It is known for a-Si:H modules that seasonal variations in performance occur because of the effec... more It is known for a-Si:H modules that seasonal variations in performance occur because of the effects of meta-stable degradation mechanisms. These changes in Standard Test Condition (STC) performance are driven by the history of exposure to light and temperature with different time constants and thermal annealing activation energies. The present study provides a link between performance changes following varied indoor
We present a GIS database of solar radiation and photovoltaic (PV) potential estimations of 10 Eu... more We present a GIS database of solar radiation and photovoltaic (PV) potential estimations of 10 European Union Candidate Countries created to support. The database was integrated with a web application to provide access also for a broad public. An application was developed to browse and query GIS maps and to do a simple calculation for any location in the region. The established web site provides access also to analyses and relevant documents (http://iamest.jrc.it/pvgis/pv/index.htm). The European Commission is committed to develop strategies for renewable energy sources for both Member States and Candidate Countries (CC). Under the development of the initiative of the European Research Area, the JRC is responding to this commitment through integrated research and knowledge transfer instruments. The aim of the JRC in this domain is to enhance the integration of European activities (both EU and CC) in the field by creating a critical mass of researchers and establishing a scientific a...
The Matrix and Performance Surface Methods of Energy Rating are related techniques under developm... more The Matrix and Performance Surface Methods of Energy Rating are related techniques under development for the determination of electrical yield that is intended to be a more useful predictor of performance for installers than Wp alone. Here a power matrix or performance surface as a function of irradiance and ambient temperature P(Gi; Ta) is linked to a climatic condition occurrence matrix N(Gi, Ta) for a particular location. The use of just two independent variables has the advantage of simplicity but it is important to evaluate the possible cost of reduced accuracy due to the exclusion of other variable parameters such as Air Mass for example. The power matrix may be determined by outdoor or indoor measurements, and the complete matrix may also be extrapolated from a reduced data set using models of cell behaviour thereby reducing measurement time. The present paper relates solely to crystalline Si and reports on the comparison of outdoor measurements at two sites, and their furthe...
Modelling the fill factor and maximum power point of a solar cell normally results in expressions... more Modelling the fill factor and maximum power point of a solar cell normally results in expressions which require a numerical solution. The development of an energy rating model prompted the need for simple analytical approximations that are valid over a wide range of outdoor conditions. In this paper, new equations are presented which model the fill factor explicitly as a function of irradiance and module temperature, and these equations are tested on outdoor performance data measured at ESTI for a poly-Si and thin-film CdTe module.
Organic photovoltaic (OPV) devices represent a promising technology thanks to the improvements th... more Organic photovoltaic (OPV) devices represent a promising technology thanks to the improvements that have been achieved in recent years, peaking beyond 10% power conversion efficiency (PCE) and to the potentially high throughput and low cost production by using roll-to-roll printing techniques. Besides the improvements in conversion efficiency, it is fundamental to increase their lifetime in order for them to be commercially attractive. In order to study the stability of OPV devices, a round robin was organized in the framework of the SOPHIA project among several European research centres, for the characterization after exposure at different temperature and humidity conditions. While the purpose of the overall activity was to compare the results obtained by different partners, in this work we present an analysis based on the measurements performed at the European Solar Test Installation (ESTI) focusing on the degradation of electrical parameters (Isc, Voc, FF, Pmax) and on series and...
The energy yield of photovoltaic (PV) modules depends not only on the module performance at stand... more The energy yield of photovoltaic (PV) modules depends not only on the module performance at standard test conditions (STC) but rather at a range of operating conditions with varying irradiances and temperatures. Methods for energy yield prediction have been successfully developed for c-Si. However, the determination of energy rating of a PV module is rather complex and therefore not easily applicable in a production environment. Here we examine the possibility to translate the energy rating measured by a reference laboratory on a PV module from a production run to each single module in that production run. It was found that the relative temperature coefficient for the maximum power does not depend on irradiance and is constant for modules from the same production batch. In fact it is nearly constant for c-Si. The irradiance dependence of the PV module performance could be measured within 1 minute, which is sufficiently fast for in-line operation. The energy yield was predicted for t...
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2008
... The three grid datasets are converted to the Lambert az-imuthal equal-area map projection, an... more ... The three grid datasets are converted to the Lambert az-imuthal equal-area map projection, and integrated in the GRASS GIS for spatial es and map processing. For the PVGIS interactive web applications, the following data layers are compiled and optimized for storage needs ...
Estimation of the electrical yield of a PV module is expected to be a more useful predictor of pe... more Estimation of the electrical yield of a PV module is expected to be a more useful predictor of performance for installers than Wp alone. A method for the energy rating of PV modules based on performance surfaces under development at the ESTI laboratory uses the module temperature and incident irradiance as independent variables and has been successful in prediction of
Lecture Notes in Geoinformation and Cartography, 2007
... GIS is extensively used in the PVGIS project, as it offers an environ-ment for: ... Transacti... more ... GIS is extensively used in the PVGIS project, as it offers an environ-ment for: ... Transactions in GIS 8:175-190 úri M, Huld TA, Dunlop ED (2005) PVGIS: a web-based solar radiation database for the calculation of PV potential in Europe. ...
