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Photovoltaic (PV) power fluctuations caused by weather changes can lead to short-term mismatches in power demand and supply. Therefore, to operate the power grid efficiently and reliably, short-term PV power forecasts are required against these fluctuations. In this paper, we propose a deep RNN-based PV power short-term forecast. To reflect the impact of weather changes, the proposed model utilizes the on-site weather IoT dataset and power data, collected in real-time. We investigated various parameters of the proposed deep RNN-based forecast model and the combination of weather parameters to find an accurate prediction model. Experimental results showed that accuracies of 5 and 15 min ahead PV power generation forecast, using 3 RNN layers with 12 time-step, were 98.0% and 96.6% based on the normalized RMSE, respectively. Their R2-scores were 0.988 and 0.949. In experiments for 1 and 3 h ahead of PV power generation forecasts, their accuracies were 94.8% and 92.9%, respectively. Also, their R2-scores were 0.963 and 0.927. These experimental results showed that the proposed deep RNN-based short-term forecast algorithm achieved higher prediction accuracy.
Hyung Keun Ahn; Neungsoo Park. Deep RNN-Based Photovoltaic Power Short-Term Forecast Using Power IoT Sensors. Energies 2021, 14, 436 .
AMA StyleHyung Keun Ahn, Neungsoo Park. Deep RNN-Based Photovoltaic Power Short-Term Forecast Using Power IoT Sensors. Energies. 2021; 14 (2):436.
Chicago/Turabian StyleHyung Keun Ahn; Neungsoo Park. 2021. "Deep RNN-Based Photovoltaic Power Short-Term Forecast Using Power IoT Sensors." Energies 14, no. 2: 436.
In this paper, a design technique for constructing a renewable-energy-based power system based on a customer’s power load is proposed. The proposed design technique adopts a second renewable energy power source in charge of the base load and is an improved method of the referenced studies with one type of renewable energy power source. In this proposed method, fuel cells are adopted as the base power source, and PV (photovoltaic) power generation and an ESS (energy storage system) are adopted as the power generation sources that supply the middle-load and peak-load power. When the fuel cell is applied as a base power source through the method designed in this study, a cost reduction of approximately 30.03% is expected, compared to a system that does not use a base power source. In addition, the criteria for securing a system’s power supply stability and the economics when fuel cells are adopted are analyzed in terms of the system’s installation cost.
Sang Hun Lee; Wonbin Lee; Jin Hee Hyun; Byeong Gwan Bhang; Jinho Choi; Hyung Keun Ahn. Capacity Design and Cost Analysis of Converged Renewable Energy Resources by Considering Base Load Conditions in Residential and Industrial Areas. Applied Sciences 2020, 10, 7822 .
AMA StyleSang Hun Lee, Wonbin Lee, Jin Hee Hyun, Byeong Gwan Bhang, Jinho Choi, Hyung Keun Ahn. Capacity Design and Cost Analysis of Converged Renewable Energy Resources by Considering Base Load Conditions in Residential and Industrial Areas. Applied Sciences. 2020; 10 (21):7822.
Chicago/Turabian StyleSang Hun Lee; Wonbin Lee; Jin Hee Hyun; Byeong Gwan Bhang; Jinho Choi; Hyung Keun Ahn. 2020. "Capacity Design and Cost Analysis of Converged Renewable Energy Resources by Considering Base Load Conditions in Residential and Industrial Areas." Applied Sciences 10, no. 21: 7822.
Fault detection and repair of the components of photovoltaic (PV) systems are essential to avoid economic losses and facility accidents, thereby ensuring reliable and safe systems. This article presents a method to detect faults in a PV system based on power ratio (PR), voltage ratio (VR), and current ratio (IR). The lower control limit (LCL) and upper control limit (UCL) of each ratio were defined using the data of a test site system under normal operating conditions. If PR exceeded the set range, the algorithm considered a fault. Subsequently, PR and IR were examined via the algorithm to diagnose faults in the system as series, parallel, or total faults. The results showed that PR exceeded the designated range between LCL (0.93) and UCL (1.02) by dropping to 0.91–0.68, 0.88–0.62, and 0.66–0.33 for series, total, and parallel faults, respectively. Moreover, VR exceeded the LCL (0.99) and UCL (1.01) by 0.95–0.69 and 0.91–0.62 for series and total faults, respectively, but not under parallel faults condition. IR did not change in series and total faults but exceeded the range of LCL (0.93) and UCL (1.05) by dropping to 0.66–0.33. Thus, faults in PV systems can be detected and diagnosed by analyzing quantitative output values.
