• International journal of advanced smart convergence
• /
• v.4 no.1
• /
• pp.104-113
• /
• 2015

This paper focuses on a temperature effects on a PV panel which has been installed in Thailand. The main objective is cleaning PV panels and reduce temperature of PV panel by water injects from waterway and experimental results of PV power what it is difference. This project is designed by PLC control system which water injects and control PV temperature, In addition, this project consists of hardware and software such as water pump, water injection and PLC control has been automatically and it can be control system manually. The automatic control system is working when PV temperature rises up over 45 degree Celsius after that the pumping machine would inject water to the surface of PV panels and it must be stop when the PV panel temperature comes down less than 45 degree Celsius. The result of actual experimental found that the control system has been done correctly under specify condition. The experimental has been shown electrical data before and after water injects on PV system found that the electrical power a bit increases and The energy has been taken from PV panel less than energy consumption equipment of control system which taken to operate the water injecting system.

• 한국전산유체공학회:학술대회논문집
• /
• 2009.04a
• /
• pp.142-147
• /
• 2009

COMS (Communication, Ocean and Meteorological Satellite) is a geostationary satellite and has been developing by KARI for communication, ocean and meteorological observations. It will be tested under vacuum condition and very low temperature in order to verify thermal design of COMS. The test will be performed by using KARI large thermal vacuum chamber, which was developed by KARI, and the COMS will be the first flight satellite tested in this chamber. The purposes of thermal balance test are to correlate analytical model used for design evaluation and predicting temperatures, and to verify and adjust thermal control concept. KARI has plan to use heating plates to simulate space hot condition especially for radiator panels such as north and south panels. They will be controlled from 90K to 273K by circulating GN2 and LN2 alternatively according to the test phases, while the shroud of the vacuum chamber will be under constant temperature, 90K, during all thermal balance test. This paper presents thermal modelling including test chamber, heating plates and the satellite without solar array wing and Ka-band reflectors and discusses temperature prediction during thermal balance test.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.407-408
• /
• 2013

Thin transparent conductive oxides (TCOs) having a thickness lower than 30 nm have been widely usedin touch screen panels. However the resistivity of the TCO films significantly increases as the thickness decreases, due to the poor crystallinity at very thin thickness of TCO films. In this study, we have investigated the effect of electron beam irradiation during the sputtering on the electrical properties and transmittance of 30 nm-thick ITO films, which have a different SnO2 atomic percent, prepared by magnetron sputtering at room temperature. Fig. 1 shows the variation of resistivity of ITO films with a different SnO2 atomic percent for both the normal ITO films and electron beam irradiated ITO films. As shows in Fig. 1, the electron beam irradiation to the ITO (SnO2 weight percent 10%) films during the sputtering resulted in a significantly decreased in resistivity from $7.4{\times}10^{-4}{\Omega}-cm$ to $1.5{\times}10^{-4}{\Omega}-cm$ and it also increased in transmittance from 84% to 88% at a wavelength of 550 nm. These results can be attributed to energy transfer from electron to ad-atoms of ITO films during the electron beam irradiated sputtering, which can enhance the crystallinity of 30 nm-thick ITO films. It is strongly indicate that electron beam irradiation can greatly improve the electrical properties and transmittance of very thin ITO films for touch screen panels, flexible displays and solar cells.

• Structural Engineering and Mechanics
• /
• v.62 no.4
• /
• pp.465-475
• /
• 2017

Photovoltaic (PV) panels are used in high-rise buildings to convert solar energy to electricity. Due to the considerable energy consumption of high-rise buildings, applying PV technology is of great significance to energy saving. In the application of PV panels, one of the most important construction issues is the connection of the PV panel with the main structures. One major difficulty of the connection design is that the PV panel connection consists of two separate components with coupling and indeterminate dimension. In this paper, the gap element is employed in these two separated but coupled components, i.e., hook and catch. Topology optimization is applied to optimize and design the cross-section of the PV panel connection. Pareto optimization is conducted to operate the optimization subject to multiple load scenarios. The initial design for the topology optimization is determined by the common design specified by the Technical Code for Glass Curtain Wall Engineering (JGJ 102-2003). Gravity and wind load scenarios are considered for the optimization and numerical analysis. Post analysis is conducted for the optimal design obtained by the topology optimization due to the manufactory requirements. Generally, compared with the conventional design, the optimized connector reduces material use with improved structural characteristics.

• New & Renewable Energy
• /
• v.17 no.1
• /
• pp.19-32
• /
• 2021

Photovoltaic (PV) panels are generally treated as the most dependable components of PV systems; therefore, investigations are necessary to understand and emphasize the degradation of PV cells. In almost all specific deprivation models, humidity and temperature are the two major factors that are responsible for PV module degradation. However, even if the degradation mode of a PV module is determined, it is challenging to research them in practice. Long-term response experiments should thus be conducted to investigate the influences of the incidence, rates of change, and different degradation methods of PV modules on energy production; such models can help avoid lengthy experiments to investigate the degradation of PV panels under actual working conditions. From the review, it was found that the degradation rate of PV modules in climates where the annual average ambient temperature remained low was -1.05% to -1.16% per year, and the degree of deterioration of PV modules in climates with high average annual ambient temperatures was -1.35% to -1.46% per year; however, PV manufacturers currently claim degradation rates of up to -0.5% per year.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.42 no.1
• /
• pp.41-49
• /
• 2014