It is known for a-Si:H modules that seasonal variations in performance occur because of the effec... more It is known for a-Si:H modules that seasonal variations in performance occur because of the effects of meta-stable degradation mechanisms. These changes in Standard Test Condition (STC) performance are driven by the history of exposure to light and temperature with different time constants and thermal annealing activation energies. The present study provides a link between performance changes following varied indoor
We present a GIS database of solar radiation and photovoltaic (PV) potential estimations of 10 Eu... more We present a GIS database of solar radiation and photovoltaic (PV) potential estimations of 10 European Union Candidate Countries created to support. The database was integrated with a web application to provide access also for a broad public. An application was developed to browse and query GIS maps and to do a simple calculation for any location in the region. The established web site provides access also to analyses and relevant documents (http://iamest.jrc.it/pvgis/pv/index.htm). The European Commission is committed to develop strategies for renewable energy sources for both Member States and Candidate Countries (CC). Under the development of the initiative of the European Research Area, the JRC is responding to this commitment through integrated research and knowledge transfer instruments. The aim of the JRC in this domain is to enhance the integration of European activities (both EU and CC) in the field by creating a critical mass of researchers and establishing a scientific a...
The Matrix and Performance Surface Methods of Energy Rating are related techniques under developm... more The Matrix and Performance Surface Methods of Energy Rating are related techniques under development for the determination of electrical yield that is intended to be a more useful predictor of performance for installers than Wp alone. Here a power matrix or performance surface as a function of irradiance and ambient temperature P(Gi; Ta) is linked to a climatic condition occurrence matrix N(Gi, Ta) for a particular location. The use of just two independent variables has the advantage of simplicity but it is important to evaluate the possible cost of reduced accuracy due to the exclusion of other variable parameters such as Air Mass for example. The power matrix may be determined by outdoor or indoor measurements, and the complete matrix may also be extrapolated from a reduced data set using models of cell behaviour thereby reducing measurement time. The present paper relates solely to crystalline Si and reports on the comparison of outdoor measurements at two sites, and their furthe...
Modelling the fill factor and maximum power point of a solar cell normally results in expressions... more Modelling the fill factor and maximum power point of a solar cell normally results in expressions which require a numerical solution. The development of an energy rating model prompted the need for simple analytical approximations that are valid over a wide range of outdoor conditions. In this paper, new equations are presented which model the fill factor explicitly as a function of irradiance and module temperature, and these equations are tested on outdoor performance data measured at ESTI for a poly-Si and thin-film CdTe module.
Organic photovoltaic (OPV) devices represent a promising technology thanks to the improvements th... more Organic photovoltaic (OPV) devices represent a promising technology thanks to the improvements that have been achieved in recent years, peaking beyond 10% power conversion efficiency (PCE) and to the potentially high throughput and low cost production by using roll-to-roll printing techniques. Besides the improvements in conversion efficiency, it is fundamental to increase their lifetime in order for them to be commercially attractive. In order to study the stability of OPV devices, a round robin was organized in the framework of the SOPHIA project among several European research centres, for the characterization after exposure at different temperature and humidity conditions. While the purpose of the overall activity was to compare the results obtained by different partners, in this work we present an analysis based on the measurements performed at the European Solar Test Installation (ESTI) focusing on the degradation of electrical parameters (Isc, Voc, FF, Pmax) and on series and...
The energy yield of photovoltaic (PV) modules depends not only on the module performance at stand... more The energy yield of photovoltaic (PV) modules depends not only on the module performance at standard test conditions (STC) but rather at a range of operating conditions with varying irradiances and temperatures. Methods for energy yield prediction have been successfully developed for c-Si. However, the determination of energy rating of a PV module is rather complex and therefore not easily applicable in a production environment. Here we examine the possibility to translate the energy rating measured by a reference laboratory on a PV module from a production run to each single module in that production run. It was found that the relative temperature coefficient for the maximum power does not depend on irradiance and is constant for modules from the same production batch. In fact it is nearly constant for c-Si. The irradiance dependence of the PV module performance could be measured within 1 minute, which is sufficiently fast for in-line operation. The energy yield was predicted for t...
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2008
... The three grid datasets are converted to the Lambert az-imuthal equal-area map projection, an... more ... The three grid datasets are converted to the Lambert az-imuthal equal-area map projection, and integrated in the GRASS GIS for spatial es and map processing. For the PVGIS interactive web applications, the following data layers are compiled and optimized for storage needs ...
Estimation of the electrical yield of a PV module is expected to be a more useful predictor of pe... more Estimation of the electrical yield of a PV module is expected to be a more useful predictor of performance for installers than Wp alone. A method for the energy rating of PV modules based on performance surfaces under development at the ESTI laboratory uses the module temperature and incident irradiance as independent variables and has been successful in prediction of
Lecture Notes in Geoinformation and Cartography, 2007
... GIS is extensively used in the PVGIS project, as it offers an environ-ment for: ... Transacti... more ... GIS is extensively used in the PVGIS project, as it offers an environ-ment for: ... Transactions in GIS 8:175-190 úri M, Huld TA, Dunlop ED (2005) PVGIS: a web-based solar radiation database for the calculation of PV potential in Europe. ...
Uploads
Papers by Ewan Dunlop