Gyu Gwang Kim; Wonbin Lee; Byeong Gwan Bhang; Jin Ho Choi; Hyung-Keun Ahn. Fault Detection for Photovoltaic Systems Using Multivariate Analysis With Electrical and Environmental Variables. IEEE Journal of Photovoltaics 2020, 11, 202 -212.
AMA StyleGyu Gwang Kim, Wonbin Lee, Byeong Gwan Bhang, Jin Ho Choi, Hyung-Keun Ahn. Fault Detection for Photovoltaic Systems Using Multivariate Analysis With Electrical and Environmental Variables. IEEE Journal of Photovoltaics. 2020; 11 (1):202-212.
Chicago/Turabian StyleGyu Gwang Kim; Wonbin Lee; Byeong Gwan Bhang; Jin Ho Choi; Hyung-Keun Ahn. 2020. "Fault Detection for Photovoltaic Systems Using Multivariate Analysis With Electrical and Environmental Variables." IEEE Journal of Photovoltaics 11, no. 1: 202-212.
In this study, the temperatures of high-density PV modules (HDMs) were predicted by considering the effect of relative humidity. First, factors that could affect the module temperature were analyzed. It was found that humidity affects the Prandtl number, the thermal conductivity between the module and air, and the viscosity of air. Experiments were performed to confirm that the PV module temperature increases as the relative humidity increases. The differential equation of the energy balance model was solved by considering the relative humidity to verify the accuracy of module temperature prediction during indoor and outdoor experiments. A MAPE of (0.8843[%]) and an RMSE of (0.45) were obtained for the indoor experiment. With regard to the outdoor experiment, both MAPEnatural and MAPEtotal were measured separately. The most accurate prediction was obtained for the month of April, with MAPEnatural and MAPEtotal values of (0.216[%]) and (0.1197[%]), respectively. The most inaccurate prediction considering MAPEnatural, which had a value of (1.698[%]), was obtained for December. Furthermore, the most inaccurate prediction considering MAPEtotal, which had a value of (0.485[%]), was obtained for August. The most accurate prediction considering RMSEnatural (2.605) was obtained for June, and that considering RMSE total (2.223) was obtained for December. The most inaccurate prediction considering RMSEnatural (5.785) was obtained for November, and that considering RMSEtotal (3.093) was obtained for April. These predictions were accurate only when natural and forced convection were considered. In summary, relative humidity affects the atmosphere around the PV module and the module temperature, thereby affecting the power performance of the PV module.
Jin Ho Choi; Jinhee Hyun; Wonbin Lee; Byung-Gwan Bhang; Yong Ki Min; Hyung-Keun Ahn. Power performance of high density photovoltaic module using energy balance model under high humidity environment. Solar Energy 2020, 219, 50 -57.
AMA StyleJin Ho Choi, Jinhee Hyun, Wonbin Lee, Byung-Gwan Bhang, Yong Ki Min, Hyung-Keun Ahn. Power performance of high density photovoltaic module using energy balance model under high humidity environment. Solar Energy. 2020; 219 ():50-57.
Chicago/Turabian StyleJin Ho Choi; Jinhee Hyun; Wonbin Lee; Byung-Gwan Bhang; Yong Ki Min; Hyung-Keun Ahn. 2020. "Power performance of high density photovoltaic module using energy balance model under high humidity environment." Solar Energy 219, no. : 50-57.
Byeong Gwan Bhang; Sung Cheol Woo; Wonbin Lee; Jin Ho Choi; Seungwook Shin; Chulsung Lee; Milan Park; Changsub Won; Hyungkeun Ahn. Transmission Loss from Voltage Drop in a DC Cable for a Floating Photovoltaic System in a Reservoir. New & Renewable Energy 2020, 16, 48 -57.
AMA StyleByeong Gwan Bhang, Sung Cheol Woo, Wonbin Lee, Jin Ho Choi, Seungwook Shin, Chulsung Lee, Milan Park, Changsub Won, Hyungkeun Ahn. Transmission Loss from Voltage Drop in a DC Cable for a Floating Photovoltaic System in a Reservoir. New & Renewable Energy. 2020; 16 (1):48-57.
Chicago/Turabian StyleByeong Gwan Bhang; Sung Cheol Woo; Wonbin Lee; Jin Ho Choi; Seungwook Shin; Chulsung Lee; Milan Park; Changsub Won; Hyungkeun Ahn. 2020. "Transmission Loss from Voltage Drop in a DC Cable for a Floating Photovoltaic System in a Reservoir." New & Renewable Energy 16, no. 1: 48-57.
