The Experts below are selected from a list of 2016 Experts worldwide ranked by ideXlab platform
Bala Pesala - One of the best experts on this subject based on the ideXlab platform.
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tuning the solar power generation curve by optimal design of solar tree orientations
2020Co-Authors: Madan Kumar Lakshmanan, Bala PesalaAbstract:The paper presents a new design of a solar tree where solar panels are appropriately positioned like the leaves of a tree. Compared to fixed orientation solar panels, the main advantage of a solar tree is the ability to optimize the orientation of individual solar leaves in order to tune the power generation curves as required, for example, increasing the energy production during the winter months when solar insolation is low. Since orientation of solar panels is the key to achieve the maximum productivity of solar photovoltaic (PV) plants, data-driven and location-specific approach is employed to determine optimal orientation of five solar panels for solar tree structure for seven locations covering a large Latitude range. Compared to the commonly employed Latitude Tilt orientation for solar PV modules, optimal solar tree design shows the feasibility of tuning the power generation curves to increase the power production in winter months or any other desired months. Scope for such tuning is higher for locations having high direct normal irradiance (DNI) and high standard deviation in the solar insolation curve. Also, higher number of solar panels in a solar tree provides higher degrees of freedom and hence larger flexibility to tune the power generation curve.
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optimal solar tree design for increased flexibility in seasonal energy extraction
Renewable Energy, 2018Co-Authors: Madan Kumar Lakshmanan, Bala Pesala, Sumon DeyAbstract:Abstract The paper proposes location/application specific tuning of the solar power generation curve by appropriately orienting solar panels in a solar tree. The initial part of the study involving optimization of single panel orientation, emphasizes the need to adopt data driven approach. Study carried out for 15 locations covering a large Latitude range shows that optimal orientation cannot be determined based on the Latitude angle alone and azimuth angle also needs to be considered, especially for locations having asymmetric solar insolation pattern during a day. Based on these insights, feasibility of tuning annual solar power generation curve is shown by designing a 1 kW solar tree for four locations. Genetic algorithm based optimization is used for positioning of the solar panels so that shadow losses are minimized. Validation with ray optic simulations for solar trees designed for two locations have shown less than 2% shading losses. The optimized solar trees for San Francisco and Paris show increase in power generation of 2.04% and 7.38% respectively compared to Latitude Tilt. The simulations are further validated using a scaled down prototype solar tree showing excellent match. The methodology presented here can be easily extended to the design of optimized solar tree for any location and capacity.
Sumon Dey - One of the best experts on this subject based on the ideXlab platform.
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optimal solar tree design for increased flexibility in seasonal energy extraction
Renewable Energy, 2018Co-Authors: Madan Kumar Lakshmanan, Bala Pesala, Sumon DeyAbstract:Abstract The paper proposes location/application specific tuning of the solar power generation curve by appropriately orienting solar panels in a solar tree. The initial part of the study involving optimization of single panel orientation, emphasizes the need to adopt data driven approach. Study carried out for 15 locations covering a large Latitude range shows that optimal orientation cannot be determined based on the Latitude angle alone and azimuth angle also needs to be considered, especially for locations having asymmetric solar insolation pattern during a day. Based on these insights, feasibility of tuning annual solar power generation curve is shown by designing a 1 kW solar tree for four locations. Genetic algorithm based optimization is used for positioning of the solar panels so that shadow losses are minimized. Validation with ray optic simulations for solar trees designed for two locations have shown less than 2% shading losses. The optimized solar trees for San Francisco and Paris show increase in power generation of 2.04% and 7.38% respectively compared to Latitude Tilt. The simulations are further validated using a scaled down prototype solar tree showing excellent match. The methodology presented here can be easily extended to the design of optimized solar tree for any location and capacity.
Madan Kumar Lakshmanan - One of the best experts on this subject based on the ideXlab platform.
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tuning the solar power generation curve by optimal design of solar tree orientations
2020Co-Authors: Madan Kumar Lakshmanan, Bala PesalaAbstract:The paper presents a new design of a solar tree where solar panels are appropriately positioned like the leaves of a tree. Compared to fixed orientation solar panels, the main advantage of a solar tree is the ability to optimize the orientation of individual solar leaves in order to tune the power generation curves as required, for example, increasing the energy production during the winter months when solar insolation is low. Since orientation of solar panels is the key to achieve the maximum productivity of solar photovoltaic (PV) plants, data-driven and location-specific approach is employed to determine optimal orientation of five solar panels for solar tree structure for seven locations covering a large Latitude range. Compared to the commonly employed Latitude Tilt orientation for solar PV modules, optimal solar tree design shows the feasibility of tuning the power generation curves to increase the power production in winter months or any other desired months. Scope for such tuning is higher for locations having high direct normal irradiance (DNI) and high standard deviation in the solar insolation curve. Also, higher number of solar panels in a solar tree provides higher degrees of freedom and hence larger flexibility to tune the power generation curve.
