29 research outputs found
3D simulation of complex shading affecting PV systems taking benefit from the power of graphics cards developed for the video game industry
Shading reduces the power output of a photovoltaic (PV) system. The design
engineering of PV systems requires modeling and evaluating shading losses. Some
PV systems are affected by complex shading scenes whose resulting PV energy
losses are very difficult to evaluate with current modeling tools. Several
specialized PV design and simulation software include the possibility to
evaluate shading losses. They generally possess a Graphical User Interface
(GUI) through which the user can draw a 3D shading scene, and then evaluate its
corresponding PV energy losses. The complexity of the objects that these tools
can handle is relatively limited. We have created a software solution, 3DPV,
which allows evaluating the energy losses induced by complex 3D scenes on PV
generators. The 3D objects can be imported from specialized 3D modeling
software or from a 3D object library. The shadows cast by this 3D scene on the
PV generator are then directly evaluated from the Graphics Processing Unit
(GPU). Thanks to the recent development of GPUs for the video game industry,
the shadows can be evaluated with a very high spatial resolution that reaches
well beyond the PV cell level, in very short calculation times. A PV simulation
model then translates the geometrical shading into PV energy output losses.
3DPV has been implemented using WebGL, which allows it to run directly from a
Web browser, without requiring any local installation from the user. This also
allows taken full benefits from the information already available from
Internet, such as the 3D object libraries. This contribution describes, step by
step, the method that allows 3DPV to evaluate the PV energy losses caused by
complex shading. We then illustrate the results of this methodology to several
application cases that are encountered in the world of PV systems design.Comment: 5 page, 9 figures, conference proceedings, 29th European Photovoltaic
Solar Energy Conference and Exhibition, Amsterdam, 201
A free real-time hourly tilted solar irradiation data Website for Europe
The engineering of solar power applications, such as photovoltaic energy (PV)
or thermal solar energy requires the knowledge of the solar resource available
for the solar energy system. This solar resource is generally obtained from
datasets, and is either measured by ground-stations, through the use of
pyranometers, or by satellites. The solar irradiation data are generally not
free, and their cost can be high, in particular if high temporal resolution is
required, such as hourly data. In this work, we present an alternative method
to provide free hourly global solar tilted irradiation data for the whole
European territory through a web platform. The method that we have developed
generates solar irradiation data from a combination of clear-sky simulations
and weather conditions data. The results are publicly available for free
through Soweda, a Web interface. To our knowledge, this is the first time that
hourly solar irradiance data are made available online, in real-time, and for
free, to the public. The accuracy of these data is not suitable for
applications that require high data accuracy, but can be very useful for other
applications that only require a rough estimate of solar irradiation.Comment: 3 pages, 2 figures, conference proceedings, 29th European
Photovoltaic Solar Energy Conference and Exhibition, 2014, Amsterda
Automatic fault detection on BIPV systems without solar irradiation data
BIPV systems are small PV generation units spread out over the territory, and
whose characteristics are very diverse. This makes difficult a cost-effective
procedure for monitoring, fault detection, performance analyses, operation and
maintenance. As a result, many problems affecting BIPV systems go undetected.
In order to carry out effective automatic fault detection procedures, we need a
performance indicator that is reliable and that can be applied on many PV
systems at a very low cost. The existing approaches for analyzing the
performance of PV systems are often based on the Performance Ratio (PR), whose
accuracy depends on good solar irradiation data, which in turn can be very
difficult to obtain or cost-prohibitive for the BIPV owner. We present an
alternative fault detection procedure based on a performance indicator that can
be constructed on the sole basis of the energy production data measured at the
BIPV systems. This procedure does not require the input of operating conditions
data, such as solar irradiation, air temperature, or wind speed. The
performance indicator, called Performance to Peers (P2P), is constructed from
spatial and temporal correlations between the energy output of neighboring and
similar PV systems. This method was developed from the analysis of the energy
production data of approximately 10,000 BIPV systems located in Europe. The
results of our procedure are illustrated on the hourly, daily and monthly data
monitored during one year at one BIPV system located in the South of Belgium.