In this study, a general building of medium size with an Energy Storage Systems (ESS)-connected Photovoltaic (PV) system (energy storage system that is connected to a photovoltaic system) was chosen to develop a tool for a better economic evaluation of its installation and use. The newly obtained results, from the revised economic evaluation algorithm that was proposed in this study, showed the effective return of investment period (ROI) would be 8.62 to 12.77 years. The ratio of maximum power demand to contract demand and the falling cost of PVs and ESS was the factors that could affect the ROI. While using the cost scenario of PVs and ESS from 2019 to 2024, as estimated by the experts, the ROI was significantly improved. The ROI was estimated to be between 4.26 to 8.56 years by the year 2024 when the cost scenario was considered. However, this result is obtained by controlling the ratio of maximum power demand to contract demand. Continued favorable government policies concerning renewable energy would be crucial in expanding the supply and investment in renewable energy resources, until the required ROI is attained.
Sung-Soo Kim; Wonbin Lee; Byeong Gwan Bhang; Jin Ho Choi; Sang Hun Lee; Sung Cheol Woo; Woo Jun Nam; Hyung Keun Ahn; Lee. Return of Interest Planning for Photovoltaics Connected with Energy Storage System by Considering Maximum Power Demand. Applied Sciences 2020, 10, 786 .
AMA StyleSung-Soo Kim, Wonbin Lee, Byeong Gwan Bhang, Jin Ho Choi, Sang Hun Lee, Sung Cheol Woo, Woo Jun Nam, Hyung Keun Ahn, Lee. Return of Interest Planning for Photovoltaics Connected with Energy Storage System by Considering Maximum Power Demand. Applied Sciences. 2020; 10 (3):786.
Chicago/Turabian StyleSung-Soo Kim; Wonbin Lee; Byeong Gwan Bhang; Jin Ho Choi; Sang Hun Lee; Sung Cheol Woo; Woo Jun Nam; Hyung Keun Ahn; Lee. 2020. "Return of Interest Planning for Photovoltaics Connected with Energy Storage System by Considering Maximum Power Demand." Applied Sciences 10, no. 3: 786.
This work is a case study of 905 households, to present methods for optimizing the capacity of photovoltaic sytems (PVs)/energy storage systems (ESSs) for household to reach a desired energy self-sufficiency (70% to 90%). In order to calculate the capacity of PV and ESSs that would enhance the energy self-sufficiency of families in rural areas, the solar radiance data of the target area for the last five years and the average monthly power usage in the previous year were collected. Then, households with an average energy consumption of 250 kWh per month were chosen for this research. According to the simulation done using Solar Pro, the optimized capacities of PVs and ESSs are 2.67 kW and 7.15 kW, respectively, in order to achieve 90% energy self-sufficiency. We visualized the change in the optimum capacity of PVs and ESSs for the desired energy self-sufficiency. This study would be the base work for forming a grid-distributed energy network system by expanding the system to a national scale.
Choon Young Cho; Wonbin Lee; Byeong Gwan Bhang; Jinho Choi; Sang Hun Lee; Sung Cheol Woo; Hyung Keun Ahn. Convergence Analysis of Capacities for Photovoltaics and Energy Storage System Considering Energy Self-Sufficiency Rates and Load Patterns of Rural Areas. Applied Sciences 2019, 9, 5323 .
AMA StyleChoon Young Cho, Wonbin Lee, Byeong Gwan Bhang, Jinho Choi, Sang Hun Lee, Sung Cheol Woo, Hyung Keun Ahn. Convergence Analysis of Capacities for Photovoltaics and Energy Storage System Considering Energy Self-Sufficiency Rates and Load Patterns of Rural Areas. Applied Sciences. 2019; 9 (24):5323.
Chicago/Turabian StyleChoon Young Cho; Wonbin Lee; Byeong Gwan Bhang; Jinho Choi; Sang Hun Lee; Sung Cheol Woo; Hyung Keun Ahn. 2019. "Convergence Analysis of Capacities for Photovoltaics and Energy Storage System Considering Energy Self-Sufficiency Rates and Load Patterns of Rural Areas." Applied Sciences 9, no. 24: 5323.
