• New & Renewable Energy
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• v.18 no.3
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• pp.43-59
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• 2022

The green premium is the most important feature of Korea's RE100 system. Green premium has three characteristics. The first, the cost of implementation is lower than that of other means of implementation. The second, it is linked with the RPS system to keep the means of implementing the green premium low. Third, the funds raised by the green premium are used to supply renewable energy to compensate for the additionality that the green premium does not have. When the entire industrial sector's electricity consumption is converted to renewable energy, the implementation cost of the green premium is estimated to be 3,377.4 billion won, and the REC purchase is estimated to incur the implementation cost of 6,576.4 billion won, which is 3.5 trillion more than the green premium. It was analyzed that an additional implementation cost of KRW 100 million would occur. In addition, in the case of solar PPA, it was analyzed that additional implementation costs of KRW 13,375.7 billion to KRW 16,162.3 billion were incurred. It was estimated that the renewable energy that could be supplied to the green premium would at least be sufficient for companies exporting to the US and EU. In addition, it was analyzed that when the fund created as a green premium is used for renewable energy supply, about 30.7% of the renewable energy supply through PPA can be supplied. However, as ESG is emphasized, green premium can be criticized by green washing because there is no additionality. There is also a limit to responding to the EU's CBAM. Therefore, companies can use the green premium depending on the situation, but it is more advantageous to use PPA, etc. The government needs to sufficiently maintain the supply of renewable energy using the fund to maintain the green premium.

• Journal of the Korean Solar Energy Society
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• v.39 no.3
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• pp.59-66
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• 2019

New and renewable energy forecasts are key technology to reduce the annual operating cost of new and renewable facilities, and accuracy of forecasts is paramount. In this study, we intend to build a model for the prediction of short-term solar power generation for 1 hour to 3 hours. To this end, this study applied two time series technique, ARIMA model without considering seasonality and SARIMA model with considering seasonality, comparing which technique has better predictive accuracy. Comparing predicted errors by MAE measures of solar power generation for 1 hour to 3 hours at four locations, the solar power forecast model using ARIMA was better in terms of predictive accuracy than the solar power forecast model using SARIMA. On the other hand, a comparison of predicted error by RMSE measures resulted in a solar power forecast model using SARIMA being better in terms of predictive accuracy than a solar power forecast model using ARIMA.

• New & Renewable Energy
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• v.17 no.4
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• pp.1-8
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• 2021

To determine the wind turbine class in the offshore of the Korean Peninsula, the reference wind speed for a 50-y return period at the hub height of a wind turbine was estimated using the reanalysis data sets. The most recent reanalysis data, ERA5, showed the highest correlation coefficient (R) of 0.82 with the wind speed measured by the Southwest offshore meteorological tower. However, most of the reanaysis data sets except CFSR underestimated the annual maximum wind speed. The gust factor of converting the 1 h-average into the 10 min-average wind speed was 1.03, which is the same as the WMO reference, using several meteorological towers and lidar measurements. Because the period, frequency, and path of typhoons invading the Korean Peninsula has been changing owing to the climate effect, significant differences occurred in the estimation of the extreme wind speed. Depending on the past data period and length, the extreme wind speed differed by more than 30% and the extreme wind speed decreased as the data period became longer. Finally, a reference wind speed map around the Korean Peninsula was drawn using the data of the last 10 years at the general hub-height of 100 m above the sea level.

• Journal of the Korean Solar Energy Society
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• v.40 no.4
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• pp.13-22
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• 2020

As the supply of photovoltaic (PV) increases worldwide, the cumulative installations in 2018 were 7.9 and 560 GW in Korea and the world, respectively. Typically, when the ground on commercial PV modules is installed, the area is limited; hence, new designs of PV modules are required to install additional PVs. Among the new design of PV modules, lightweight PV modules can be utilized in PV systems, such as buildings, farmlands, and floating PV. Concerning the investigation of lightweight PV modules, several studies on materials for replacing low-iron tempered glass, which comprises approximately 65% of the PV module weight, have been conducted. However, materials that are used as substitutes for glass should possess similar lightweight properties and reliability as glass. In this study, experimental tests were performed to evaluate the applicability of ethylene tetrafluoroethylene (ETFE) film with excellent resistance to water and aging as a front material of PV modules. The transmittance and ultraviolet properties of the ETFE film were determined and compared with those of glass. A 1-cell module and laboratory-scale 24-cell module were manufactured using the ETFE film and glass, and the electrical output was measured and analyzed. Furthermore, damp heat and thermal cycle tests were conducted to evaluate the reliability of the ETFE film module. Based on the experimental results, the electrical output and reliability of the ETFE film module were similar to those of the glass module, and the ETFE film could be used as the front material of PV modules.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.10
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• pp.4848-4863
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• 2016

