| Data | Titolo | Abstract | | | |
| 08/05/2007 0.00.00 |
STAPELIA: LAMPIONE
FOTOVOLTAICO/COMPONENTE
MULTIFUNZIONALE PER L’INSERIMENTO IN
CONTESTI SENSIBILI (ELEMENTO ISOLATO
LUMINOSO CON FUNZIONAMENTO IN
MODALITÀ STAND-ALONE/GRID CONNCTED)
|
La diffusione dei sistemi fotovoltaici integrati in architettura
non può prescindere dal soddisfacimento dei requisiti estetici
che ne determinano la “accettabilità” da parte dei progettisti,
dei committenti e degli utenti; pertanto particolare rilievo
assume la messa a punto di componenti fotovoltaici
multifunzionali sviluppati tenendo conto del “punto di vista
dell’architetto”, che guarda ad essi come occasioni progettuali
alla stregua degli altri elementi del processo di design, se esso
viene utilizzato integrato nell’involucro edilizio, così come nel
paesaggio.
L’invenzione in oggetto concerne un componente
fotovoltaico luminoso multifunzionale pensato per
l’integrazione in siti “sensibili”, vale a dire pregevoli da un
punto di vista ambientale o anche storico-archeoogico.
In particolare si tratta di un lampione fotovoltaico, concepito
traendo spunto dalle forme di un fiore denominato “Stapelia”,
come verrà meglio chiarito in seguito. L’obiettivo è quello di
mitigare l’impatto visivo che l’inserimento di un sistema
fotovoltaico produce in un contesto sensibile, migliorandone
notevolmente la valenza formale.
| Pubblicazioni/2007/BrevettoStapelia.pdf | | 1340KB |
| 02/04/2007 0.00.00 |
Micromorph tandem solar cells: influence of microcrystalline silicon bottom cell on device performance
|
Micromorph tandem solar cells have been fabricated growing the intrinsic layers of both components
by VHF-PECVD at 100 MHz at low substrate temperature (150 °C). The influence of the microcrystalline p-layer on
the bottom cell has been studied by growing single microcrystalline devices. Different growth regimes have been
explored for the bottom cell by changing both chamber pressure and plasma power. The effect of the structural
composition of the microcrystalline absorber layer on the electrical parameters of the device has been investigated.
High short circuit current density and an almost constant FF in a wide silane concentration range are obtained when
using large power to pressure ratio (0.5 W/Pa). However low open circuit voltage is generally found in this regime.
The largest VOC values are found at 67 Pa and power to pressure ratio of 0.3 W/Pa, where the highest efficiency
(11.1%) is reached.
Keywords: Tandem, Micro Crystalline Si, Thin Film.
| Pubblicazioni/2007/Micromorph_tandem_solar_cells.pdf |
P. Delli Veneri, L. V. Mercaldo, P. Aliberti, P. Ciani, I. Usatii, C. Privato
Enea - Portici Research Center
Località Granatello - 80055 Portici (Napoli) – Italy
Tel: +39-0817723259, fax +39-0817723344, e-mail: paola.delliveneri@portici.enea.it
| 554Kb |
| 02/04/2007 0.00.00 |
A YEARLY ENERGY PRODUCTION OF 10KWP DOUBLE AXIS PV SYSTEM
FEEDING AN ELECTROLYSER FOR THE HYDROGEN PRODUCTION
|
Within the operating program aimed to on-site power generation, launched by Regione Campania for
the years 2000/2006, ENEA (Italian National Agency for New Technologies, the Energy and the Environment)
planned the installation of a double axis Photovoltaic Plant feeding an electrolyser for the hydrogen production. The
facility, which is located in the Research Centre of Portici near to Naples, has been monitored during its operating
first year. The PV generator is realized by 4 standard units of 2.4kWp each for a total power of 9.6kWp at STC. The
PV array includes 12 modules Sanyo Heterojunction with Intrinsic Thin layer HIP-200NHE1 mounted on the double
axis sun Deger Tracker 1600EL. The 10kW alkaline electrolyser for hydrogen production, operating at atmospheric
pressure, has been used. The focus of this work is to illustrate the energetic performance of PV plant after one
working year. As regard a comparative analysis among PV installations of different type - flat system, tilted single
axis tracking system, double axis tracking system - has been performed. Moreover a detailed economical analysis in
order to emphasize the economical and energetic advantages due to the use of the double axis tracking PV
technology has been developed.
Keywords: double axis PV system, energetic performance, technical and economical analysis.
| A_YEARLY_ENERGY_PRODUCTION_DOUBLE_AXIS_PV_SYSTEM.pdf |
G. Graditi, C. Cancro, A. Merola, C. Privato
Centro Ricerche ENEA - Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile.
Via Vecchio Macello - 80055 Portici (Napoli) - Italy
tel:+390817723400; fax:+390817723344
mail to: giorgio.graditi@portici.enea.it
| 77Kb |
| 02/04/2007 0.00.00 |
A PROCEDURE TO EVALUATE THE ENERGY PRODUCTION AND THE INCIDENCE OF
THE THERMAL LOSSES FOR A C-MODULE MOCK-UP
|
The comparison of the different loss factors of a C-module provides indications to optimize the design
of the component in terms of geometrical concentration and passive cooling, with the aim of minimize the cost for
the produced energy unit. In this work a detailed energy losses analysis of different C-module mock-ups have been
performed and the thermal losses incidence have been evaluated. The results show that, from statistical point of view,
the weight of the so named “circumsolar radiation” should not be neglected in order to: estimate the yearly energy
production, evaluate experimentally the efficiency of a PV C-module, select the right installation site from the
environmental specifications point of view.