Unlike conventional photovoltaic (PV) modules that generate power by absorbing light through the front side only, a bifacial PV module can generate power by absorbing light through the rear as well as the front, which would lead to an enhancement of power generation. Particularly, bifacial PV modules would have the advantage of lower power loss in shaded environments than monofacial PV modules, thanks to the light absorbed through the rear side. To predict the power of a bifacial PV module in a shaded environment, modeling is suggested by considering the shaded areas, the operational status of the bypass diodes, and the temperature of the bifacial PV module. To verify the power prediction of a bifacial PV module with a shaded area, modeled and measured powers are compared, showing error rates of 7.28%. From the results of the power loss experiments for bifacial and monofacial PV modules in shaded environments, it is confirmed that the bifacial PV module shows a relatively low power loss rate when compared with the monofacial PV module, with a power loss rate being 87.26% of the rate for the monofacial PV module.
Byeong Gwan Bhang; Wonbin Lee; Gyu Gwang Kim; Jin Ho Choi; So Young Park; Hyung-Keun Ahn. Power Performance of Bifacial c-Si PV Modules With Different Shading Ratios. IEEE Journal of Photovoltaics 2019, 9, 1413 -1420.
AMA StyleByeong Gwan Bhang, Wonbin Lee, Gyu Gwang Kim, Jin Ho Choi, So Young Park, Hyung-Keun Ahn. Power Performance of Bifacial c-Si PV Modules With Different Shading Ratios. IEEE Journal of Photovoltaics. 2019; 9 (5):1413-1420.
Chicago/Turabian StyleByeong Gwan Bhang; Wonbin Lee; Gyu Gwang Kim; Jin Ho Choi; So Young Park; Hyung-Keun Ahn. 2019. "Power Performance of Bifacial c-Si PV Modules With Different Shading Ratios." IEEE Journal of Photovoltaics 9, no. 5: 1413-1420.
The silicon wafers for solar cells on which the paste is deposited experience a bowing phenomenon. The thickness of commonly used c-Si wafers is 180 μm or more. When fabricating c-Si solar cells with this wafer thickness, the bowing value is 3 mm or less and the problem does not occur. However, for the thin c-Si solar cells which are being studied recently, the output reduction due to failure during manufacture and cracking are attributed to bowing. In generally, it is known that the bowing phenomenon arises mainly from the paste applied to the back side electrode of c-Si solar cells and the effects of SiNx (silicon nitride) and the paste on the front side are not considered significant. The bowing phenomenon is caused by a difference in the coefficient of expansion between heterogeneous materials, there is the effect of bowing on the front electrode and ARC. In this paper, a partially processed c-Si solar cell was fabricated and a bowing phenomenon variation according to the wafer thicknesses was confirmed. As a result of the experiment, the measured bow value after the firing process suggests that the paste on the front-side indicates a direction different from that of the back-side paste. The bow value increases when Al paste is deposited on SiNx. The fabricated c-Si solar cell was analyzed on basis of the correlation between the bowing phenomenon of the materials and the c-Si wafer using Stoney’s equation, which is capable of analyzing the relationship between bowing and stress. As a result, the bowing phenomenon of the c-Si solar cell estimated through the experiment that the back side electrode is the important element, but also the front electrode and ARC influence the bowing phenomenon when fabricating c-Si solar cells using thin c-Si wafers.
Jong Rok Lim; Sihan Kim; Hyung-Keun Ahn; Hee-Eun Song; Gi Hwan Kang. Analysis of the Bowing Phenomenon for Thin c-Si Solar Cells using Partially Processed c-Si Solar Cells. Energies 2019, 12, 1593 .
AMA StyleJong Rok Lim, Sihan Kim, Hyung-Keun Ahn, Hee-Eun Song, Gi Hwan Kang. Analysis of the Bowing Phenomenon for Thin c-Si Solar Cells using Partially Processed c-Si Solar Cells. Energies. 2019; 12 (9):1593.
Chicago/Turabian StyleJong Rok Lim; Sihan Kim; Hyung-Keun Ahn; Hee-Eun Song; Gi Hwan Kang. 2019. "Analysis of the Bowing Phenomenon for Thin c-Si Solar Cells using Partially Processed c-Si Solar Cells." Energies 12, no. 9: 1593.
With increasing installations of photovoltaic (PV) systems, interest in power forecasting has also increased. Inaccurate forecasts would result in substantial economic losses and system reliability issues. The correlation between weather variables and PV power is critical to ensure the efficient use of energy in PV systems. A key step toward accurate power forecasting is estimating the output from a PV system based on known environmental input data. In this research, all available weather data are used to predict the PV power. Meteorological and power data are then analyzed using a statistical approach to identify the order of significance of the input variables. Then, a predictive model is suggested as a function of irradiance, ambient temperature, wind speed, and relative humidity. The model produces a root mean square error of 4.957% and a mean absolute percentage error of 5.468% during the measurement period and over the entire range of irradiation.
