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Papers by laurent linguet

Energies, Sep 26, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Международный научный журнал Альтернативная энергетика и экология, 2008

This study was conducted in French Guiana, a region characterized by specific human and environme... more This study was conducted in French Guiana, a region characterized by specific human and environmental conditions, by members of the University of the French Antilles and French Guiana’s Research Group on Renewable Energies (GRER) in collaboration with the regional office of ADEME (Agency for the Environment and Energy Management) and the companies that installed the photovoltaic systems. Its aim was a better understanding of the attitudes, expectations, and relationship of the users towards the photovoltaic installations. The data collected made it possible to make suggestions for adapting the photovoltaic systems to their environment by taking into account social, cultural, and geoclimatic specificities. Analysis of on-site productivity provides valuable information on energy profiles and types of use. Field surveys made it possible to associate users’ perception of the energy production equipment and their degree of satisfaction with operating efficiency and on-site maintenance. This aspect is essential for analyzing the actual rate of use of the energy that is theoretically available. Parallel to these surveys, the results of the study carried out on the performance of the photovoltaic systems made it possible to learn the quantitative aspects of the energy produced and consumed as well as the qualitative aspects of the parameters that condition the performance of the photovoltaic systems. After keyboarding, the subjective, qualitative as well as the quantitative variables were processed using a statistical analysis program in order to determine the correlations between them and to prepare the final conclusions. These surveys and measurements were carried out simultaneously over the 2004-2005 period.

HAL (Le Centre pour la Communication Scientifique Directe), May 5, 2021

Energy transition requires a holistic approach, involving land, resources, environmental and econ... more Energy transition requires a holistic approach, involving land, resources, environmental and economical data and constraints. The core purpose of energy transition, is to migrate power systems towards renewable energy usage (solar, hydro, biomass, wind), in a technical and economical viable manner. In this article we address this challenge as a spatio-temporal analysis problem combined with decision support targeted for policy makers and investors. We show how the selection of potential PV sites, can efficiently be combined with the optimization of the connection to the grid in terms of operational costs. Our contribution lies in bringing forward a modeling analogy with the SONET problem, addressed in fiber network designs. Improved results compared to an existing GIS-optimization PV site placement approach are illustrated on a real case study and data from the French Guiana. RÉSUMÉ. La transition énergétique nécessite une approche holistique, impliquant la gestion des sols, ressources potentielles, les données et contraintes environnementales et économiques. L'objectif central est de migrer les systèmes électriques vers l'utilisation des énergies renouvelables (solaire, hydroélectrique, biomasse, éolienne), de manière techniquement et économiquement viable. Dans cet article, nous abordons ce défi comme un problème d'analyse spatio-temporelle intégré à un modèle d'aide à la décision conçu pour les décideurs politiques et les investisseurs. Nous montrons comment la recherche de sites photovoltaïques peut être combinée efficacement avec l'optimisation du raccordement au réseau en termes de coûts. Notre contribution réside dans la mise en place d'une analogie de modélisation avec le problème SONET, défini dans les conceptions de réseaux de fibre optique. La qualité des résultats comparés à une approche existante de placement de parcs photovoltaïques est présentée sur un cas d'étude en Guyane française.

Международный научный журнал Альтернативная энергетика и экология, 2008

This study was conducted in French Guiana, a region characterized by specific human and environme... more This study was conducted in French Guiana, a region characterized by specific human and environmental conditions, by members of the University of the French Antilles and French Guiana’s Research Group on Renewable Energies (GRER) in collaboration with the regional office of ADEME (Agency for the Environment and Energy Management) and the companies that installed the photovoltaic systems. Its aim was a better understanding of the attitudes, expectations, and relationship of the users towards the photovoltaic installations. The data collected made it possible to make suggestions for adapting the photovoltaic systems to their environment by taking into account social, cultural, and geoclimatic specificities. Analysis of on-site productivity provides valuable information on energy profiles and types of use. Field surveys made it possible to associate users’ perception of the energy production equipment and their degree of satisfaction with operating efficiency and on-site maintenance. This aspect is essential for analyzing the actual rate of use of the energy that is theoretically available. Parallel to these surveys, the results of the study carried out on the performance of the photovoltaic systems made it possible to learn the quantitative aspects of the energy produced and consumed as well as the qualitative aspects of the parameters that condition the performance of the photovoltaic systems. After keyboarding, the subjective, qualitative as well as the quantitative variables were processed using a statistical analysis program in order to determine the correlations between them and to prepare the final conclusions. These surveys and measurements were carried out simultaneously over the 2004-2005 period.

