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Christian A Gueymard - One of the best experts on this subject based on the ideXlab platform.
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optimal combination of gridded and ground observed solar radiation Data for regional solar resource assessment
Solar Energy, 2015Co-Authors: J A Ruizarias, S Quesadaruiz, Eduardo F. Fernandez, Christian A GueymardAbstract:Abstract Proper quantification of the available solar resource is essential for the diverse development phases of any solar power plant. At local scale, the solar resource is best assessed from ground radiometric stations. At regional-to-continental scales, however, satellite-based techniques are currently the most suitable approach. Solar radiation evaluation using numerical weather prediction (NWP) models presents some advantages over satellite-based techniques. Nonetheless, gridded solar radiation estimates using either satellite-based or NWP-based techniques still produce biased estimates which are often much higher for the latter. Therefore, a correction needs to be applied before these gridded values are usable for solar applications, especially for NWP-based estimates. This contribution introduces an original method based on the optimal interpolation technique to adjust gridded solar radiation estimates consistently with concomitant radiometric ground observations. The method’s performance is demonstrated using NWP-based gridded estimates with 10-km spacing of global and direct monthly Irradiation Data during the 10-year period from 2003 to 2012 over continental Spain and the Balearic Islands. It is shown that the proposed methodology produces adjusted gridded values that are (or nearly always are, in the case of direct Irradiation) within the expected measurement uncertainty of the ground observations, provided a sufficiently large number of observations is available for correction. For the studied region and these NWP-based gridded Datasets, our findings suggest that a homogeneous mean distance between ground observations of 100–150 km can result in unbiased gridded estimates.
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prediction and performance assessment of mean hourly global radiation
Solar Energy, 2000Co-Authors: Christian A GueymardAbstract:Abstract Using a large Dataset of 135 stations encompassing very diverse geographic locations (82.5°N to 67.6°S) and climates, two new models are presented to predict the monthly-average hourly global Irradiation distribution from its daily counterpart. It is found that a quadratic in the sine of solar elevation fits the Data very well at all locations. Other parameters include the mean monthly clearness index, Kt, the average day length, and the daily average solar elevation. Based on this Dataset, a detailed performance assessment is conducted for these new models, as well as for six models of the literature. Their respective performance is discussed, particularly with respect to the latitudinal effect. The proposed models appear to correctly predict Irradiations even for a very low sun typical of near-polar night conditions. The accurate predictions of the newly proposed ‘daily integration model’ translate into the lowest yearly-average and site-average Root Mean Square Difference, a statistic obtained by comparison with 21 722 measured hourly Irradiations. However, it is stressed that the performance of this kind of model is seriously limited by artefacts due to shading (e.g., from mountains), and, more importantly, by strong morning/afternoon radiative asymmetries due to local or climatological influences, which cannot be predicted from just daily Irradiation Data.
Gustavo Caceres - One of the best experts on this subject based on the ideXlab platform.
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concentrated solar power plants review and design methodology
Renewable & Sustainable Energy Reviews, 2013Co-Authors: Huili Zhang, Jan Baeyens, Jan Degrève, Gustavo CaceresAbstract:Concentrated solar power plants (CSPs) are gaining increasing interest, mostly as parabolic trough collectors (PTC) or solar tower collectors (STC). Notwithstanding CSP benefits, the daily and monthly variation of the solar Irradiation flux is a main drawback. Despite the approximate match between hours of the day where solar radiation and energy demand peak, CSPs experience short term variations on cloudy days and cannot provide energy during night hours unless incorporating thermal energy storage (TES) and/or backup systems (BS) to operate continuously. To determine the optimum design and operation of the CSP throughout the year, whilst defining the required TES and/or BS, an accurate estimation of the daily solar Irradiation is needed. Local solar Irradiation Data are mostly only available as monthly averages, and a predictive conversion into hourly Data and direct Irradiation is needed to provide a more accurate input into the CSP design. The paper (i) briefly reviews CSP technologies and STC advantages; (ii) presents a methodology to predict hourly beam (direct) Irradiation from available monthly averages, based upon combined previous literature findings and available meteorological Data; (iii) illustrates predictions for different selected STC locations; and finally (iv) describes the use of the predictions in simulating the required plant configuration of an optimum STC.