GyuGwang Kim; Jin Ho Choi; So Young Park; Byeong Gwan Bhang; Woo Jun Nam; Hae Lim Cha; Neungsoo Park; Hyung-Keun Ahn. Prediction Model for PV Performance With Correlation Analysis of Environmental Variables. IEEE Journal of Photovoltaics 2019, 9, 832 -841.
AMA StyleGyuGwang Kim, Jin Ho Choi, So Young Park, Byeong Gwan Bhang, Woo Jun Nam, Hae Lim Cha, Neungsoo Park, Hyung-Keun Ahn. Prediction Model for PV Performance With Correlation Analysis of Environmental Variables. IEEE Journal of Photovoltaics. 2019; 9 (3):832-841.
Chicago/Turabian StyleGyuGwang Kim; Jin Ho Choi; So Young Park; Byeong Gwan Bhang; Woo Jun Nam; Hae Lim Cha; Neungsoo Park; Hyung-Keun Ahn. 2019. "Prediction Model for PV Performance With Correlation Analysis of Environmental Variables." IEEE Journal of Photovoltaics 9, no. 3: 832-841.
A bifacial solar module has a structure that allows the rear electrode to be added to the existing silicon photovoltaic module structure. Thus, it can capture energy from both the front and rear sides of the module. In this paper, modeling is suggested to estimate the amount of energy generated from the rear of the bifacial photovoltaic module. After calculating the amount of irradiance from the rear side, the estimated power generation is compared with the real power output from the rear side of the module. The experiments were performed using four different environments with different albedos. The theoretical prediction of the model shows a maximum of 5% and average of 1.86% error in the measurement data. Based on the nature of the bifacial solar module, which receives additional irradiance from the rear side, this study compared the output amounts with respect to different rear environments. Recently, installation of floating Photovoltaic has been increasing. As the reflection of irradiation from the water surface occurs, the positive influence of the installation with the bifacial photovoltaic can be expected. We are confident that this research will contribute to zero energy construction by designing systems based on bifacial PV module with high performance ratio when applying solar power in a microgrid environment, which is the future energy.
Hae Lim Cha; Byeong Gwan Bhang; So Young Park; Jin Ho Choi; Hyung Keun Ahn. Power Prediction of Bifacial Si PV Module with Different Reflection Conditions on Rooftop. Applied Sciences 2018, 8, 1752 .
AMA StyleHae Lim Cha, Byeong Gwan Bhang, So Young Park, Jin Ho Choi, Hyung Keun Ahn. Power Prediction of Bifacial Si PV Module with Different Reflection Conditions on Rooftop. Applied Sciences. 2018; 8 (10):1752.
Chicago/Turabian StyleHae Lim Cha; Byeong Gwan Bhang; So Young Park; Jin Ho Choi; Hyung Keun Ahn. 2018. "Power Prediction of Bifacial Si PV Module with Different Reflection Conditions on Rooftop." Applied Sciences 8, no. 10: 1752.
A distributed power generation system uses an intermittent power source that provides low power. Furthermore, it cannot be centrally controlled from the perspective of the system operator. The photovoltaic (PV) power generation system is installed with an energy storage system (ESS) to increase the power source quality compared to that possible with PV-only power generation. In this paper, an estimation algorithm is proposed for improving battery capacity to construct a suitable and economical system. In addition, an optimal algorithm is proposed that considers different factors. For example, the cost of constructing the battery and the amount of electric power sales reflecting the renewable energy certificate weighting factor of 5.0 are based on the cost of the battery construction, depth of battery discharge, charge/discharge cycle of the battery, cost of the energy conversion device, operation maintenance cost, and charge cycle of the battery. The optimized battery capacity is calculated by considering the correlation between PV power and meteorological parameters, construction cost, and the benefit of the amount of electricity sold, with an error rate of 5.75%.
Hyun Gu Lee; Gyu Gwang Kim; Byeong Gwan Bhang; David Kwangsoon Kim; Neungsoo Park; Hyung Keun Ahn. Design Algorithm for Optimum Capacity of ESS Connected With PVs Under the RPS Program. IEEE Access 2018, 6, 45899 -45906.
AMA StyleHyun Gu Lee, Gyu Gwang Kim, Byeong Gwan Bhang, David Kwangsoon Kim, Neungsoo Park, Hyung Keun Ahn. Design Algorithm for Optimum Capacity of ESS Connected With PVs Under the RPS Program. IEEE Access. 2018; 6 ():45899-45906.