HAL (Le Centre pour la Communication Scientifique Directe), Dec 1, 2020

IEEE Sensors Journal, Jun 15, 2022

This paper presents a new paradigm in the analysis and methodology for Surface Acoustic Wave (SAW... more This paper presents a new paradigm in the analysis and methodology for Surface Acoustic Wave (SAW) devices for sensing application in a liquid medium. Th new protocol encourages the analysis of the electrical and electro-acoustic behavior of the sensor rather than limiting the measurement interest to mechanical interactions between the sensor and the medium. According to experimental responses, some hypotheses are proposed allowing the separation of each electrical and mechanical mechanisms based on post-treatment analysis methods. Thus, to better understand the proposed approach, we introduced a new and unconventional energy flow chart of the acoustic wave propagation in the SAW device which helped us extracting our hypotheses. This new paradigm allows us to get information related to both dielectric and mechanical parameters of a liquid sample using a single sensor, enriching the response. In contrary to most works surrounding the SAW sensors, this new method does not intend to increase the sensitivity of the sensors. Instead, it focuses on an unconventional ”holistic” approach that achieves an improved understanding of the sensitive phenomena and enriches the global response and analysis to a given characterization. Ultimately, this improved understanding could help to increase the sensitivity to a selected target using the same method. This approach could be used with all electro-acoustic sensor devices. We applied this method to Love wave sensors with different technological characteristics influencing the electric and acoustic response with numerous fluid solutions for a large diversity of dielectric constants and mechanical characteristics responses. A larger set of measurement from the Love wave sensor is obtained allowing to extract both dielectric and mechanical parameters of a liquid medium on the Love wave sensor surface.

HAL (Le Centre pour la Communication Scientifique Directe), Dec 1, 2020

HAL (Le Centre pour la Communication Scientifique Directe), 2022

HAL (Le Centre pour la Communication Scientifique Directe), 2022

Biogeosciences, Jan 24, 2017

Natural disturbances are the dominant form of forest regeneration and dynamics in unmanaged tropi... more Natural disturbances are the dominant form of forest regeneration and dynamics in unmanaged tropical forests. Monitoring the size distribution of treefall gaps is important to better understand and predict the carbon budget in response to land use and other global changes. In this study, we model the size frequency distribution of natural canopy gaps with a discrete power law distribution. We use a Bayesian framework to introduce and test, using Monte Carlo Markov chain and Kuo-Mallick algorithms, the effect of local physical environment on gap size distribution. We apply our methodological framework to an original light detecting and ranging dataset in which natural forest gaps were delineated over 30 000 ha of unmanaged forest. We highlight strong links between gap size distribution and environment, primarily hydrological conditions and topography, with large gaps being more frequent on floodplains and in wind-exposed areas. In the future, we plan to apply our methodological framework on a larger scale using satellite data. Additionally, although gap size distribution variation is clearly under environmental control, variation in gap size distribution in time should be tested against climate variability.

HAL (Le Centre pour la Communication Scientifique Directe), Nov 16, 2022

French Guiana heavily relies on high-cost imported materials to sustain its strong population gro... more French Guiana heavily relies on high-cost imported materials to sustain its strong population growth and construction demand. Local alternatives such as earth concrete are needed to reduce the use of conventional concrete. It is currently unknown if tropical soils are suitable for non-cement stabilized earth construction and especially what are the characteristics of these soils. In this study, 14 soils were characterized (particle size, EDS-SEM, FTIR, color) and evaluated as building materials on earth mortar prismatic specimens. For each soil, physical and mechanical mortar properties were evaluated based on two formulations of equivalent plastic consistency, with or without dispersant (0.5% of dry mass). The results show that hardened mortar properties were driven by water content at fresh state, particle size, and Fe and Al-oxide content. Water content directly correlated with fine-grains content and negatively impacted all mortar properties. The use of dispersant reduced water content and considerably improved compressive strengths, reaching up to 4 MPa. Compressive strength positively correlated with Fe and Al content and could be predicted by soil color. Overall, the characterized soils demonstrated good mechanical aptitude when mixed with a low level of dispersant, indicating a high potential for construction, particularly for metal oxide-rich soils.

