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John Boland - One of the best experts on this subject based on the ideXlab platform.
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resolution of the cloud enhancement problem for one minute Diffuse radiation prediction
Renewable Energy, 2018Co-Authors: Allan R Starke, Jose M Cardemil, John Boland, Leonardo F L Lemos, Sergio ColleAbstract:Abstract For design and simulation of solar energy systems, quality information about all components of solar irradiance is crucial. In cases when only global irradiance measurements are available, separation models are a useful method to estimate DNI and Diffuse Irradiation. Several of such models have been developed since the 1960s, most of them aiming to deliver estimates in hourly resolution. For higher data resolution, such as in minute data, those models are not able to describe fast transient and cloud enhancement phenomena commonly observed in data with smaller time-steps. This paper proposes an adaptation of the BRL separation model, making it capable of delivering more precise irradiance estimates for higher resolution data. Two models result from this adaptation: one for Brazil and other for Australia. The proposed models yield a more precise DNI and Diffuse fraction estimates to their respective countries, compared to other separation models commonly used in the technical literature. For example, using the recommended Combined Performance Index (CPI) as a single statistical indicator, the proposed model yields DNI estimates with CPI from 230 to 350% for Australia, and from 270 to 800% for Brazil, while the Engerer model, recently recommended as a ‘‘quasi-universal” 1-min separation model, yields DNI estimates with CPI from 500 to 700% for Australia, and from 600 to 1800% for Brazil.
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solar energy resource assessment in chile satellite estimation and ground station measurement
Energy Procedia, 2014Co-Authors: Rodrigo Escobar, Fernando Ramos Martins, Enio Bueno Pereira, Alberto Ortega, Cristian E Cortes, Alan Pinot, John BolandAbstract:Abstract The progress from the last four years in solar energy resource assessment for Chile is reported, including measurements from a ground station network spanning from two to three years of data, and satellite estimations from the recently developed Chile-SR model including two full years of data. The model introduces different treatments for the meteorological variables and the effective cloud cover computations which allow estimation of the global horizontal Irradiation on an hourly basis. The BRL model of Diffuse radiation is then applied in order to estimate the Diffuse fraction and Diffuse Irradiation, from which the Direct horizontal Irradiation is then computed. Direct normal Irradiation is computed by applying proper solar geometry corrections to the direct horizontal Irradiation. The satellite estimation model was developed as an adaptation from Brazil-SR model, with an improved formulation for altitude-corrected atmospheric parameters, and a novel formulation for calculating effective cloud covers while at the same time detecting and differentiating it from snow covers and salt lakes. The model is validated by comparison with ground station data. The results indicate that there are high radiation levels throughout the country. In particular, northern Chile is endowed with one of the highest solar resources in the world, although the resource variability is higher than previously thought.
Jose M Cardemil - One of the best experts on this subject based on the ideXlab platform.
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resolution of the cloud enhancement problem for one minute Diffuse radiation prediction
Renewable Energy, 2018Co-Authors: Allan R Starke, Jose M Cardemil, John Boland, Leonardo F L Lemos, Sergio ColleAbstract:Abstract For design and simulation of solar energy systems, quality information about all components of solar irradiance is crucial. In cases when only global irradiance measurements are available, separation models are a useful method to estimate DNI and Diffuse Irradiation. Several of such models have been developed since the 1960s, most of them aiming to deliver estimates in hourly resolution. For higher data resolution, such as in minute data, those models are not able to describe fast transient and cloud enhancement phenomena commonly observed in data with smaller time-steps. This paper proposes an adaptation of the BRL separation model, making it capable of delivering more precise irradiance estimates for higher resolution data. Two models result from this adaptation: one for Brazil and other for Australia. The proposed models yield a more precise DNI and Diffuse fraction estimates to their respective countries, compared to other separation models commonly used in the technical literature. For example, using the recommended Combined Performance Index (CPI) as a single statistical indicator, the proposed model yields DNI estimates with CPI from 230 to 350% for Australia, and from 270 to 800% for Brazil, while the Engerer model, recently recommended as a ‘‘quasi-universal” 1-min separation model, yields DNI estimates with CPI from 500 to 700% for Australia, and from 600 to 1800% for Brazil.
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solar energy resource assessment in chile satellite estimation and ground station measurements
Renewable Energy, 2014Co-Authors: Rodrigo Escobar, Fernando Ramos Martins, Enio Bueno Pereira, Cristian Cortes, Alan Pino, Jose M CardemilAbstract:The progress from the last four years in solar energy resource assessment for Chile is reported, including measurements from a ground station network spanning from two to three years of data, and satellite estimations from the recently developed Chile-SR model including two full years of data. The model introduces different procedures for the meteorological variables and the effective cloud cover computations that allow estimation of the global horizontal and Diffuse Irradiation on an hourly basis. Direct normal Irradiation is computed by applying proper solar geometry corrections to the direct horizontal Irradiation. The satellite estimation model was developed as an adaptation from Brazil-SR model, with an improved formulation for altitude-corrected atmospheric parameters, and a novel formulation for calculating effective cloud covers while at the same time detecting and differentiating it from snow covers and salt lakes. The model is validated by comparison with ground station data. The results indicate that there are high radiation levels throughout the country. In particular, northern Chile is endowed with one of the highest solar resources in the world.
