• KIEAE Journal
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• v.7 no.1
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• pp.41-48
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• 2007

This research has been carried out to give economical incentives and to promote for the eco-friendly village. A standard model plan for the Korean eco-village has been prepared by systematically applying the results of the research to Boksoo village, which served as an exemplary model. Plans for promoting the Korean eco-village are finally derived after a series of theoretical assessment of conceptual propositions in harnessing natural elements well suited with man-made structures. The eco-friendly village that this study is to develop harnesses natural energy resources and establishes pleasant living environment for human. It minimizes the unjust load against nature and restrains the excessive consumption of irreplaceable indigenous energy and other natural resources on earth. Paraphrasing, the utilization of natural energy resources in the eco-friendly village features various schemes of the related technologies in energy conservation and exploitation of renewable energies including solar thermal, photovoltaic, daylighting, wind power and etc. The eco-friendly village would definitely make our world more healthier than before by suppressing the emission of green house gases from fossil fuels and ever increasing energy consumption.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.762-764
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• 2003

In Korea, over 97% of local energy demand is imported from other countries. And we have to lift the energy independence level up to 5% with replacement energy (renewable energy) such as solar, small hydropower, etc. by 2011 according to the energy agreement made in Kyoto Protocol. So, we proposed some opinions such as the better improvement of small hydropower industry the people' view, cooperation among industry/university/research institutes, remote control/maintenance and goverment's legislature and supporting system etc.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.2
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• pp.44-52
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• 2012

As an alternative strategy in the era of high level petroleum cost, the study focused to suggest the way on the revitalization of renewable energy through the impact on introduction effect of renewable energy in green village. Total feasible solar energy production is 6.73 GWh/yr along with the biomass energy producing electric power energy is 134.06 GWh/yr, the two category's total electric power energy is 233.19 GWh/yr, which is possible to achieve the selfsufficiency of energy by 33% for total energy consumption of 705.80 GWh/yr in the region. The calculated feasibility on the carbon dioxide reduction, carbon dioxide reduction level is 1,891 ton_$CO_2$ by agricultural byproducts, 43,635 ton_$CO_2$ by livestock waste, 395 ton_$CO_2$ by municipal waste, 50,324 ton_$CO_2$ by forest byproducts, the total biomass shows 96,245 ton_$CO_2$, while the carbon dioxide reduction of solar light energy is 2,251 ton_$CO_2$, 1,383.3 ton_$CO_2$ by solar heat energy, the total solar energy shows 3,634 ton_$CO_2$. So total carbon dioxide reduction effect shows 99,879 ton_$CO_2$.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.101-101
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• 2010

Anaerobic digestion(AD) is the most promising method for treating and recycling of different organic wastes, such as organic fraction of municipal solid waste, household wastes, animal manure, agro-industrial wastes, industrial organic wastes and sewage sludge. During AD, i.e. organic materials are decomposed by anaerobic forming bacteria and fina1ly converted to excellent fertilizer and biogas which is a mixture of carbon dioxide and methane. AD has been one of the leading technologies that can make a large contribution to produce renewable energy and to reduce $CO_2$ and other green-house gas(GHG) emission, it is becoming a key method for both waste treatment and recovery of a renewable fuel and other valuable co-products. Currently some 80% of the world's overall energy supply of about 400 EJ per year in derived from fossil fuels. Nevertheless roughly 10~15% of this demand is covered by biomass resources, making biomass by far the most important renewable energy source used to date. The representative biofuels produced from the biomass are bioethanol, biodiesel and biogas, and currently biogas plays a smaller than other biofuels but steadily growing role. Traditionally anaerobic digestion applied for different biowaste e.g. sewage sludge, manure, other organic wastes treatment and stabilization, biogas has become a well established energy resource. However, the biowaste are fairly limited in respect to the production and utilization as renewable source, but the plant biomass, the so called "energy crops" are used for more biogas production in EU countries and the investigation on the biomethane potential of different crops and plant materials have been carried out. In Korea, with steadily increasing oil prices and improved environmental regulations, since 2005 anaerobic digestion was again stimulated, especially on the biogasification of different biowastes and agro-industrial biomass including "energy crops". This study have been carried out to investigate anaerobic biodegradability by the biochemical methane potential(BMP) test of animal manures, different forage crops i.e. "energy crops", plant and industrial organic wastes in the condition of thermophilic temperature, The biodegradability of animal manure were 63.2% and 58.2% with $315m^3CH_4/tonVS$ of cattle slurry and $370m^3CH_4/tonVS$ of pig slurry in ultimate methane yields. Those of winter forage crops were the range 75% to 87% with ultimate methane yield of $378m^3CH_4/tonVS$ to $450m^3CH_4/tonVS$ and those of summer forage crops were the range 81% to 85% with ultimate methane yield of $392m^3CH_4/tonVS$ to $415m^3CH_4/tonVS$. The forge crops as "energy crops" could be used as good renewable energy source to increase methane production and to improve biodegradability in co-digestion with animal manure or only energy crop digestion.