Chicago/Turabian StyleHyun Gu Lee; Gyu Gwang Kim; Byeong Gwan Bhang; David Kwangsoon Kim; Neungsoo Park; Hyung Keun Ahn. 2018. "Design Algorithm for Optimum Capacity of ESS Connected With PVs Under the RPS Program." IEEE Access 6, no. : 45899-45906.
This paper proposes a method for estimating the load pattern for optimal planning of stand-alone renewable microgrids and verifies when the basic data for microgrid design are limited. To estimate a proper load pattern for optimal microgrid design when the data obtained in advance are insufficient, the least squares method is used to compare the similarity of annual power consumption between the subject area and eight islands in Korea whose actual load patterns were previously obtained. Similarity is compared in terms of annual (every month), seasonal, bi-monthly, and monthly averages. To verify the validity of the proposed estimation method, the applied proposed estimation method is used for two islands that have already installed a microgrid consisting of photovoltaic, wind power, energy storage systems, and diesel generators. In comparing the actual data from the two islands, the costs of electricity in terms of microgrid operations show improvements of 37.2% and 29.8%, respectively.
Chang Koo Lee; Byeong Gwan Bhang; David Kwangsoon Kim; Sang Hun Lee; Hae Lim Cha; Hyung Keun Ahn. Estimation of Load Pattern for Optimal Planning of Stand-Alone Microgrid Networks. Energies 2018, 11, 2012 .
AMA StyleChang Koo Lee, Byeong Gwan Bhang, David Kwangsoon Kim, Sang Hun Lee, Hae Lim Cha, Hyung Keun Ahn. Estimation of Load Pattern for Optimal Planning of Stand-Alone Microgrid Networks. Energies. 2018; 11 (8):2012.
Chicago/Turabian StyleChang Koo Lee; Byeong Gwan Bhang; David Kwangsoon Kim; Sang Hun Lee; Hae Lim Cha; Hyung Keun Ahn. 2018. "Estimation of Load Pattern for Optimal Planning of Stand-Alone Microgrid Networks." Energies 11, no. 8: 2012.
An optimal design method is proposed in this paper to improve the safety and price competitiveness of floating photovoltaic (PV) systems. From the standards for grounding by the International Electrotechnical Commission (IEC) 60364, the Electrical Equipment Technology Standards (EETS) are set up for the grounding resistance to be less than or equal to 10 Ω for high voltage (above 750 V DC) and extra high voltage (above 7000 V) systems. In order to satisfy this criterion, a parallel connection of grounding electrodes is essential in the system. Furthermore, inter-electrode interference should be considered to reflect the resistance increase due to the potential increase between electrodes. Therefore, in this study, the parallel grounding resistance according to the distance and number of electrodes, as well as the arrangement method were theoretically predicted and compared with the measured values. For the first time, the design of grounding electrodes has been applied to real floating PV systems and is expected to satisfy EETS.
Byeong Gwan Bhang; Gyu Gwang Kim; Hae Lim Cha; David Kwangsoon Kim; Jin Ho Choi; So Young Park; Hyung Keun Ahn. Design Methods of Underwater Grounding Electrode Array by Considering Inter-Electrode Interference for Floating PVs. Energies 2018, 11, 982 .
AMA StyleByeong Gwan Bhang, Gyu Gwang Kim, Hae Lim Cha, David Kwangsoon Kim, Jin Ho Choi, So Young Park, Hyung Keun Ahn. Design Methods of Underwater Grounding Electrode Array by Considering Inter-Electrode Interference for Floating PVs. Energies. 2018; 11 (4):982.
Chicago/Turabian StyleByeong Gwan Bhang; Gyu Gwang Kim; Hae Lim Cha; David Kwangsoon Kim; Jin Ho Choi; So Young Park; Hyung Keun Ahn. 2018. "Design Methods of Underwater Grounding Electrode Array by Considering Inter-Electrode Interference for Floating PVs." Energies 11, no. 4: 982.
Rapid reduction in the price of photovoltaic (solar PV) cells and modules has resulted in a rapid increase in solar system deployments to an annual expected capacity of 200 GW by 2020. Achieving high PV cell and module efficiency is necessary for many solar manufacturers to break even. In addition, new innovative installation methods are emerging to complement the drive to lower $/W PV system price. The floating PV (FPV) solar market space has emerged as a method for utilizing the cool ambient environment of the FPV system near the water surface based on successful FPV module (FPVM) reliability studies that showed degradation rates below 0.5% p.a. with new encapsulation material. PV module temperature analysis is another critical area, governing the efficiency performance of solar cells and module. In this paper, data collected over five-minute intervals from a PV system over a year is analyzed. We use MATLAB to derived equation coefficients of predictable environmental variables to derive FPVM’s first module temperature operation models. When comparing the theoretical prediction to real field PV module operation temperature, the corresponding model errors range between 2% and 4% depending on number of equation coefficients incorporated. This study is useful in validation results of other studies that show FPV systems producing 10% more energy than other land based systems.
