• New & Renewable Energy
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• v.9 no.1
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• pp.12-16
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• 2013

The nacelle anemometer mounted behind the blade roots of a wind turbine measures distorted wind speed comparable with free-stream wind because of the wake effects caused dependent upon the operation of the wind turbine and the rotation of its blades. The field campaign was carried out to measure free-stream wind speed at a height identical to the height of the nacelle anemometer by deploying a ground-based remote-sensing equipment, LIDAR. It is derived that a third-order polynomial equation for correcting wind speed measured by the nacelle anemometer to undistorted free-stream wind speed incident to a wind turbine. It is anticipated that the derived correction equation enables wind speed measured by the nacelle anemometer to be used as a precise input for a wind turbine performance test and for developing an active control logic.

• Environmental and Resource Economics Review
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• v.30 no.4
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• pp.607-625
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• 2021

The objective of this study is to estimate the relationship between CO₂ emissions and both nuclear power and renewable energy generation, and compare the cost efficiencies of nuclear power and renewable energy generation in reducing CO₂ emissions in Korea. The results show that nuclear power and renewable energy generation should be increased by 1.344% and 7.874% to reduce CO₂ emissions by 1%, respectively. Using the estimated coefficients and the levelized costs of electricity by source including the external costs, if the current amount of electricity generation is one megawatt-hour, the range of generation cost of nuclear power generation to reduce 1% CO₂ emissions is $0.72~$1.49 depending on the level of external costs. In the case of renewable energy generation, the generation cost to reduce 1% CO₂ emissions is $6.49. That is, to mitigate 1% of CO₂ emissions at the total electricity generation of 353 million MWh in 2020 in Korea, the total generation costs range for nuclear power is $254 million~$526 million for the nuclear power, and the cost for renewable energy is $2.289 billion for renewable energy. Hence, we can conclude that, in Korea, nuclear power generation is more cost-efficient than renewable energy generation in mitigating CO₂ emissions, even with the external costs of nuclear power generation.

• Korean Journal of Agricultural Science
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• v.38 no.1
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• pp.183-190
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• 2011

The paper is to analyze multi-attributes for expanding new renewable energy in agricultural sectors which have environmental, technical, economic, and social factors consisting of 15 attributes which have both positive and negative impacts. We applied the analytic hierarchy process (AHP) to data from opinion polls. As a result of the AHP survey, the overall results indicate that the respondents more weight on economical factor than environmental, technical, and social factors for expanding new renewable energy. At the lowest level, a comparison of individual 15 attributes within three factors shows that fixed cost highest in multi-attributes, followed by operating cost, technical superiority. To achieve the public acceptance about expanding new renewable energy in agricultural sectors, the policy-makers should take all relevant factors into account through the decision-making process by the public opinions.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.3
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• pp.85-92
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• 2004

Biomass is considered to be a major potential fuel and renewable resource for the future. In fact, there is high potential to produce significant amount of energy from biomass around the world. In spite of the potential, there are a few efforts in biomass utilization in this nation. In this study, elemental biomass data was obtained with respect to the amount and calorific values of agricultural residues. Rice straw and husks were not included in the evaluation due to their demand from alternative uses such as livestock feedings, bedding materials, and so forth. Dry basis high calorific values are about 4,500 kcal/kg for all the agricultural residues investigated, similar to literature data. Energy densities or unit area energy value, from pepper and sesame were significant and comparable to those of woody biomass. These elemental data for biomass resources will Provide the background of Planning and development of biomass energy Program, which is getting more feasible along with advances in energy conversion technologies such as micro gas turbines.

• Journal of the Korean Solar Energy Society
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• v.36 no.1
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• pp.11-18
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• 2016

The local wind systems in the Pohang region were categorized into wind sectors. Still, thorough knowledge of wind resource assessment, wind environment analysis, and atmospheric environmental impact assessment was required since the region has outstanding wind resources, it is located on the path of typhoon, and it has large-scale atmospheric pollution sources. To overcome the resolution limitation of meteorological dataset and problems of categorization criteria of the preceding studies, the high-resolution wind resource map of the Korea Institute of Energy Research was used as time-series meteorological data; the 2-step method of determining the clustering coefficient through hierarchical clustering analysis and subsequently categorizing the wind sectors through non-hierarchical K-means clustering analysis was adopted. The similarity of normalized time-series wind vector was proposed as the Euclidean distance. The meteor-statistical characteristics of the mean vector wind distribution and meteorological variables of each wind sector were compared. The comparison confirmed significant differences among wind sectors according to the terrain elevation, mean wind speed, Weibull shape parameter, etc.