This study spatially assesses the impact of trees on residential rooftop solar energy potential using urban three-dimensional models derived from Light Detection and Ranging(LiDAR) data in San Francisco, California. In recent years on-site solar energy generation in cities has become an essential agenda in municipal climate action plans. However, it can be limited by neighboring environments such as shade from topography, buildings and trees. Of all these effects, the impact of trees on rooftop photovoltaics(PVs) requires careful attention because improper situation of solar panels without considering trees can result in inefficient solar energy generation, tree removal, and/or increasing building energy demand and urban heat island effect. Using ArcMap 9.3.1, we calculated the incoming annual solar radiation on individual rooftops in San Francisco and the reduced insolation affected by trees. Furthermore, we performed a multiple regression analysis to see what attributes of trees in a neighborhood(tree density, tree heights, and the variance of tree heights) affect rooftop insolation. The result shows that annual total residential rooftops insolation in San Francisco is 18,326,671 MWh and annual total light-loss reduction caused by trees is 326,406 MWh, which is about 1.78%. The annual insolation shows a wide range of values from $34.4kWh/m^2/year$ to $1,348.4kWh/m^2/year$. The result spatially maps the locations that show the various levels of impact from trees. The result from multiple regression shows that tree density, average tree heights and the variation of tree heights in a neighborhood have statistically significant effects on the rooftop solar potential. The results can be linked to municipal energy planning in order to manage potential conflicts as cities with low to medium population density begin implementing on-site solar energy generation. Rooftop solar energy generation makes the best contribution towards achieving sustainability when PVs are optimally located while pursuing the preservation of urban trees.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.5
• /
• pp.585-591
• /
• 2020

In accordance with the government's expansion of solar power generation, the installation of solar panels is expected to expand in Korea. On the other hand, policy discussions on the establishment of a domestic post-management system for waste from photovoltaic power are insufficient. This study estimated the benefit-cost of solar PV Panel recycling and derived the implications for the photovoltaic waste policies in Korea. Overall, the profitability of the recycling project is very low when the project execution period is 10 years. On the other hand, the economic efficiency of the project can be sufficiently high when the duration of the solar panel recycling project is extended to 20 years. In the short term, it is challenging to expect voluntary companies to enter this recycling business because of low economic efficiency. Therefore, it is necessary to prepare various policies to improve the economic efficiency of the recycling business. In conclusion, the following policy implications for PV panel recycling activation are proposed: i) legislation for the recycling of waste solar photovoltaic panel, ii) designation of Association for Solar Panel waste monitoring, and iii) expansion of R & D and the development of various business models related to solar recycling.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.31 no.4
• /
• pp.53-59
• /
• 2003

Strain Energy Hinge(SEH) has been used in Korea Multi-purpose Satellite(KOMPSAT) series to deploy the solar panel due to the good record of reliability. However, when it reached a desired deployment position, a large buckling force is applied to the main body. This may cause structural damage and also affect control of the satellite. Therefore, reliable dynamic analysis for the deployment system is required at a design stage. Moreover, various mission of a satellite has made the size of solar panels got bigger, so elastic effect has to be considered seriously to get more precise analysis results. In this paper, a dynamic analysis method to predict the deployment is verified by KOMPSAT-2 deployment test.

• Journal of the Korean Ceramic Society
• /
• v.51 no.3
• /
• pp.170-176
• /
• 2014

Effective glass frit compositions enabled to absorb laser energy, and to seal a commercial dye-sensitized solar-cell-panel substrate were developed by using $V_2O_5$-based glasses with various amounts of $TeO_2$ substitution. The latter was intended to increase the lifetime of the solar cells. Substitution of $V_2O_5$ by $TeO_2$ provided a strong network structure for the glasses via the formation of tetrahedral pyramids in the glass, and changed the various glass properties, such as glass transition temperature ($T_g$), dilatometric softening point ($T_d$), crystallization temperature, coefficient of thermal expansion (CTE), and glass flowage without any detrimental effect on the laser absorption property of the glasses. The thermal expansion mismatch (${\Delta}{\alpha}$) between the glass frit and the substrate could be controlled within less than ${\pm}5%$ by addition of 10 wt% of ${\beta}$-eucryptite. An 810 nm diode laser was used for the sealing test. The laser sealing test revealed that the VZBT20 glass frit with 10 wt% ${\beta}$-eucryptite was successfully sealed the substrates without interfacial cracks and pores. The optimum sealing conditions were provided by a beam size of 3 mm, laser power of 40 watt, scan speed of 300 mm/s, and 200 irradiation cycles.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.22 no.3
• /
• pp.144-151
• /
• 2020

Agrivoltaic systems (AVS) is defined as combining farm-grown crops with photovoltaic panels (PV) installed several meters above the ground. Solar radiation (W/㎡), photosynthetic photon flux density (PPFD, µmol/㎡/s), air temperature (℃), vapor pressure (kPa), soil moisture (㎥/㎥), soil temperature (℃), wind direction (˚), and wind speed (m/s) were measured under the AVS in Boseong-gun during winter barley season. Data was collected by 5 minute interval. All data can download at Github site (https://github.com/chojaeil/AVS_Boseung). To gap-filling missing solar radiation data during about two weeks, the conversion coefficient from solar radiation to PPFD was estimated as 0.41. Further, according to the ratio of diffuse radiation to direct radiation, the maximum value among the twenty PPFD sensors under the AVS was related to the PPFD value of filed.