This study was conducted in French Guiana, a region characterized by specific human and environme... more This study was conducted in French Guiana, a region characterized by specific human and environmental conditions, by members of the University of the French Antilles and French Guiana’s Research Group on Renewable Energies (GRER) in collaboration with the regional office of ADEME (Agency for the Environment and Energy Management) and the companies that installed the photovoltaic systems. Its aim was a better understanding of the attitudes, expectations, and relationship of the users towards the photovoltaic installations. The data collected made it possible to make suggestions for adapting the photovoltaic systems to their environment by taking into account social, cultural, and geoclimatic specificities. Analysis of on-site productivity provides valuable information on energy profiles and types of use. Field surveys made it possible to associate users’ perception of the energy production equipment and their degree of satisfaction with operating efficiency and on-site maintenance. T...

Despite the global importance of the Congo Basin, which is the second largest river basin in the ... more Despite the global importance of the Congo Basin, which is the second largest river basin in the world, the limited understanding of its hydro-climatic patterns is in part due to the lack of in-situ monitoring of climate variables there. Climate and hydrological station networks are sparse and poorly maintained; the few networks that were implemented during the colonial period have shrunk considerably. Conversely, the recent improvements in remote sensing technology provide more observations than ever before that can advance hydrological studies, particularly in tropical basins. This work provides the first monitoring of water level at the basin scale for the Congo Basin based on merged data from different altimetry missions: ENVISAT, Jason-2 and SARAL. More than 500 time series of water level are computed for a twenty of contributors, over the period of 2002 to 2010 for 200 ENVISAT series, including using the second orbital period, from 2008 for 75 Jason-2 series and from mid 2013 ...

Solar Energy, 2018

The purpose of this study was to improve global horizontal irradiation (GHI) estimates under clou... more The purpose of this study was to improve global horizontal irradiation (GHI) estimates under cloudy sky conditions using the Heliosat-2 method (Rigollier et al., 2004) calibrated with Geostationary Operational Environmental Satellite images (GOES) (Albarelo et al., 2015). The Heliosat-2 method using GOES images as input (GOES_H2) was coupled with a cloudy sky radiative transfer parameterisation (RTP) (RTP: radiative transfer parameterisation) to better account for local cloud properties. The key element of this parameterisation is the cloud absorption coefficient, which was the only element to be computed. The GHI estimates obtained when using GOES_H2 coupled with a RTP (RTP_H2) were compared against GHI measurements from six meteorological stations in French Guiana over four years. We used root mean square error (RMSE), mean bias error (MBE), correlation coefficient, and the Kolmogorov Smirnov test integral to assess GHI estimates accuracy. RTP_H2 obtained estimates were also compared with GOES_H2 estimates. Our results show an improvement in the GHI estimates under cloudy, clear, and all sky conditions. Under cloudy skies, the RMSE and MBE of our method RTP_H2 ranged from 43% to 63% and −2% to −22%, respectively, whereas those of GOES_H2 method ranged from 66% to 87% and −48% to −65%, respectively. Another effect of the new method was the improvement in clear sky GHI estimates: the RMSE and MBE ranged from 16% to 24% and −20% to −8%, respectively, while those of GOES_H2 ranged from 19% to 28% and −23% to −10%, respectively. The improvement in GHI estimates under cloudy sky conditions led to better GHI estimates under all sky conditions: the RMSE and MBE of RTP_H2 ranged from 19% to 26% and −7% to −2%, respectively, while the corresponding values for GOES_H2 ranged from 22% to 32% and −15% to −8%, respectively. The suggested cloudy sky RTP offers the advantages of simple implementation and good computation speed. This method requires only one parameter; users need to configure a cloud absorption coefficient suitable for their local conditions. We conclude that coupling the Heliosat-2 method with a cloudy sky RTP improves GHI estimates in French Guiana and reduces discrepancies between satellite-derived irradiation and ground measurements in areas with high cloudiness.