• Environmental and Resource Economics Review
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• v.20 no.4
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• pp.797-826
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• 2011

This study analyzed whether a spatial difference exists in the willingness to pay(WTP) for renewable electricity, by applying the contingent valuation method(CVM). Considering renewable portfolio standards(RPS) as the hypothetical market, we asked WTP in the form of the monthly electricity bills for using renewable electricity; the respondents were people living in Seoul, Ulsan, JeollaNamdo, and Gangwondo. Our empirical results showed that the mean WTP of Gangwondo was the highest, and that of JeollaNamdo, the lowest. The hypothesis that the WTP of the entire sample would not differ from that of the individual regions was rejected. Hence, a spatial difference probably exists in the WTP for electricity from renewable energy. Further, we attributed the spatial differences in WTP to the experience of those staying near the renewable energy facility and the acceptability of the facility.

• New & Renewable Energy
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• v.10 no.2
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• pp.29-39
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• 2014

This study examines the future variability of surface wind speed and solar radiation based on climate change scenario over the Korean Peninsula. Climate change scenarios used in this study are RCP 4.5 and 8.5 with a 12.5 km horizontal resolution. Climate change scenario RCP 4.5 and 8.5 reproduce the general features of wind speed over the Korean Peninsula, such as strong wind speed during spring and winter and weak wind speed during summer. When compared with the values of wind speed and solar radiation of the future, they are expected to decrease current wind and solar resource map. Comparing the resource maps using RCP 4.5 and 8.5 scenarios, wind speed and solar radiation decrease with increasing greenhouse gas concentration. Meteorological resource maps of future wind and solar radiation should be improved with high resolution for the industrial application.

• Ocean Systems Engineering
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• v.13 no.3
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• pp.247-268
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• 2023

Tidal stream energy extraction remains a site-specific resource due to the "first generation" criteria requiring high-velocity tidal streams. Most studies on tidal energy and turbine blade design heavily focus on installation sites with higher velocity conditions that are non-existent in tropical countries such as the Philippines. To shorten this gap, this review paper tackles tidal turbine design considerations for low-energetic regions such as the tropics. In-depth discussions of operating principles, methods of analysis, and designs of tidal turbine blades are presented. Notable tidal stream projects around the world are also mentioned in the paper. Also, it provides a perspective on the potential of this renewable energy to produce electricity for various sites in the Philippines. Finally, the paper emphasizes the need for new tidal turbine blade designs to be viable in tropical regions, such as the Philippines.

• New & Renewable Energy
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• v.6 no.2
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• pp.5-11
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• 2010

This paper reviews three commercial softwares for wind climate data analysis in wind resource assessment; WAsP/Observed Wind Climate, WindRose and Windographer. Windographer is evaluated as the best software because of its variety of input data format, analysis functions, easiness of user interface, etc. For a quantitative understanding of uncertainty depending on software selection, a benchmark is carried out with the met-mast observation dataset at the Gimnyeong Wind Turbine Performance Test Site. It is found that Weibull parameter calculation and air density correction have a dependency on the software so that such uncertainty should be considered when an analysis software is selected. It is confirmed that annual energy production calculated by WAsP using a statistical table of frequency of occurrence may have some error compared to a time-series calculation method used by the other softwares.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.3
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• pp.205-210
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• 2008

In recent years, the crisis of energy is growing seriously and also the contamination of ecology has been reverberated as international problem. The social concern about energy crisis has been growing for the last several years and also the interest in new and renewable energy has been increased. The probability of wind power resource over Saemangeum is reviewed with the data of Gunsan weather station. Through this study, it is cleared that the Saemangeum area has fluent wind power source to design the wind farm in Korea. According to calculation results, it is possible to predict the wind velocity density around the Saemangeum area using the shape factor as a parameter.