The explosive wireless data service requirement accompanied with carbon dioxide emission and consumption of traditional energy has put pressure on both industria and academia. Wireless networks powered with the uneven and intermittent generated renewable energy have been widely researched and lead to a new research paradigm called green communication. In this paper, we comprehensively consider the total generated renewable energy, QoS requirement and channel quality, then propose a utility based renewable energy allocation policy. The utility here means the satisfaction degree of users with a certain amount allocated renewable energy. The energy allocation problem is formulated as a constraint optimization problem and a heuristic algorithm with low complexity is derived to solve the raised problem. Numerical results show that the renewable energy allocation policy is applicable not only to soft QoS, but also to hard QoS and best effort QoS. When the renewable energy is very scarce, only users with good channel quality can achieve allocated energy.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.2
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• pp.137-142
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• 2021

A Photovoltaic power streetlight is a system that uses solar energy to charge a secondary battery and then uses it for night lighting through a lamp, and can be configured as a standalone or grid-connected type by installing an LED streetlight at the load end. The energy generated through the solar cell module can be charged to the secondary battery through the charge/discharge control device, and then the LED street light can be turned on and off by comparing the power generation voltage and the charging voltage according to the monitoring of solar radiation, or by setting a specific time after sunset or sunrise. Based on these contents, this paper designed and manufactured a simulated solar power streetlight for education using new and renewable energy utilization and storage functions. Using these educational equipment, students can 1) understand the flow of energy change using renewable energy including sunlight as electric energy, 2) understand new and renewable energy, and cultivate basic design and manufacturing application power of related products, 3) The use of new and renewable energy through power conversion and strengthening of practical training and analysis through hardware production can be instilled.

• New & Renewable Energy
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• v.3 no.3
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• pp.20-27
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• 2007

태양광 분야에서 일본은 기술 및 보급에 성공한 대표적인 사례로서 거론된다. 태양광의 에너지자원화를 목표로 30여 년간 지속적으로 국가차원의 기술개발 및 보급을 정책 사업화하여 진행시켰고 성공적인 선행 단계를 밟아 왔다. 현재까지의 성공을 기반으로 [태양광 비전 2030]을 수립하여 실현가능한 장기 목표를 구체화하는 단계에 있다. 이에 일본 태양광 산업 및 기술개발 방향에 대한 분석을 통해 오늘 우리에게 주는 시사점을 도출하여 차세대 성장 동력 산업이 될 국내 태양광분야의 발전을 위한 지표로 삼고자 한다.

• New & Renewable Energy
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• v.7 no.3
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• pp.92-100
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• 2011

With the increased demand of clean energy and global warming measures, the renewable energy development has been increased recently. The TCP (Tidal Current Power) is one of the ocean renewable energy sources. Having the high tidal energy source in Korea, there are many potential TCP sites with strong current speed. The rotor, which initially converts the energy, is a very important component because it affects the efficiency of the entire system. The rotor performance is determined by various design parameters including number of blades, shape, sectional size, diameters and etc. However, the interactions between devices also contribute significantly to the energy production. The rotor performance considering the interaction needs to be investigated to predict the exact power in the farm. This paper introduces the optimum design of TCP turbine and the performance of devices considering the interference between rotors.

• Journal of the Korean Solar Energy Society
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• v.39 no.2
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• pp.71-80
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• 2019

Daily ahead forecast is necessary for the electricity balance between load and supply due to the variability renewable energy. Numerical weather prediction is usually employed to produce the solar irradiance as well as electric power forecast for more than 12 hours forecast horizon. UM-LDAPS model is the numerical weather prediction operated by Korea Meteorological Administration and it generates the 36 hours forecast of hourly total irradiance 4 times a day. This study attempts to evaluate the model performance against the in situ measurements at 37 ground stations from January to May, 2013. Relative mean bias error, mean absolute error and root mean square error of hourly total irradiance are averaged over all ground stations as being 8.2%, 21.2% and 29.6%, respectively. The behavior of mean bias error appears to be different; positively largest in Chupoongnyeong station but negatively largest in Daegu station. The distinct contrast might be attributed to the limitation of microphysics parameterization for thick and thin clouds in the model.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.658-661
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• 2007

It was investigated on this paper that the status of biomass energy utilization in the registered CDM projects. The ratio of the case including the energy recovery among the registered biomass CDM projects is just about 57%. Direct thermal conversion technology is the most commonly applied for biomass energy recovery projects. Through the comparative study with world renewable energy outlook, the contribution of CDM to biomass energy supply in the world is not considerable yet.