Renewable Energy, Oct 1, 2017

The purpose of this article is to evaluate the potential for solar energy in the Guiana Shield an... more The purpose of this article is to evaluate the potential for solar energy in the Guiana Shield and propose indicators to encourage the exploitation of solar energy systems in this area. For this, we use the Heliosat-2 optimized method to process images from the geostationary meteorological satellite GOES acquired in the period from April 2010 to July 2015. We calculated the average daily global horizontal irradiation (GHI) and direct normal irradiation (DNI) throughout the study period. The results obtained allowed us to establish four indicators: maps of production potential, the inter-day variability of DNI and GHI, maps of solar panel orientation related to maximum solar potential, and maps of areas where the solar resource is under the exploitable potential threshold. We also added an additional indicator, the suitability of areas for solar system installation depending on the ground slope. Our study shows that the average value of production potential for the entire Guiana Shield is approximately 1780 kWh.kWc-1 .year-1 for GHI and 2040 kWh.kWc-1 .year-1 for DNI. Comparisons with pyranometer measurements indicate an error relative bias of less than 2 % and a relative RMSE of less than 21 % for hourly estimates of GHI. Although the Guiana Shield region is covered by many clouds, few areas show insufficient solar potential for the exploitation of GHI and DNI, but the hilly nature of the area limits possible locations of very large power plants and instead favors more medium-sized plants. This is the first study that offers exploitability indicators for solar resources in the Guiana Shield. In conclusion, the established indicators provide a new perspective on the solar potential in the Guiana Shield and are expected to promote the development of new solar energy operating systems.

AGU Fall Meeting Abstracts, Dec 1, 2011

2022 13th International Renewable Energy Congress (IREC)

ITISE 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Troisièmes Journées Francophones de Programmation par Contraintes (JFPC07), Jun 4, 2007

2006 First International Symposium on Environment Identities and Mediterranean Area, 2006

We analyze the efficiency of solar heaters, and how usual existing ones operate in a range corres... more We analyze the efficiency of solar heaters, and how usual existing ones operate in a range corresponding to an important loss of efficiency between clear weather and covered weather operation. This gives its interest to a simple solution to avoid a "threshold effect" pointed out in our analysis of standard heater operation. In short, this consists in warming, in the solar collector, the cold water input instead of cycling the water at the balloon temperature. This results in a significant reduction of the collector average temperature, which explains the corresponding thermal losses reduction.

Energies, Sep 26, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Международный научный журнал Альтернативная энергетика и экология, 2008

This study was conducted in French Guiana, a region characterized by specific human and environme... more This study was conducted in French Guiana, a region characterized by specific human and environmental conditions, by members of the University of the French Antilles and French Guiana’s Research Group on Renewable Energies (GRER) in collaboration with the regional office of ADEME (Agency for the Environment and Energy Management) and the companies that installed the photovoltaic systems. Its aim was a better understanding of the attitudes, expectations, and relationship of the users towards the photovoltaic installations. The data collected made it possible to make suggestions for adapting the photovoltaic systems to their environment by taking into account social, cultural, and geoclimatic specificities. Analysis of on-site productivity provides valuable information on energy profiles and types of use. Field surveys made it possible to associate users’ perception of the energy production equipment and their degree of satisfaction with operating efficiency and on-site maintenance. This aspect is essential for analyzing the actual rate of use of the energy that is theoretically available. Parallel to these surveys, the results of the study carried out on the performance of the photovoltaic systems made it possible to learn the quantitative aspects of the energy produced and consumed as well as the qualitative aspects of the parameters that condition the performance of the photovoltaic systems. After keyboarding, the subjective, qualitative as well as the quantitative variables were processed using a statistical analysis program in order to determine the correlations between them and to prepare the final conclusions. These surveys and measurements were carried out simultaneously over the 2004-2005 period.