Waithiru Charles Lawrence Kamuyu; Jong Rok Lim; Chang Sub Won; Hyung Keun Ahn. Prediction Model of Photovoltaic Module Temperature for Power Performance of Floating PVs. Energies 2018, 11, 447 .
AMA StyleWaithiru Charles Lawrence Kamuyu, Jong Rok Lim, Chang Sub Won, Hyung Keun Ahn. Prediction Model of Photovoltaic Module Temperature for Power Performance of Floating PVs. Energies. 2018; 11 (2):447.
Chicago/Turabian StyleWaithiru Charles Lawrence Kamuyu; Jong Rok Lim; Chang Sub Won; Hyung Keun Ahn. 2018. "Prediction Model of Photovoltaic Module Temperature for Power Performance of Floating PVs." Energies 11, no. 2: 447.
Rapid reduction in the $/Wp prices of photovoltaic (solar PV) energy has been proceeded recently, resulting in near exponential deployments with an annual capacity of 200 GW expected by 2020. Achieving high efficiency is necessary for many solar manufacturers to break even. In addition, new innovative installation methods are emerging to complement the improvement of system performance. The floating PV (FPV) solar market space has emerged over the past decade as a method for utilizing the cool ambient environment of the FPV system near the water surface to boost the power output performance of the PV module and ultimately the yield of the PV system. PV module temperature, which is the most critical factor affecting efficiency, ultimately governs the effective performance of solar cells, module, and all semiconductor materials in general. We propose the first ever electrical efficiency equations ( η c,FP V 1 and η c,FP V 2 ) for an FPV module installed on water based on two new predictions of FPV temperature operation models (Tm1 and Tm2), whose coefficients are derived from FPV site data with MATLAB. The theoretical prediction of module temperature shows respective errors of 2% and 4% when compared to the FPVM measured data.
Waithiru Charles Lawrence K.; Jong Rok Lim; Chang Sub Won; Hyung Keun Ahn. Prediction Model of Photovoltaic Module Temperature for Power Performance of Floating PVs. 2017, 1 .
AMA StyleWaithiru Charles Lawrence K., Jong Rok Lim, Chang Sub Won, Hyung Keun Ahn. Prediction Model of Photovoltaic Module Temperature for Power Performance of Floating PVs. . 2017; ():1.
Chicago/Turabian StyleWaithiru Charles Lawrence K.; Jong Rok Lim; Chang Sub Won; Hyung Keun Ahn. 2017. "Prediction Model of Photovoltaic Module Temperature for Power Performance of Floating PVs." , no. : 1.
A methodology was developed to analyze the uniformity properties of amorphous silicon (a-Si) based triple-junction thin-film solar module for power stations or for building-integrated photovoltaic using circuit model parameters. First, a-Si-based triple-junction thin-film solar module with a size of 5G was fabricated via the mass production method. The module was divided into small modules with ten solar cells. A total of nine samples were selected and the dark I–V characteristics for each sample were measured. A circuit model for a triple-junction solar module was proposed. One sample that could represent the triple-junction properties was selected and the circuit parameters were extracted. The circuit model with the extracted parameters was simulated using H-spice and showed good agreement between experimental and simulation results. Ideality factors and reverse saturation currents from the selected samples were extracted from the dark IV curve and resistance parameters by using the numerical method with the circuit model. The distribution of each parameter for the samples and the uniformity of the large-size module were analyzed.
Yongki Min; Jong- Rok Lim; Jae-Woo Ko; Hyung-Keun Ahn. Analysis Method for the Uniformity of a-Si-Based Multijunction Thin-Film Solar Module Using Ideality Factors. IEEE Journal of Photovoltaics 2017, 7, 1488 -1495.
AMA StyleYongki Min, Jong- Rok Lim, Jae-Woo Ko, Hyung-Keun Ahn. Analysis Method for the Uniformity of a-Si-Based Multijunction Thin-Film Solar Module Using Ideality Factors. IEEE Journal of Photovoltaics. 2017; 7 (6):1488-1495.
Chicago/Turabian StyleYongki Min; Jong- Rok Lim; Jae-Woo Ko; Hyung-Keun Ahn. 2017. "Analysis Method for the Uniformity of a-Si-Based Multijunction Thin-Film Solar Module Using Ideality Factors." IEEE Journal of Photovoltaics 7, no. 6: 1488-1495.