• Journal of Technology Innovation
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• v.18 no.1
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• pp.53-74
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• 2010

The creation and acceptance of new technologies has been speeding up dramatically in modern times. There are also significant uncertainties about the future shape of markets, governance and social values that will have an important impact on organizations and their capacity to meet their objectives. These rapid technological and social change and uncertainties make the upsurge of interest in technology foresight, giving rise to its emergence as a global concept and policy tool. A wide range of future methods are available for technology foresight. Selection of methods will depend upon several factors, most notably available and the time financial resources, and the objectives of the exercise. Although Delphi has been widely used for many years, scenario becomes very popular in recent years. The use of scenarios can take better account of the complexity and unpredictability of the economic, social and political environments. Scenarios tell the stories describing paths to different futures, which help organizations make better decisions today. In this study, the scenario method was employed to draw the images of the future of renewable energy. Renewable energy grows dramatically in recent years. However, there is still considerable uncertainty with regard to the potential of renewable energy due to environment regulation, energy costs, and political and economic developments in the main supplier countries for oil and natural gas. Scenario can help us to identify the risks and opportunities when we develop the renewable energy, and to prepare for them. The scenario method is expected to be more utilized in the national technology foresight.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.4
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• pp.633-642
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• 2021

Growing demand for electricity, when combined with the need to limit carbon emissions, drives a huge increase in renewable energy industry. In the electric power system, electricity supply always needs to be balanced with electricity demand and network losses to maintain safe, dependable, and stable system operation. There are three broad challenges when it comes to a power system with a high penetration of renewable energy: transient stability, small signal stability, and frequency stability. Transient stability analyze the system response to disturbances such as the loss of generation, line-switching operations, faults, and sudden load changes in the first several seconds following the disturbance. Small signal stability refers to the system's ability to maintain synchronization between generators and steady voltages when it is subjected to small perturbations such as incremental changes in system load. Frequency stability refers to the ability of a power system to maintain steady frequency following a severe system upset resulting in significant imbalance between generation and load. In this paper, we discusses these stability using system simulation by renewable energy deployment plan, and also analyses the influence of the renewable energy sources to the grid stability.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.3
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• pp.128-137
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• 2013

Due to the global warming and air pollution, interest in renewable energies has increased in recent years. In particular, the crisis of the depletion of fossil energy resources in the near future has accelerated the renewable energy technologies. Among the renewable energy resources, oceans covering almost three-fourths of earth's surface have an enormous amount of energy. For this reason, various approaches have been made to harness the tremendous energy potential. In order to achieve two purposes: to improve harbor water quality and to use wave energy, this study proposed a sea water exchange structure applying an Oscillating Water Column (OWC) wave generation system that utilizes the air flow velocity induced by the vertical motion of water column in the air chamber as a driving force of turbine. In particular, the airflow velocity in the air chamber was estimated from the time variations of water surface profile computed by using 3D-NIT model based on the 3-dimensional irregular numerical wave tank. The relationship of the frequency spectrums between the computed airflow velocities and the incident waves was analyzed. This study also discussed the characteristics of frequency spectrums in the air chamber according to the presence of the structure, wave deformations by the structure, and the power of the water and air flows were also investigated. It is found that the phase difference exists in the time series data of water level fluctuations and air flow in the air chamber and the air flow power is superior to the fluid flow power.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.1
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• pp.18-28
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• 2014