HAL (Le Centre pour la Communication Scientifique Directe), May 5, 2021

Energy transition requires a holistic approach, involving land, resources, environmental and econ... more Energy transition requires a holistic approach, involving land, resources, environmental and economical data and constraints. The core purpose of energy transition, is to migrate power systems towards renewable energy usage (solar, hydro, biomass, wind), in a technical and economical viable manner. In this article we address this challenge as a spatio-temporal analysis problem combined with decision support targeted for policy makers and investors. We show how the selection of potential PV sites, can efficiently be combined with the optimization of the connection to the grid in terms of operational costs. Our contribution lies in bringing forward a modeling analogy with the SONET problem, addressed in fiber network designs. Improved results compared to an existing GIS-optimization PV site placement approach are illustrated on a real case study and data from the French Guiana. RÉSUMÉ. La transition énergétique nécessite une approche holistique, impliquant la gestion des sols, ressources potentielles, les données et contraintes environnementales et économiques. L'objectif central est de migrer les systèmes électriques vers l'utilisation des énergies renouvelables (solaire, hydroélectrique, biomasse, éolienne), de manière techniquement et économiquement viable. Dans cet article, nous abordons ce défi comme un problème d'analyse spatio-temporelle intégré à un modèle d'aide à la décision conçu pour les décideurs politiques et les investisseurs. Nous montrons comment la recherche de sites photovoltaïques peut être combinée efficacement avec l'optimisation du raccordement au réseau en termes de coûts. Notre contribution réside dans la mise en place d'une analogie de modélisation avec le problème SONET, défini dans les conceptions de réseaux de fibre optique. La qualité des résultats comparés à une approche existante de placement de parcs photovoltaïques est présentée sur un cas d'étude en Guyane française.

Международный научный журнал Альтернативная энергетика и экология, 2008

This study was conducted in French Guiana, a region characterized by specific human and environme... more This study was conducted in French Guiana, a region characterized by specific human and environmental conditions, by members of the University of the French Antilles and French Guiana’s Research Group on Renewable Energies (GRER) in collaboration with the regional office of ADEME (Agency for the Environment and Energy Management) and the companies that installed the photovoltaic systems. Its aim was a better understanding of the attitudes, expectations, and relationship of the users towards the photovoltaic installations. The data collected made it possible to make suggestions for adapting the photovoltaic systems to their environment by taking into account social, cultural, and geoclimatic specificities. Analysis of on-site productivity provides valuable information on energy profiles and types of use. Field surveys made it possible to associate users’ perception of the energy production equipment and their degree of satisfaction with operating efficiency and on-site maintenance. This aspect is essential for analyzing the actual rate of use of the energy that is theoretically available. Parallel to these surveys, the results of the study carried out on the performance of the photovoltaic systems made it possible to learn the quantitative aspects of the energy produced and consumed as well as the qualitative aspects of the parameters that condition the performance of the photovoltaic systems. After keyboarding, the subjective, qualitative as well as the quantitative variables were processed using a statistical analysis program in order to determine the correlations between them and to prepare the final conclusions. These surveys and measurements were carried out simultaneously over the 2004-2005 period.

HAL (Le Centre pour la Communication Scientifique Directe), Dec 1, 2020

IEEE Sensors Journal, Jun 15, 2022

This paper presents a new paradigm in the analysis and methodology for Surface Acoustic Wave (SAW... more This paper presents a new paradigm in the analysis and methodology for Surface Acoustic Wave (SAW) devices for sensing application in a liquid medium. Th new protocol encourages the analysis of the electrical and electro-acoustic behavior of the sensor rather than limiting the measurement interest to mechanical interactions between the sensor and the medium. According to experimental responses, some hypotheses are proposed allowing the separation of each electrical and mechanical mechanisms based on post-treatment analysis methods. Thus, to better understand the proposed approach, we introduced a new and unconventional energy flow chart of the acoustic wave propagation in the SAW device which helped us extracting our hypotheses. This new paradigm allows us to get information related to both dielectric and mechanical parameters of a liquid sample using a single sensor, enriching the response. In contrary to most works surrounding the SAW sensors, this new method does not intend to increase the sensitivity of the sensors. Instead, it focuses on an unconventional ”holistic” approach that achieves an improved understanding of the sensitive phenomena and enriches the global response and analysis to a given characterization. Ultimately, this improved understanding could help to increase the sensitivity to a selected target using the same method. This approach could be used with all electro-acoustic sensor devices. We applied this method to Love wave sensors with different technological characteristics influencing the electric and acoustic response with numerous fluid solutions for a large diversity of dielectric constants and mechanical characteristics responses. A larger set of measurement from the Love wave sensor is obtained allowing to extract both dielectric and mechanical parameters of a liquid medium on the Love wave sensor surface.