Our results confirm that it is possible to carry out automatic fault detection
procedures without solar irradiation data. P2P proves to be more stable than PR
most of the time, and thus constitutes a more reliable performance indicator
for fault detection procedures.Comment: 7 pages, 8 figures, conference proceedings, 29th European
Photovoltaic Solar Energy Conference and Exhibition, Amsterdam, 201
Performance Analysis of 10,000 Residential PV Systems in France and Belgium
The main objective of this paper is to review the state of the art of residential PV systems in France and Belgium. This is done analyzing the operational data of 10650 PV systems (9657 located in France and 993 in Belgium). Three main questions are posed. How much energy do they produce? What level of performance is associated to their production? Which are the key parameters that most influence their quality? During the year 2010, the PV systems in France have produced a mean annual energy of 1163 kWh/kWp in France and 852 kWh/kWp in Belgium. As a whole, the orientation of PV generators causes energy productions to be some 7% inferior to optimally oriented PV systems. The mean Performance Ratio is 76% in France and 78% in Belgium, and the mean Performance Index is 85% in both countries. On average, the real power of the PV modules falls 4.9% below its corresponding nominal power announced on the manufacturer?s datasheet. A brief analysis by PV modules technology has lead to relevant observations about two technologies in particular. On the one hand, the PV systems equipped with Heterojunction with Intrinsic. Thin layer (HIT) modules show performances higher than average. On the other hand, the systems equipped with Copper Indium (di)Selenide (CIS) modules show a real power that is 16 % lower than their nominal value
Detección automática de fallos de operación en instalaciones fotovoltaicas domésticas
El objetivo principal de este trabajo es implementar una herramienta de análisis automático de datos de operación para detectar fallos en instalaciones fotovoltaicas domésticas que disponen de sistemas de monitorización. Para ello se han analizado los datos de productividad de 10.650 sistemas fotovoltaicos (9657 situados en Francia y 993 en Bélgica). El Performance Ratio (PR) promedio ha sido de 76% en Francia y 78% en Bélgica, y el Performance Index (PI) promedio es de 85% en ambos países. La potencia real media de los módulos fotovoltaicos es un 4,9% inferior a su valor nominal anunciado en la ficha técnica del fabricante. Los módulos de heterounión (HIT) muestran productividades superiores a la media, mientras que los módulos de Cobre-Indio-Selenio (CIS) muestran una potencia real un 16% inferior a su valor nominal
Review of the Performance of Residential PV systems in France
The main objective of this paper is to review the state of the art of residential PV systems in France. This is done analyzing the operational data of 6868 installations. Three main questions are posed. How much energy do they produce? What level of performance is associated to their production? Which are the key parameters that most influence their quality? During the year 2010, the PV systems in France have produced a mean annual energy of 1163 kWh/kWp. As a whole, the orientation of PV generators causes energy productions to be some 7% inferior to optimally oriented PV systems. The mean Performance Ratio is 76% and the mean Performance Index is 85%. That is to say, the energy produced by a typical PV system in France is 15% inferior to the energy produced by a very high quality PV system. On average, the real power of the PV modules falls 4.9% below its corresponding nominal power announced on the manufacturer's datasheet. A brief analysis by PV modules technology has led to relevant observations about two technologies in particular. On the one hand, the PV systems equipped with heterojunction with intrinsic thin layer (HIT) modules show performances higher than average. On the other hand, the systems equipped with the copper indium (di)selenide (CIS) modules show a real power that is 16% lower than their nominal value
Dealing in practice with hot-spots
The hot-spot phenomenon is a relatively frequent problem occurring in current
photovoltaic generators. It entails both a risk for the photovoltaic module's
lifetime and a decrease in its operational efficiency. Nevertheless, there is
still a lack of widely accepted procedures for dealing with them in practice.
This paper presents the IES-UPM observations on 200 affected modules. Visual
and infrared inspection, electroluminescence, peak power and operating voltage
tests have been accomplished. Hot-spot observation procedures and well defined
acceptance and rejection criteria are proposed, addressing both the lifetime
and the operational efficiency of the modules. The operating voltage has come
out as the best parameter to control effective efficiency losses for the
affected modules. This procedure is oriented to its possible application in
contractual frameworks.Comment: 6 pages, 13 figures, conference proceedings 29th European
Photovoltaic Solar Energy Conference and Exhibition, Amsterdam, 201
Equipment and procedures for ON-SITE testing of PV plants and BIPV
Actual system performance of a PV system can differ from its expected behaviour.. This is the main reason why the performance of PV systems should be monitored, analyzed and, if needed, improved on. Some of the current testing procedures relating to the electrical behaviour of PV systems are appropriated for detecting electrical performance losses, but they are not well-suited to reveal hidden defects in the modules of PV plants and BIPV, which can lead to future losses. This paper reports on the tests and procedures used to evaluate the performance of PV systems, and especially on a novel procedure for quick on-site measurements and defect recognition caused by overheating in PV modules located in operating PV installations
A bankable method for the field testingor a CPV plant
The bankability of CPV projects is an important issue to pave the way toward a swift and sustained growth in this technology. The bankability of a PV plant is generally addressed through the modeling of its energy yield under a b
aseline loss scenario, followed by an on-site measurement
campaign aimed at verifying its energetic behavior. The main difference between PV and CPV resides in the proper CPV modules, in particular in the inclusion of optical lements and III-V multijunction cells that are much more sensitive to spectral variations than xSi cells, while the rest of the system behaves in a way that possesses many common points with xSi technology. The modeling of the DC power output of a CPV system thus requires several impo
rtant second order parameters to be considered, mainly related to optics, spectral direct solar radiation, wind speed, tracker accuracy and heat dissipation of cells
Automatic detection of PV systems failures from monitoring validated on 10,000 BIPV systems in Europe
The installers and owners show a growing interest in the follow-up of the performance of their photovoltaic (PV) systems. The owners are requesting reliable sources of information to ensure that their system is functioning properly, and the installers are actively looking for efficient ways of providing them the most useful possible information from the data available. Policy makers are becoming increasingly interested in the knowledge of the real performance of PV systems and the most frequent sources of problems that they suffer to be able to target the identified challenges properly. The scientific and industrial PV community is also requiring an access to massive operational data to pursue the technological improvements further