Renewable Portfolio Standards(RPS) is a regulation that requires a renewable energy generated from eco-friendly energy sources such as biomass, wind, solar, and geothermal. The RPS mechanism generally is an obligatory policy that places on electricity supply companies to produce a designated fraction of their electricity from renewable energies. The domestic companies to supply electricity largely rely on wood pellets in order to implement the RPS in spite of undesirable situation of lack of wood resources in Korea. This means that the electricity supply companies in Korea must explore new biomass as an alternative to wood. Palm kernel shell (PKS) and empty fruit bunch (EFB) as oil palm wastes can be used as raw materials used for making pellets after their thermochemical treatment like torrefaction. Torrefaction is a pretreatment process which serves to improve the properties including heating value and energy densification of these oil palm wastes through a mild pyrolysis at temperature typically ranging between 200 and $300^{\circ}C$ in the absence of oxygen under atmospheric pressure. Torrefaction of oil palms wastes at above $200^{\circ}C$ contributed to the increase of fixed carbon with the decrease of volatile matters, leading to the improvement of their calorific values over 20.9 MJ/kg (=5,000 kcal/kg) up to 25.1 MJ/kg (=6,000 kcal/kg). In particular, EFB sensitively responded to torrefaction because of its physical properties like fiber bundles, compared to PKS and hardwood chips. In conclusion, torrefaction treatment of PKS and EFB can greatly contribute to the implement of RPS of the electricity supply companies in Korea through the increased co-firing biomass with coal.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.403-409
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• 2018

Inconel 713C which of a commercial Ni super alloy have the composition of 70 % Ni, 12 % Cr, 6 % Al and 4 % Mo. Mo is very expensive and have some economic value to recover in the alloy. In this study, liquid-liquid exraction(solvent extraction and stripping) has been performed to separate Mo from the synthetic leaching solution of spent Inconel 713C alloy and prepare to Mo powder by dying, evaporation and heat treatment. The experiments were conducted by using synthetic leaching solution which was prepared $NaMoO_4$ $2H_2O$ by dissolved in distilled water. Alamine336 and Cyanex272 dissolved in kerosene were used as extractants. The extraction percentage of Mo by Alamine336 is 99 % in the condition of the range of pH 1 to 4 and 1 % of concentration of Alamine336. The stripping solutions are used by HCl, $H_2SO_4$ and $HNO_3$ solutions and the concentrations were controlled by distilled water. The concentrations of HCl, $H_2SO_4$ and $HNO_3$ as stripping solutions are increased, the stripping percentages of Mo are increased and the stripping percentage of Mo by $HNO_3$ is higher than other stripping solutions. After liquid-liquid extraction and heat treatment, $MoO_3$ powder which of the purity of 97.5 % was prepared.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.5
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• pp.851-858
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• 2021

Due to the increase in renewable energy and distributed resources, not only traditional data but also various energy-related data are being generated in the new energy industry. In other words, there are various renewable energy facilities and power generation data, system operation data, metering and rate-related data, as well as weather and energy efficiency data necessary for new services and analysis. Energy big data processing technology can systematically analyze and diagnose data generated in the first half of the power production and consumption infrastructure, including distributed resources, systems, and AMI. Through this, it will be a technology that supports the creation of new businesses in convergence between the ICT industry and the energy industry. To this end, research on the data analysis system, such as itemized characteristic analysis of the collected data, correlation sampling, categorization of each feature, and element definition, is needed. In addition, research on data purification technology for data loss and abnormal state processing should be conducted. In addition, it is necessary to develop and structure NIFI, Spark, and HDFS systems so that energy data can be stored and managed in real time. In this study, the overall energy data processing technology and system for various power transactions as described above were proposed.