Rodrigo Escobar - One of the best experts on this subject based on the ideXlab platform.
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solar energy resource assessment in chile satellite estimation and ground station measurements
Renewable Energy, 2014Co-Authors: Rodrigo Escobar, Fernando Ramos Martins, Enio Bueno Pereira, Cristian Cortes, Alan Pino, Jose M CardemilAbstract:The progress from the last four years in solar energy resource assessment for Chile is reported, including measurements from a ground station network spanning from two to three years of data, and satellite estimations from the recently developed Chile-SR model including two full years of data. The model introduces different procedures for the meteorological variables and the effective cloud cover computations that allow estimation of the global horizontal and Diffuse Irradiation on an hourly basis. Direct normal Irradiation is computed by applying proper solar geometry corrections to the direct horizontal Irradiation. The satellite estimation model was developed as an adaptation from Brazil-SR model, with an improved formulation for altitude-corrected atmospheric parameters, and a novel formulation for calculating effective cloud covers while at the same time detecting and differentiating it from snow covers and salt lakes. The model is validated by comparison with ground station data. The results indicate that there are high radiation levels throughout the country. In particular, northern Chile is endowed with one of the highest solar resources in the world.
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solar energy resource assessment in chile satellite estimation and ground station measurement
Energy Procedia, 2014Co-Authors: Rodrigo Escobar, Fernando Ramos Martins, Enio Bueno Pereira, Alberto Ortega, Cristian E Cortes, Alan Pinot, John BolandAbstract:Abstract The progress from the last four years in solar energy resource assessment for Chile is reported, including measurements from a ground station network spanning from two to three years of data, and satellite estimations from the recently developed Chile-SR model including two full years of data. The model introduces different treatments for the meteorological variables and the effective cloud cover computations which allow estimation of the global horizontal Irradiation on an hourly basis. The BRL model of Diffuse radiation is then applied in order to estimate the Diffuse fraction and Diffuse Irradiation, from which the Direct horizontal Irradiation is then computed. Direct normal Irradiation is computed by applying proper solar geometry corrections to the direct horizontal Irradiation. The satellite estimation model was developed as an adaptation from Brazil-SR model, with an improved formulation for altitude-corrected atmospheric parameters, and a novel formulation for calculating effective cloud covers while at the same time detecting and differentiating it from snow covers and salt lakes. The model is validated by comparison with ground station data. The results indicate that there are high radiation levels throughout the country. In particular, northern Chile is endowed with one of the highest solar resources in the world, although the resource variability is higher than previously thought.
Uwe Feister - One of the best experts on this subject based on the ideXlab platform.
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Reconstruction of daily solar UV Irradiation from 1893 to 2002 in Potsdam, Germany
International Journal of Biometeorology, 2007Co-Authors: Jürgen Junk, Uwe Feister, Alfred HelbigAbstract:Long-term records of solar UV radiation reaching the Earth’s surface are scarce. Radiative transfer calculations and statistical models are two options used to reconstruct decadal changes in solar UV radiation from long-term records of measured atmospheric parameters that contain information on the effect of clouds, atmospheric aerosols and ground albedo on UV radiation. Based on earlier studies, where the long-term variation of daily solar UV Irradiation was derived from measured global and Diffuse Irradiation as well as atmospheric ozone by a non-linear regression method [Feister et al. ( 2002 ) Photochem Photobiol 76:281–293], we present another approach for the reconstruction of time series of solar UV radiation. An artificial neural network (ANN) was trained with measurements of solar UV Irradiation taken at the Meteorological Observatory in Potsdam, Germany, as well as measured parameters with long-term records such as global and Diffuse radiation, sunshine duration, horizontal visibility and column ozone. This study is focussed on the reconstruction of daily broad-band UV-B (280–315 nm), UV-A (315–400 nm) and erythemal UV Irradiation (ER). Due to the rapid changes in cloudiness at mid-latitude sites, solar UV irradiance exhibits appreciable short-term variability. One of the main advantages of the statistical method is that it uses doses of highly variable input parameters calculated from individual spot measurements taken at short time intervals, which thus do represent the short-term variability of solar irradiance.