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concentrated solar power plants review and design methodology
Renewable & Sustainable Energy Reviews, 2013Co-Authors: Huili Zhang, Jan Baeyens, Jan Degrève, Gustavo CaceresAbstract:Abstract Concentrated solar power plants (CSPs) are gaining increasing interest, mostly as parabolic trough collectors (PTC) or solar tower collectors (STC). Notwithstanding CSP benefits, the daily and monthly variation of the solar Irradiation flux is a main drawback. Despite the approximate match between hours of the day where solar radiation and energy demand peak, CSPs experience short term variations on cloudy days and cannot provide energy during night hours unless incorporating thermal energy storage (TES) and/or backup systems (BS) to operate continuously. To determine the optimum design and operation of the CSP throughout the year, whilst defining the required TES and/or BS, an accurate estimation of the daily solar Irradiation is needed. Local solar Irradiation Data are mostly only available as monthly averages, and a predictive conversion into hourly Data and direct Irradiation is needed to provide a more accurate input into the CSP design. The paper (i) briefly reviews CSP technologies and STC advantages; (ii) presents a methodology to predict hourly beam (direct) Irradiation from available monthly averages, based upon combined previous literature findings and available meteorological Data; (iii) illustrates predictions for different selected STC locations; and finally (iv) describes the use of the predictions in simulating the required plant configuration of an optimum STC. The methodology and results demonstrate the potential of CSPs in general, whilst also defining the design background of STC plants.
David G. Dorrell - One of the best experts on this subject based on the ideXlab platform.
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Köppen-Geiger climate classification adjustment of the BRL diffuse Irradiation model for Australian locations
'Elsevier BV', 2021Co-Authors: Jeremy Every, Li L, David G. DorrellAbstract:© 2019 Elsevier Ltd Numerous mathematical models have been developed to estimate diffuse and direct irradiance components based on global Irradiation measurements. The Boland–Ridley–Lauret (BRL) model consists of a single set of parameters for all global locations. There is scope to improve the BRL model to better match local climatic conditions. In this research, the Köppen-Geiger climate classification system is considered to develop a set of adjusted BRL models for Australian conditions. Ground-based and satellite-based Irradiation Data derived from the Australian Bureau of Meteorology are used to tune and test new BRL models developed at a national level and for each climate zone. Irradiation Data are processed through a rigorous quality control procedure before parameter tuning. For ground-based Data, a new national model results in an improvement in 96% of statistical indicators over the original BRL model while Köppen-Geiger zone adjusted models show improvement over the new national model in 72% of the statistics. For satellite-based global Irradiation estimates, a new national BRL model also results in observed improvements, however, no discernible improvement is observed for Köppen-Geiger zone models
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Köppen-Geiger climate classification adjustment of the BRL diffuse Irradiation model for Australian locations
Renewable Energy, 2020Co-Authors: Jeremy Every, David G. DorrellAbstract:Abstract Numerous mathematical models have been developed to estimate diffuse and direct irradiance components based on global Irradiation measurements. The Boland–Ridley–Lauret (BRL) model consists of a single set of parameters for all global locations. There is scope to improve the BRL model to better match local climatic conditions. In this research, the Koppen-Geiger climate classification system is considered to develop a set of adjusted BRL models for Australian conditions. Ground-based and satellite-based Irradiation Data derived from the Australian Bureau of Meteorology are used to tune and test new BRL models developed at a national level and for each climate zone. Irradiation Data are processed through a rigorous quality control procedure before parameter tuning. For ground-based Data, a new national model results in an improvement in 96% of statistical indicators over the original BRL model while Koppen-Geiger zone adjusted models show improvement over the new national model in 72% of the statistics. For satellite-based global Irradiation estimates, a new national BRL model also results in observed improvements, however, no discernible improvement is observed for Koppen-Geiger zone models.
Huili Zhang - One of the best experts on this subject based on the ideXlab platform.
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concentrated solar power plants review and design methodology
Renewable & Sustainable Energy Reviews, 2013Co-Authors: Huili Zhang, Jan Baeyens, Jan Degrève, Gustavo CaceresAbstract:Concentrated solar power plants (CSPs) are gaining increasing interest, mostly as parabolic trough collectors (PTC) or solar tower collectors (STC). Notwithstanding CSP benefits, the daily and monthly variation of the solar Irradiation flux is a main drawback. Despite the approximate match between hours of the day where solar radiation and energy demand peak, CSPs experience short term variations on cloudy days and cannot provide energy during night hours unless incorporating thermal energy storage (TES) and/or backup systems (BS) to operate continuously. To determine the optimum design and operation of the CSP throughout the year, whilst defining the required TES and/or BS, an accurate estimation of the daily solar Irradiation is needed. Local solar Irradiation Data are mostly only available as monthly averages, and a predictive conversion into hourly Data and direct Irradiation is needed to provide a more accurate input into the CSP design. The paper (i) briefly reviews CSP technologies and STC advantages; (ii) presents a methodology to predict hourly beam (direct) Irradiation from available monthly averages, based upon combined previous literature findings and available meteorological Data; (iii) illustrates predictions for different selected STC locations; and finally (iv) describes the use of the predictions in simulating the required plant configuration of an optimum STC.