Underwater grounding methods could be applied in deep water for grounding a floating PV (photovoltaic) system. However, the depth at which the electrodes should be located is a controversial subject. In this study, grounding resistance was measured for the first time by analyzing the water temperature at different water depths in an area where a floating PV system is installed. The theoretical calculation of the grounding resistance has a maximum error range of 8% compared to the experimentally measured data. In order to meet the electrical safety standards of a floating PV system, a number of electrodes were connected in parallel. In addition, the distance between electrodes and number of electrodes were considered in the test to obtain a formula for the grounding resistance. In addition, the coefficient of corrosion was obtained from an electrode installed underwater a year ago, and it was added to the formula. Through this analysis, it is possible to predict the grounding resistance prior to installing the floating PV system. Furthermore, the electrical safety of the floating PV system could be achieved by considering the seasonal changes in water temperature.
Jae Woo Ko; Hae Lim Cha; David Kwang-Soon Kim; Jong Rok Lim; Gyu Gwang Kim; Byeong Gwan Bhang; Chang Sub Won; Han Sang Jung; Dong Hyung Kang; Hyung Keun Ahn. Safety Analysis of Grounding Resistance with Depth of Water for Floating PVs. Energies 2017, 10, 1304 .
AMA StyleJae Woo Ko, Hae Lim Cha, David Kwang-Soon Kim, Jong Rok Lim, Gyu Gwang Kim, Byeong Gwan Bhang, Chang Sub Won, Han Sang Jung, Dong Hyung Kang, Hyung Keun Ahn. Safety Analysis of Grounding Resistance with Depth of Water for Floating PVs. Energies. 2017; 10 (9):1304.
Chicago/Turabian StyleJae Woo Ko; Hae Lim Cha; David Kwang-Soon Kim; Jong Rok Lim; Gyu Gwang Kim; Byeong Gwan Bhang; Chang Sub Won; Han Sang Jung; Dong Hyung Kang; Hyung Keun Ahn. 2017. "Safety Analysis of Grounding Resistance with Depth of Water for Floating PVs." Energies 10, no. 9: 1304.
Hae-Lim Cha; Jae-Woo Ko; Jong-Rok Lim; David-Kwangsoon Kim; Hyung-Keun Ahn. Performance Ratio of Crystalline Si and Triple Junction a-Si Thin Film Photovoltaic Modules for the Application to BIPVs. Transactions on Electrical and Electronic Materials 2017, 18, 30 -34.
AMA StyleHae-Lim Cha, Jae-Woo Ko, Jong-Rok Lim, David-Kwangsoon Kim, Hyung-Keun Ahn. Performance Ratio of Crystalline Si and Triple Junction a-Si Thin Film Photovoltaic Modules for the Application to BIPVs. Transactions on Electrical and Electronic Materials. 2017; 18 (1):30-34.
Chicago/Turabian StyleHae-Lim Cha; Jae-Woo Ko; Jong-Rok Lim; David-Kwangsoon Kim; Hyung-Keun Ahn. 2017. "Performance Ratio of Crystalline Si and Triple Junction a-Si Thin Film Photovoltaic Modules for the Application to BIPVs." Transactions on Electrical and Electronic Materials 18, no. 1: 30-34.
Jae-Woo Ko; Jong-Log Lim; David K. Kim; Hae-Lim Cha; Si-Han Kim; Chang-Koo Lee; Hyung-Keun Ahn. Analysis of Grounding Resistance for Zero Energy Town Floating PV System Using Underground Wiring. Journal of the Korean Institute of Electrical and Electronic Material Engineers 2016, 29, 303 -306.
AMA StyleJae-Woo Ko, Jong-Log Lim, David K. Kim, Hae-Lim Cha, Si-Han Kim, Chang-Koo Lee, Hyung-Keun Ahn. Analysis of Grounding Resistance for Zero Energy Town Floating PV System Using Underground Wiring. Journal of the Korean Institute of Electrical and Electronic Material Engineers. 2016; 29 (5):303-306.
Chicago/Turabian StyleJae-Woo Ko; Jong-Log Lim; David K. Kim; Hae-Lim Cha; Si-Han Kim; Chang-Koo Lee; Hyung-Keun Ahn. 2016. "Analysis of Grounding Resistance for Zero Energy Town Floating PV System Using Underground Wiring." Journal of the Korean Institute of Electrical and Electronic Material Engineers 29, no. 5: 303-306.