HAL (Le Centre pour la Communication Scientifique Directe), Dec 1, 2020

HAL (Le Centre pour la Communication Scientifique Directe), 2022

HAL (Le Centre pour la Communication Scientifique Directe), 2022

Biogeosciences, Jan 24, 2017

Natural disturbances are the dominant form of forest regeneration and dynamics in unmanaged tropi... more Natural disturbances are the dominant form of forest regeneration and dynamics in unmanaged tropical forests. Monitoring the size distribution of treefall gaps is important to better understand and predict the carbon budget in response to land use and other global changes. In this study, we model the size frequency distribution of natural canopy gaps with a discrete power law distribution. We use a Bayesian framework to introduce and test, using Monte Carlo Markov chain and Kuo-Mallick algorithms, the effect of local physical environment on gap size distribution. We apply our methodological framework to an original light detecting and ranging dataset in which natural forest gaps were delineated over 30 000 ha of unmanaged forest. We highlight strong links between gap size distribution and environment, primarily hydrological conditions and topography, with large gaps being more frequent on floodplains and in wind-exposed areas. In the future, we plan to apply our methodological framework on a larger scale using satellite data. Additionally, although gap size distribution variation is clearly under environmental control, variation in gap size distribution in time should be tested against climate variability.

HAL (Le Centre pour la Communication Scientifique Directe), Nov 16, 2022

French Guiana heavily relies on high-cost imported materials to sustain its strong population gro... more French Guiana heavily relies on high-cost imported materials to sustain its strong population growth and construction demand. Local alternatives such as earth concrete are needed to reduce the use of conventional concrete. It is currently unknown if tropical soils are suitable for non-cement stabilized earth construction and especially what are the characteristics of these soils. In this study, 14 soils were characterized (particle size, EDS-SEM, FTIR, color) and evaluated as building materials on earth mortar prismatic specimens. For each soil, physical and mechanical mortar properties were evaluated based on two formulations of equivalent plastic consistency, with or without dispersant (0.5% of dry mass). The results show that hardened mortar properties were driven by water content at fresh state, particle size, and Fe and Al-oxide content. Water content directly correlated with fine-grains content and negatively impacted all mortar properties. The use of dispersant reduced water content and considerably improved compressive strengths, reaching up to 4 MPa. Compressive strength positively correlated with Fe and Al content and could be predicted by soil color. Overall, the characterized soils demonstrated good mechanical aptitude when mixed with a low level of dispersant, indicating a high potential for construction, particularly for metal oxide-rich soils.

This study was conducted in French Guiana, a region characterized by specific human and environme... more This study was conducted in French Guiana, a region characterized by specific human and environmental conditions, by members of the University of the French Antilles and French Guiana’s Research Group on Renewable Energies (GRER) in collaboration with the regional office of ADEME (Agency for the Environment and Energy Management) and the companies that installed the photovoltaic systems. Its aim was a better understanding of the attitudes, expectations, and relationship of the users towards the photovoltaic installations. The data collected made it possible to make suggestions for adapting the photovoltaic systems to their environment by taking into account social, cultural, and geoclimatic specificities. Analysis of on-site productivity provides valuable information on energy profiles and types of use. Field surveys made it possible to associate users’ perception of the energy production equipment and their degree of satisfaction with operating efficiency and on-site maintenance. T...

Despite the global importance of the Congo Basin, which is the second largest river basin in the ... more Despite the global importance of the Congo Basin, which is the second largest river basin in the world, the limited understanding of its hydro-climatic patterns is in part due to the lack of in-situ monitoring of climate variables there. Climate and hydrological station networks are sparse and poorly maintained; the few networks that were implemented during the colonial period have shrunk considerably. Conversely, the recent improvements in remote sensing technology provide more observations than ever before that can advance hydrological studies, particularly in tropical basins. This work provides the first monitoring of water level at the basin scale for the Congo Basin based on merged data from different altimetry missions: ENVISAT, Jason-2 and SARAL. More than 500 time series of water level are computed for a twenty of contributors, over the period of 2002 to 2010 for 200 ENVISAT series, including using the second orbital period, from 2008 for 75 Jason-2 series and from mid 2013 ...