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reconstruction of daily solar uv Irradiation by an artificial neural network ann
Remote Sensing, 2006Co-Authors: Uwe Feister, Jürgen JunkAbstract:Long-term records of solar UV radiation reaching the Earth's surface are scarce. Radiative transfer calculations and statistical models are two options to re-construct decadal changes in solar UV radiation from long-term records of measured atmospheric parameters that contain information on the effect of clouds, atmospheric aerosols and ground albedo on UV radiation. Based on earlier studies, where the long-term variation of daily solar UV Irradiation was derived from measured global and Diffuse Irradiation as well as atmospheric ozone by a non-linear regression method (1) have chosen another approach for the re-construction of time series of solar UV radiation. An Artificial Neural Network (ANN) has been trained with measurements of solar UV Irradiation taken at the Observatories Potsdam and Lindenberg in Germany as well as measured parameters with long-term records such as global and Diffuse radiation, sunshine duration, horizontal visibility and column ozone. This study is focused on the re-construction of daily broad-band UV-B (280 - 315 nm), UV-A (315 - 400 nm) and erythemal UV Irradiation (ER). Due to fast changes in cloudiness at mid-latitude sites, solar UV irradiance shows an appreciable short-term variability. One of the main advantages of the statistical method is that it uses doses of highly variable input parameters calculated from individual spot measurements that are taken at short time steps, and thus do contain the short-term variability of solar irradiance. Our study has been supported by the European SCOUT-03 project funding. The ANN model results have been evaluated within the European action COST726 (2 ).
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parameterization of daily solar global ultraviolet Irradiation
Photochemistry and Photobiology, 2002Co-Authors: Uwe Feister, E Jakel, K GerickeAbstract:Abstract Daily values of solar global ultraviolet (UV) B and UVA Irradiation as well as erythemal Irradiation have been parameterized to be estimated from pyranometer measurements of daily global and Diffuse Irradiation as well as from atmospheric column ozone. Data recorded at the Meteorological Observatory Potsdam (52°N, 107 m asl) in Germany over the time period 1997–2000 have been used to derive sets of regression coefficients. The validation of the method against independent data sets of measured UV Irradiation shows that the parameterization provides a gain of information for UVB, UVA and erythemal Irradiation referring to their averages. A comparison between parameterized daily UV Irradiation and independent values of UV Irradiation measured at a mountain station in southern Germany (Meteorological Observatory Hohenpeissenberg at 48°N, 977 m asl) indicates that the parameterization also holds even under completely different climatic conditions. On a long-term average (1953–2000), parameterized annu...
Fernando Ramos Martins - One of the best experts on this subject based on the ideXlab platform.
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solar energy resource assessment in chile satellite estimation and ground station measurements
Renewable Energy, 2014Co-Authors: Rodrigo Escobar, Fernando Ramos Martins, Enio Bueno Pereira, Cristian Cortes, Alan Pino, Jose M CardemilAbstract:The progress from the last four years in solar energy resource assessment for Chile is reported, including measurements from a ground station network spanning from two to three years of data, and satellite estimations from the recently developed Chile-SR model including two full years of data. The model introduces different procedures for the meteorological variables and the effective cloud cover computations that allow estimation of the global horizontal and Diffuse Irradiation on an hourly basis. Direct normal Irradiation is computed by applying proper solar geometry corrections to the direct horizontal Irradiation. The satellite estimation model was developed as an adaptation from Brazil-SR model, with an improved formulation for altitude-corrected atmospheric parameters, and a novel formulation for calculating effective cloud covers while at the same time detecting and differentiating it from snow covers and salt lakes. The model is validated by comparison with ground station data. The results indicate that there are high radiation levels throughout the country. In particular, northern Chile is endowed with one of the highest solar resources in the world.
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solar energy resource assessment in chile satellite estimation and ground station measurement
Energy Procedia, 2014Co-Authors: Rodrigo Escobar, Fernando Ramos Martins, Enio Bueno Pereira, Alberto Ortega, Cristian E Cortes, Alan Pinot, John BolandAbstract:Abstract The progress from the last four years in solar energy resource assessment for Chile is reported, including measurements from a ground station network spanning from two to three years of data, and satellite estimations from the recently developed Chile-SR model including two full years of data. The model introduces different treatments for the meteorological variables and the effective cloud cover computations which allow estimation of the global horizontal Irradiation on an hourly basis. The BRL model of Diffuse radiation is then applied in order to estimate the Diffuse fraction and Diffuse Irradiation, from which the Direct horizontal Irradiation is then computed. Direct normal Irradiation is computed by applying proper solar geometry corrections to the direct horizontal Irradiation. The satellite estimation model was developed as an adaptation from Brazil-SR model, with an improved formulation for altitude-corrected atmospheric parameters, and a novel formulation for calculating effective cloud covers while at the same time detecting and differentiating it from snow covers and salt lakes. The model is validated by comparison with ground station data. The results indicate that there are high radiation levels throughout the country. In particular, northern Chile is endowed with one of the highest solar resources in the world, although the resource variability is higher than previously thought.