the renewable energy systems based on the benefit-cost analysis.

• New & Renewable Energy
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• v.17 no.2
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• pp.1-8
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• 2021

We estimated the price range of electricity transactions under the prosumer system, considering the spread of renewable energy and the prospect of introducing a surplus power trading system between power consumers in Korea. The range (min/max) of power transaction prices was estimated by prosumers and consumers who could purchase electricity from utilities if needed. It is assumed that utilities purchased electricity from prosumers and consumers under a Time-of-Use (TOU) rate, trading at a monthly price. The range of available transaction prices according to the amount of power purchased from utilities and the amount of transaction power was also estimated. The price range that can be traded is expected to vary depending on variables such as the TOU rate, purchased and surplus power, levelized cost of electricity, etc.

• Transactions of the Korean hydrogen and new energy society
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• v.15 no.4
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• pp.324-332
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• 2004

According to the rapid depletion of the fossil fuels, the electricity and hydrogen will gradually take charge of the future energy supply. Especially, in order to control the supply and demand of electricity, energy storage medium is necessary and this could be solved by the combination of water electrolysis and fuel cell. Although electricity can be generated from such alternative energies as hydropower, nuclear, solar, and wind-power resources, alternative energy storage medium is also required since regenerative energies, solar and wind-powers, are intermittent energy resources. In this regard, hydrogen production from water electrolysis was recognized as a superb method for electricity storage. In this work, the current development and economic status of alkaline, solid polymer, and high temperature electrolysis were reviewed, and then the practical use of water electrolysis technology were discussed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.6
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• pp.560-568
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• 2005

The cost accounting of electricity and heat produced from an energy system is important in evaluating the economical efficiency and deciding the reasonable sale price. The OECOPC method, suggested by the author, was applied to a 650 MW combined cycle cogeneration system having 4 operating modes, and each unit cost of electricity and heat products was calculated. In case that a fuel cost is ${\\}400/kg$ and there are no direct and indirect cost, they were calculated as follows; electricity cost of ${\\}23,700/GJ$ at gas-turbine mode, electricity cost of ${\\}15,890/GJ$ at combined cycle mode, electricity cost of ${\\}14,146/GJ$ and heat cost of ${\\}6,466/GJ$ at cogeneration mode, and electricity cost of ${\\}14,387/GJ$ and heat cost of ${\\}4,421/GJ$ at combined cycle cogeneration mode. Further, these unit costs are applied to account benefit on this system. Since the suggested OECOPC method can be applied to any energy system, it is expected to contribute to cost accounting of various energy systems.

• International Journal of Computer Science & Network Security
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• v.24 no.6
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• pp.33-40
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• 2024

Introducing renewable energy sources, such as wind and photovoltaic arrays, in microgrids that supply remote regions with electricity represents a significant leap in electricity generation. Combining photovoltaic panels and diesel engines is one of the most common ways to supply electricity to rural communities. Such hybrid systems can reduce the cost of electricity generation in these remote power systems because they use free energy to balance the power generated by diesel engines. However, the combination of renewable energy sources and diesel engines tends to complicate the sizing and control of the entire system due to the intermittent nature of renewable energy sources. This study sought to investigate this issue in depth. It proposes a robust hybrid controller that can be used to facilitate optimum power sharing between a PV power source and diesel generators based on the dynamics of the available PV energy at any given time. The study also describes a hybrid PV-diesel power plant's essential functional parts that produce electricity for a microgrid using a renewable energy source. Power control needs to be adjusted to reduce the cost of power generation.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2004.05a
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• pp.353-358
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• 2004

In recent, the trends in national energy Policy are established in the context of the integrated risk estimation for various national electricity generating options. The approach takes account of health, environmental, economic, and social aspects of electricity generation systems. In the present work, nuclear, coal, and LNG sources are chosen because these hold more than 90% of national total electricity generation in a descending order. A life cycle assessment (LCA) methodology is used for comparing environmental impacts of these options during the life cycle such as construction, operation as well as disposal stages. Here, the LCA consists of life cycle inventory analysis, classification/selection process of impact categories, characterization process, and normalization process of each category. LCA can be an useful tool for environmental impact assessment of future national energy options. At the planning stage of future energy Policies, the results of LCA would be taken into consideration. According to data update at the construction and disposal stages, the LCA needs to be conducted iteratively.

• Korean Journal of Chemical Engineering
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• v.36 no.1
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• pp.12-20
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• 2019

An energy storage system consisting of a battery and a power-to-methanol (PtM) unit was investigated to develop an energy storage system for renewable energy systems. A nonlinear programming model was established to optimize the energy storage system. The optimal installation capacities of the battery and power-to-methanol units were determined to minimize the cost of the energy system. The cost from a renewable energy system was assessed for four configurations, with or without energy storage units, of the battery and the power-to-methanol unit. The proposed model was applied to the modified electricity supply and demand based on published data. The results show that value-adding units, such as PtM, need be included to build a stable renewable energy system. This work will significantly contribute to the advancement of electricity supply and demand management and to the establishment of a nationwide policy for renewable energy storage.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.119-124
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• 2014

After the oil crisis in 1970s, many countries have tried to reduce oil dependency. Especially, in Korea, rapid declining oil consumption has speedily brought to electrification and a surge in electricity demand. This paper attempts to estimate the relationship between declining oil use and electrification in Korea using OECD panel data covering from 1985 to 2011. To this end, random effect model and fixed effect model are employed. The increase in the ratio of energy oil to total energy consumption by 10%p leads to reduce the electricity demand by about 15%. This result can be useful information to cope with the recent crisis of electric power. In addition, industrial sector is ranked in forth the ratio of industrial electricity use to total electricity use according to the result of comparative analysis of electricity consumption by use in OECD countries. Therefore, industrial sector should be treated as the main target of demand-side management policies for electricity.

• Journal of Energy Engineering
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• v.28 no.2
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• pp.1-17
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• 2019

This article analyzes causal relationships among gross domestic product(GDP), electricity consumption, carbon dioxide($CO_2$) emission and foreign direct investments(FDI) inflow of Korea over the period from 1976 to 2014, using unit root test, cointegration test, and vector error correction model(VECM). As the results, this article found (1) a long-run bi-directional causality between GDP and electricity consumption, which may imply a negative impact of electricity consumption-saving policy on economic growth, (2) uni-directional short- and long-run causalities running from $CO_2$ emission to GDP, and a uni-directional long-run causality running from $CO_2$ emission to electricity consumption, which can result in a negative impact of $CO_2$ emission reduction policy on economic growth and electricity consumption, (3) a uni-directional long-run causality running from FDI to GDP, and uni-directional short- and long-run causalities running from FDI to electricity consumption, which may result from relatively lower electricity prices than investing countries, (4) no causality between FDI and $CO_2$ emission, which is based on the characteristics of FDI composed of service industries. Considering the above causal relationships among the four variables, the policy implication needs to focus on the electricity demand management based on the relevant R&Ds, and on the gradual transition from fossil fuel- to renewable-energy. Adaptive policy to increase the FDI inflow is also needed.