• 신재생에너지
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• 제7권2호
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• pp.10-17
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• 2011

Korea is the 11th largest energy consumption country and 96% of its total energy consumption depends on imports from overseas. Therefore it is a very important task to secure renewable energy sources which can reduce both the carbon-dioxide emission and dependency on overseas energy imports. Among the various renewable energy sources, organic wastes are important sources. In Korea, 113 million toe of methane is generated from organic wastes annually, but only 3.7% is effectively used for energy conversion. Thus, it is very important to make better use of organic wastes, especially for power generation. The goals of this project are to develope the fuel supplying system of Bio Gasturbine (GT) for 5MW-class co-generation system. The fuel supplying system mainly consists of $H_2S$ removal system, Bio Gas compression system, Siloxane removal system and moisture separating systems. The fuel requirement of 5MW-class GT is at around 60% of $CH_4$, $H_2S$ (<30 ppm), Siloxane(<10 mg/$nm^3$) and supply pressure (> 25 bar) from biogas compressor. Main mechnical charateristics of Bio Gasturbine system have the specific performance; 1) high speed turbine speed (12,840 rpm) 2) very clean emmission NOx (<50 ppm) 3) high efficiency of energy conversion rate. This paper focuses on the development of design technology for food waste biogas pretreatment system for 5MW-class biogas turbine. The study also has the plan to replace the fuel of gas turbine and other distributed power systems. As the increase of bioenergy, this system help to contribute to spread more New & Renewable Energy and the establishment of Renewable Portfolio Standards (RPS) for Korea.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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• pp.281-286
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• 2008

Current feed-in tariffs(FIT) of Electricity generating from new and renewable energy sources are reappraised with the corrected formula of levelized generation cost(LGC) of utility power. The LGC of new and renewable electricity should be formulated in explicitly reflecting the capital cost and corporate tax during the economic life cycle based on its realistic application data. An applicable term of the FITs should, especially, be equal to the economic life cycle. The revised FITs issued in 2006 were, however, derived from the incorrect formula described in the study of KERI(Korea Electrotechnology Research Institute), and consequently misestimated. The reappraisal values for FIT of new and renewable electricity were shown and interpreted in this paper. An FIT of PV more than 30 kW, for example, should be 972.86 won/kWh instead of current 677.38 won/kWh increasing 43.6%. An upward revision of other FITs for new and renewable electricities should also be required in the range of 8.6% to 47.3%.

• 신재생에너지
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• 제20권1호
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• pp.88-94
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• 2024

This study explored the potential and implementation of renewable energy sources in Sri Lanka, focusing on the theoretical potential of solar and wind energy to develop self-reliant energy models. Using advanced climate data from the European Centre for Medium-Range Weather Forecasts and Global Solar/Wind Atlas provided by the World Bank, we assessed the renewable energy potential across Sri Lanka. This study proposes off-grid and minigrid systems as viable solutions for addressing energy poverty in rural regions. Rural villages were classified based on solar and wind resources, via which we proposed four distinct energy self-reliance models: Renewable-Dominant, Solar-Dominant, Wind-Dominant, and Diesel-Dominant. This study evaluates the economic viability of these models considering Sri Lanka's current energy market and technological environment. The outcomes highlight the necessity for employing diversified energy strategies to enhance the efficiency of the national power supply system and maximize the utilization of renewable resources, contributing to Sri Lanka's sustainable development and energy security.

• 신재생에너지
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• 제4권3호
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• pp.23-35
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• 2008

In the present study, performances of fuel cell driven compound source hybrid heat pump system applied to a large community building are simulated. Among several renewable energy sources, ground, river, sea, and waste water sources are chosen as available alternative energies. The performance and energy cost are varied with the hybrid heat pump sources. The system design and operation process appropriate for the surrounding circumstance guarantee the high benefit of the heat pump system applied to a large community building. Th system is driven by fuel cell system instead of the late-night electricity due to the advantages of the low energy cost and waste heat with high temperature.

• Advances in Energy Research
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• 제5권2호
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• pp.107-128
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• 2017

Energy is a major component of almost all economic, production, and service activities, and rapid population growth, urbanization and industrialization have led to ever growing demand for energy. Limited energy resources and increasingly evident environmental effects of fossil fuel consumption has led to a growing awareness about the importance of further use of renewable energy sources in the countries energy portfolio. Renewable hydrogen production is a convenient method for storage of unstable renewable energy sources such as wind and solar energy for use in other place or time. In this study, suitability of 25 cities located in Iran's western region for renewable hydrogen production are evaluated by multi-criteria decision making techniques including TOPSIS, VIKOR, ELECTRE, SAW, Fuzzy TOPSIS, and also hybrid ranking techniques. The choice of suitable location for the centralized renewable hydrogen production is associated with various technical, economic, social, geographic, and political criteria. This paper describes the criteria affecting the hydrogen production potential in the study region. Determined criteria are weighted with Shannon entropy method, and Angstrom model and wind power model are used to estimate respectively the solar and wind energy production potential in each city and each month. Assuming the use of proton exchange membrane electrolyzer for hydrogen production, the renewable hydrogen production potential of each city is then estimated based on the obtained wind and solar energy generation potentials. The rankings obtained with MCDMs show that Kermanshah is the best option for renewable hydrogen production, and evaluation of renewable hydrogen production capacities show that Gilangharb has the highest capacity among the studied cities.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.858-864
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• 2017