Solar Energy, 2018

The purpose of this study was to improve global horizontal irradiation (GHI) estimates under clou... more The purpose of this study was to improve global horizontal irradiation (GHI) estimates under cloudy sky conditions using the Heliosat-2 method (Rigollier et al., 2004) calibrated with Geostationary Operational Environmental Satellite images (GOES) (Albarelo et al., 2015). The Heliosat-2 method using GOES images as input (GOES_H2) was coupled with a cloudy sky radiative transfer parameterisation (RTP) (RTP: radiative transfer parameterisation) to better account for local cloud properties. The key element of this parameterisation is the cloud absorption coefficient, which was the only element to be computed. The GHI estimates obtained when using GOES_H2 coupled with a RTP (RTP_H2) were compared against GHI measurements from six meteorological stations in French Guiana over four years. We used root mean square error (RMSE), mean bias error (MBE), correlation coefficient, and the Kolmogorov Smirnov test integral to assess GHI estimates accuracy. RTP_H2 obtained estimates were also compared with GOES_H2 estimates. Our results show an improvement in the GHI estimates under cloudy, clear, and all sky conditions. Under cloudy skies, the RMSE and MBE of our method RTP_H2 ranged from 43% to 63% and −2% to −22%, respectively, whereas those of GOES_H2 method ranged from 66% to 87% and −48% to −65%, respectively. Another effect of the new method was the improvement in clear sky GHI estimates: the RMSE and MBE ranged from 16% to 24% and −20% to −8%, respectively, while those of GOES_H2 ranged from 19% to 28% and −23% to −10%, respectively. The improvement in GHI estimates under cloudy sky conditions led to better GHI estimates under all sky conditions: the RMSE and MBE of RTP_H2 ranged from 19% to 26% and −7% to −2%, respectively, while the corresponding values for GOES_H2 ranged from 22% to 32% and −15% to −8%, respectively. The suggested cloudy sky RTP offers the advantages of simple implementation and good computation speed. This method requires only one parameter; users need to configure a cloud absorption coefficient suitable for their local conditions. We conclude that coupling the Heliosat-2 method with a cloudy sky RTP improves GHI estimates in French Guiana and reduces discrepancies between satellite-derived irradiation and ground measurements in areas with high cloudiness.

Renewable Energy, Oct 1, 2017

The purpose of this article is to evaluate the potential for solar energy in the Guiana Shield an... more The purpose of this article is to evaluate the potential for solar energy in the Guiana Shield and propose indicators to encourage the exploitation of solar energy systems in this area. For this, we use the Heliosat-2 optimized method to process images from the geostationary meteorological satellite GOES acquired in the period from April 2010 to July 2015. We calculated the average daily global horizontal irradiation (GHI) and direct normal irradiation (DNI) throughout the study period. The results obtained allowed us to establish four indicators: maps of production potential, the inter-day variability of DNI and GHI, maps of solar panel orientation related to maximum solar potential, and maps of areas where the solar resource is under the exploitable potential threshold. We also added an additional indicator, the suitability of areas for solar system installation depending on the ground slope. Our study shows that the average value of production potential for the entire Guiana Shield is approximately 1780 kWh.kWc-1 .year-1 for GHI and 2040 kWh.kWc-1 .year-1 for DNI. Comparisons with pyranometer measurements indicate an error relative bias of less than 2 % and a relative RMSE of less than 21 % for hourly estimates of GHI. Although the Guiana Shield region is covered by many clouds, few areas show insufficient solar potential for the exploitation of GHI and DNI, but the hilly nature of the area limits possible locations of very large power plants and instead favors more medium-sized plants. This is the first study that offers exploitability indicators for solar resources in the Guiana Shield. In conclusion, the established indicators provide a new perspective on the solar potential in the Guiana Shield and are expected to promote the development of new solar energy operating systems.

AGU Fall Meeting Abstracts, Dec 1, 2011

2022 13th International Renewable Energy Congress (IREC)

ITISE 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Troisièmes Journées Francophones de Programmation par Contraintes (JFPC07), Jun 4, 2007

2006 First International Symposium on Environment Identities and Mediterranean Area, 2006

We analyze the efficiency of solar heaters, and how usual existing ones operate in a range corres... more We analyze the efficiency of solar heaters, and how usual existing ones operate in a range corresponding to an important loss of efficiency between clear weather and covered weather operation. This gives its interest to a simple solution to avoid a "threshold effect" pointed out in our analysis of standard heater operation. In short, this consists in warming, in the solar collector, the cold water input instead of cycling the water at the balloon temperature. This results in a significant reduction of the collector average temperature, which explains the corresponding thermal losses reduction.