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concentrated solar power plants review and design methodology
Renewable & Sustainable Energy Reviews, 2013Co-Authors: Huili Zhang, Jan Baeyens, Jan Degrève, Gustavo CaceresAbstract:Abstract Concentrated solar power plants (CSPs) are gaining increasing interest, mostly as parabolic trough collectors (PTC) or solar tower collectors (STC). Notwithstanding CSP benefits, the daily and monthly variation of the solar Irradiation flux is a main drawback. Despite the approximate match between hours of the day where solar radiation and energy demand peak, CSPs experience short term variations on cloudy days and cannot provide energy during night hours unless incorporating thermal energy storage (TES) and/or backup systems (BS) to operate continuously. To determine the optimum design and operation of the CSP throughout the year, whilst defining the required TES and/or BS, an accurate estimation of the daily solar Irradiation is needed. Local solar Irradiation Data are mostly only available as monthly averages, and a predictive conversion into hourly Data and direct Irradiation is needed to provide a more accurate input into the CSP design. The paper (i) briefly reviews CSP technologies and STC advantages; (ii) presents a methodology to predict hourly beam (direct) Irradiation from available monthly averages, based upon combined previous literature findings and available meteorological Data; (iii) illustrates predictions for different selected STC locations; and finally (iv) describes the use of the predictions in simulating the required plant configuration of an optimum STC. The methodology and results demonstrate the potential of CSPs in general, whilst also defining the design background of STC plants.
Lucien Wald - One of the best experts on this subject based on the ideXlab platform.
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Comparison of several Databases of downward solar daily Irradiation Data at ocean surface with PIRATA measurements
European geosciences union general assembly, 2017Co-Authors: Mélodie Trolliet, Lucien WaldAbstract:The solar radiation impinging at sea surface is an essential variable in climate system. There are several means to assess the daily Irradiation at surface, such as pyranometers aboard ship or on buoys, meteorological re-analyses and satellite-derived Databases. Among the latter, assessments made from the series of geostationary Meteosat satellites offer synoptic views of the tropical and equatorial Atlantic Ocean every 15 min with a spatial resolution of approximately 5 km. Such Meteosat-derived Databases are fairly recent and the quality of the estimates of the daily Irradiation must be established. Efforts have been made for the land masses and must be repeated for the Atlantic Ocean. The Prediction and Research Moored Array in the Tropical Atlantic (PIRATA) network of moorings in the Tropical Atlantic Ocean is considered as a reference for oceanographic Data. It consists in 17 long-term Autonomous Temperature Line Acquisition System (ATLAS) buoys equipped with sensors to measure near-surface meteorological and subsurface oceanic parameters, including downward solar Irradiation. Corrected downward solar daily Irradiation from PIRATA were downloaded from the NOAA web site and were compared to several Databases: CAMS RAD, HelioClim-1, HelioClim-3 v4 and HelioClim-3 v5. CAMS-RAD, the CAMS radiation service, combines products of the Copernicus Atmosphere Monitoring Service (CAMS) on gaseous content and aerosols in the atmosphere together with cloud optical properties deduced every 15 min from Meteosat imagery to supply estimates of the solar Irradiation. Part of this service is the McClear clear sky model that provides estimates of the solar Irradiation that should be observed in cloud-free conditions. The second and third Databases are HelioClim-1 and HelioClim-3 v4 that are derived from Meteosat images using the Heliosat-2 method and the ESRA clear sky model, based on the Linke turbidity factor. HelioClim-3 v5 is the fourth Database and differs from v4 by the partial use of McClear and CAMS products. HelioClim-1 covers the period 1985-2005, while the others start in 2004 and are updated daily. Deviations between PIRATA measurements and estimates were computed and summarized by usual statistics. Biases and root mean square errors differ from one Database to the other. As a whole, the correlation coefficients are large, meaning that each Database reproduces the day-to-day changes in Irradiation well. These good results will support the development of a satellite-derived Database of daily Irradiation created by MINES ParisTech within the HelioClim project. The size of the cells will be 0.25°. HelioClim-1 and HelioClim-3v5 will be combined yielding a period coverage of 32 years, from 1985 to 2016, thus allowing analyses of long term variability of downward shortwave solar radiation over the Atlantic Ocean.
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a web service for controlling the quality of measurements of global solar Irradiation
Solar Energy, 2002Co-Authors: Michael Geiger, Lamissa Diabate, Lionel Menard, Lucien WaldAbstract:The control of the quality of Irradiation Data is often a prerequisite to their further processing. Though Data are usually controlled by meteorological offices, the sources are so numerous that the user often faces time-series of measurements containing questionable values. As customers of Irradiation Data, we established our own procedures to screen time-series of measurements. Since this problem of quality control is of concern to many researchers and engineers and since it is often a lengthy and tedious task, we decided to make this screening procedure available to everyone as a web service. This service is the purpose of this paper. The objective is not to perform a precise and fine control, an objective out of reach without details on the site and instruments, but to perform a likelihood control of the Data and to check their plausibility. This is achieved by comparing observations with some expectations based upon the extraterrestrial Irradiation and a simulation of the Irradiation for clear skies. This service is available to everyone on the Web site www.helioclim.net. It offers a very convenient means to check time-series of Irradiation: Data are input in a HTML page by a copy and paste procedure and the return is also a HTML page that can be analyzed in detail for the Data flagged as suspicious.