This study aims to restrain free conducting wire-type particles which are commonly and dangerously existing within DC gas-insulated transmission lines. A realistic platform of a coaxial cylindrical electrode was established by using a high-speed camera and a partial discharge (PD) monitor to observe the motion, PD, and breakdown of these particles. The probabilities of standing or bouncing, which can be affected by the length of the particles, were also quantitatively examined. The corona images of the particles were recorded, and particle-triggered PD signals were monitored and extracted. Breakdown images were also obtained. The air-gap breakdown with the particles was subjected to mechanism analysis on the basis of stream theory. Results reveal that the lifting voltage of the wire particles is almost irrelevant to their length but is proportional to the square root of their radius. Short particles correspond to high bouncing probability. The intensity and frequency of PD and the micro-discharge gap increase as the length of the particles increases. The breakdown voltage decreases as the length of the particles decreases.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.1891-1899
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• 2014

A reliability model of wind farm located in mountainous land with complex terrain, which considers the cable and wind turbine (WT) failures, is proposed in this paper. Simple wake effect has been developed to be applied to the wind farm in mountainous land. The component failures in the wind farm like the cable and WT failures which contribute to the wind farm power output (WFPO) and reliability is investigated. Combing the wind speed distribution and the characteristic of wind turbine power output (WTPO), Monte Carlo simulation (MCS) is used to obtain the WFPO. Based on clustering algorithm the multi-state model of a wind farm is proposed. The accuracy of the model is analyzed and then applied to IEEE-RTS 79 for adequacy assessment.

• International Journal of Computer Science & Network Security
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• 제24권1호
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• pp.31-44
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• 2024

People have been using more energy in the last years. Several research studies were conducted to develop sustainable energy sources that can produce clean energy to fulfill our energy requirements. Using renewable energy sources helps to decrease the harm to the environment caused by conventional power plants. Choosing the right location and capacity for DG-RESs can greatly impact the performance of Radial Distribution Systems. It is beneficial to have a good and stable electrical power supply with low energy waste and high effectiveness because it improves the performance and reliability of the system. This research investigates the ideal location and size for solar and wind power systems, which are popular methods for producing clean electricity. A new artificial intelligent algorithm called Nutcracker Optimization Algorithm (NOA) is used to find the best solution in two common electrical systems named IEEE 33 and 69 bus systems to examine the improvement in the efficiency & reliability of power system network by reducing power losses, making voltage deviation smaller, and improving voltage stability. Finally, the NOA method is compared with another method called PSO and developed Hybrid Algorithm (NOA+PSO) to validate the proposed algorithm effectiveness and enhancement of both efficiency and reliability aspects.

• 한국태양에너지학회 논문집
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• 제32권5호
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• pp.75-82
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• 2012

This study aims to investigate the usage of the renewable energy systems installed in buildings and make suggestions for the effective management. In this regard, a questionnaire survey was conducted on 1)design and construction, 2) operation and management, 3) user satisfaction and improvements about the renewable energy systems in buildings. Findings from this study can be summarized as follows; a lack of the basic information about systems, non-use of energy management systems, the differences in the features by energy source, and a lack of expertise of managers. The requirements to resolved these problems include the integrated management of various electric heat sources including a renewable energy source, an operation schedule based on the prediction of production and consumption, and so on. Furthermore the necessity of multiplex energy sources management system was confirmed and the basic data needed to establish the targets of this system were obtained.

• 신재생에너지
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• 제1권3호
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• pp.24-34
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• 2005

Ministry of Commerce, Industry [MOCIE] has taken it into consideration to introduce a Renewable Portfolio Standard (RPS) that is a purchase obligation program as an alternative plan to the FIT. We conducted a survey of renewable energy companies and experts to ask their opinions about renewable energy policy, the introduction of the RPS, and the scheme for aid of North Korea with renewable energy. Korean renewable energy companies show an impartial opinion about a FIT and a RPS system overall, although they tend to have distinctive opinions by technology each other. With respect to eligible resources for a RPS, the industries want to extend the scope of it as broad as possible. In addition, experts prefer the multi-tiered and energy production based RPS to the sing1e-tiered and installed capacity based RPS. We also conducted a surrey to find the best renewable energy sources. Wind, Geothermal, Solar-thermal, and Photovoltaic were selected to have the best potential capacities to support North Korea by renewable energy experts. However, these energy resources also have several problems to overcome in the aid of North Korea, and thus, the plans for solving them and for giving efficient support to North Korea in the area of Renewable Energy are discussed.