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optimal solar tree design for increased flexibility in seasonal energy extraction
Renewable Energy, 2018Co-Authors: Madan Kumar Lakshmanan, Bala Pesala, Sumon DeyAbstract:Abstract The paper proposes location/application specific tuning of the solar power generation curve by appropriately orienting solar panels in a solar tree. The initial part of the study involving optimization of single panel orientation, emphasizes the need to adopt data driven approach. Study carried out for 15 locations covering a large Latitude range shows that optimal orientation cannot be determined based on the Latitude angle alone and azimuth angle also needs to be considered, especially for locations having asymmetric solar insolation pattern during a day. Based on these insights, feasibility of tuning annual solar power generation curve is shown by designing a 1 kW solar tree for four locations. Genetic algorithm based optimization is used for positioning of the solar panels so that shadow losses are minimized. Validation with ray optic simulations for solar trees designed for two locations have shown less than 2% shading losses. The optimized solar trees for San Francisco and Paris show increase in power generation of 2.04% and 7.38% respectively compared to Latitude Tilt. The simulations are further validated using a scaled down prototype solar tree showing excellent match. The methodology presented here can be easily extended to the design of optimized solar tree for any location and capacity.
R K Ulrich - One of the best experts on this subject based on the ideXlab platform.
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long term measurements of sunspot magnetic Tilt angles
The Astrophysical Journal, 2012Co-Authors: R K UlrichAbstract:Tilt angles of close to 30,600 sunspots are determined using Mount Wilson daily averaged magnetograms taken from 1974 to 2012, and SOHO/MDI magnetograms taken from 1996 to 2010. Within a cycle, more than 90% of sunspots have a normal polarity alignment along the east-west direction following Hale's law. The median Tilts increase with increasing Latitude (Joy's law) at a rate of ~05 per degree of Latitude. Tilt angles of spots appear largely invariant with respect to time at a given Latitude, but they decrease by ~09 per year on average, a trend that largely reflects Joy's law following the butterfly diagram. We find an asymmetry between the hemispheres in the mean Tilt angles. On average, the Tilts are greater in the Southern than in the Northern Hemisphere for all Latitude zones, and the differences increase with increasing Latitude.
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long term measurements of sunspot magnetic Tilt angles
arXiv: Solar and Stellar Astrophysics, 2012Co-Authors: R K UlrichAbstract:Tilt angles of close to 30,600 sunspots are determined using Mount Wilson daily averaged magnetograms taken from 1974 to 2012, and MDI/SoHO magnetograms taken from 1996 to 2010. Within a cycle, more than 90% of sunspots have a normal polarity alignment along the east-west direction following Hale's law. The median Tilts increase with increasing Latitude (Joy's law) at a rate of ~0.5 degree per degree of Latitude. Tilt angles of spots appear largely invariant with respect to time at a given Latitude, but they decrease by ~0.9degree per year on average, a trend which largely reflects Joy's law following the butterfly diagram. We find an asymmetry between the hemispheres in the mean Tilt angles. On average, the Tilts are greater in the southern than in the northern hemisphere for all Latitude zones, and the differences increase with increasing Latitude.
S Soulayman - One of the best experts on this subject based on the ideXlab platform.
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optimum Tilt angle and maximum possible solar energy gain at high Latitude zone
Journal of Solar Energy Research, 2016Co-Authors: S SoulaymanAbstract:The performance of a solar collector is highly dependent on its Tilt angle with the horizon. The variation of Tilt angle changes the amount of solar radiation reaching the collector surface. Meanwhile, is the rule of thumb, which says that solar collector should be orientated towards the Equator with a Tilt equal to Latitude, is valid for high Latitudes region? Thus, it is required to determine the optimum Tilt for Equator facing collectors. In addition, the question that may arise: how many times is reasonable for adjusting collector Tilt angle for Equator facing collectors? A mathematical model was used for estimating the solar radiation on a Tilted surface, and to determine the optimum Tilt angle and orientation (surface azimuth angle) for the solar collector at any Latitude. This model was applied for determining optimum Tilt angle in the high Latitudes zone in the Southern and Northern Hemispheres, on a daily basis, as well as for a specific period. The optimum angle was computed by searching for the values for which the radiation on the collector surface is a maximum for a particular day or a specific period. The solar radiation on the collector surface of optimum Tilt angle, of Latitude Tilt angle and of null Tilt angle was calculated for a particular day or a specific period. The results reveal that changing the Tilt angle 12 times in a year (i.e. using the monthly optimum Tilt angle) maintains approximately the total amount of solar radiation near the maximum value that is found by changing the Tilt angle daily to its optimum value. This achieves a yearly gain in solar radiation up to several times of the case of a horizontal surface depending on the Latitude value.
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optimum Tilt angle of solar collectors for building applications in mid Latitude zone
Energy Conversion and Management, 2016Co-Authors: S Soulayman, M HammoudAbstract:Abstract For the middle Latitudes (mid-Latitude) zone (Latitudes between 23.45°N and 43.45°N and between 23.45°S and 43.45°S), as rules of thumb first solar collector should be orientated toward Equator and second it should have a Latitude Tilt value; however are these statements valid all over the year? The present work focuses on presenting an algorithm for determining the optimum Tilt angle over mid-Latitude zone and for any collector azimuth angle. Moreover, two simple approximate equations are proposed for predicting daily optimum Tilt angle and optimum Tilt angle for any number of consecutive months. The present algorithm was applied at different Latitudes where data are available. The different yearly possible energy gains in relation that received by a horizontal surface were calculated. It is found that the yearly daily average energy gain for daily, monthly, seasonally and half-yearly adjustments are approximately constant. For the Latitude of 43.45°N it reaches 1.7 times that of horizontal surface. So, it is sufficient from practical point of view to adjust the solar collector Tilt angle twice a year: once on 22/3 and the other on 22/9. Moreover, the first rule of thumb is valid however the second one is not applicable for a large number of consecutive days in the year.