The simplicity and flexibility of the proposed approach allow its application in a large number of cases to help the
design of a effective C-system.
Keywords: C-module energy performance, thermal losses, circumsolar radiation.
| Pubblicazioni/2007/PROCEDURE_TO_ EVALUATE_ENERGY_PRODUCTION_ AND_ INCIDENCE.pdf |
G. Contento(1), G. Graditi(2), F. Roca(2)
(1)ENEA Centro Ricerche, S.S. 7 Appia, km 713.700 - 72100 Brindisi, Italy
tel: +390831201430; fax: +390831201431; email: gaetano.contento@brindisi.enea.it
(2)ENEA Centro Ricerche, Località Granatello - 80055 Portici (NA), Italy
tel: +390817723400; fax: +390817723344
| 368Kb |
| 02/04/2007 0.00.00 |
IMPROVEMENTS IN THE PHOCUS C-MODULE OPTICAL DEVICES
|
The aim of this paper is the analysis of the influence of the different technological solutions developed for the optical
devices on the PhoCUS C-module energetic performance. Two concentration stages have been used: the first one is a
refractive optical lens and the second one is a reflective Secondary Optical Elements (S.O.E.). In particular two types
of primary optics have been developed: the Prismatic and the Hybrid lens. The Prismatic lens is made of an array of
square refractive prisms of size 7,8x7,8 mm2 in the central portion, and 3,9x3,9 mm2 in the peripheral areas. The
hybrid lens is made of prismatic refractive prisms in the central portion, and Fresnel grooves in the peripheral region.
The comparison of the behaviour of these devices in different working conditions has been carried out; the results
show that the optical efficiencies of prismatic and hybrid lens are very closely.
The S.O.E. has the shape of a truncated inverted pyramid with one tilt angle; it is realized by a plastic case with a
metallic inner surface used as a reflector. The influence of two different types of aluminium sheet (unpolished or
polished), used as reflective materials, has been investigated by means many indoor and outdoor tests. The results
shown an increase of the optical efficiency, for the polished aluminium, about of 3%. Finally several tests in order to
define the optical acceptance of the C-module have been performed: the result show that the use of the S.O.E. allows
an acceptance angle about of ±0,6°.
Keywords: Concentrators; Optical Losses; Hybrid lens
| Pubblicazioni/2007/IMPROVEMENTS_IN_PHOCUS_C_MODULE_OPTICAL_DEVICES.pdf |
C. Cancro1, G. Graditi, A. Romano, R. Fucci
(1)ENEA R. C. Portici, Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile
via Vecchio Macello, località Granatello, 80055 Portici (NA), Italia
mail to: carmine.cancro@portici.enea.it phone +39 081 7723278 fax +39 081 7723344
| 164Kb |
| 02/04/2007 0.00.00 |
OPTIMIZATION OF THE CONTACTING STRUCTURE OF HIGH EFFICIENCY C-SI SOLAR CELLS
FOR CONCENTRATING SYSTEMS
|
In the present work we have investigated the influence of metal grid and assembly on the cell
performance at one sun and under concentrated light. A conventional solar cell structure has been used and a number
of devices with metal grids having similar shadowing but different width and spacing between fingers have been
realised. The finger width was restricted to the lower values technologically feasible considering the future
industrialisation of this process, namely transferring the concentration solar cell technology from lab-scale to prepilot
level. The very high current level of this kind of devices imposed the use of thick fingers/busbar on the
contacting structure in order to reduce the ohmic losses. We made a comparative study of the electrical behaviour of
different devices (current-voltage and quantum efficiency characterization) at one sun and under concentrated light,
before and after assembling, to investigate the influence of different metal grid on the electrical performances of the
devices. The best cell realized in our laboratory achieved the efficiency of more than 20% at 1 sun, 21% at 100 suns
and more than 19% at 180 suns.
Keywords: c-Si, Concentrator Cells, High Efficiency.
| Pubblicazioni/2007/OPTIMIZATION_CONTACTING_STRUCTURE_HIGH_EFFICIENCY_C-SI_SOLAR_CELLS.pdf |
P. Morvillo*, E. Bobeico, G. Flaminio, F. Formisano, R. Fucci, F. Roca
C.R. ENEA Portici
Loc. Granatello, I-80055 Portici (Napoli), Italy
*Email: Morvillo@portici.enea.it
| 148Kb |
| 02/04/2007 0.00.00 |
OPTIMIZATION OF THE LIGHTING PHOTOVOLTAIC COMPONENT STAPELIA
|
In Summer 2006 five prototypes of a PV lighting component called Stapelia have been realized and
installed in the garden of the ENEA (Italian National Agency for New Technologies, the Energy and the
Environment) Research Centre in Portici.
Stapelia is fit to the integration in valuable sites; its shape, and consequently its name, have been inspired by the
structure of the homonymous tropical flower. The geometry is based on a pentagon, and the basic idea is that one or
more elements (flowers) can be “planted” where an electrical supply or a places improvement are required.
A good design would be the most important feature of this PV component, ensuring a good matching with the
context (landscape or valuable places), and also a satisfying balance between the different functions the component
has.
Stapelia has been patented as utility model, industrial design, registered community trade mark, and an Italian
company has been granted a commerce and production license. At the moment an optimization process is involving
different Enea units, focusing on the single aspects that have been integrated into the design of Stapelia and
monitoring the real performance of the component (lighting, photovoltaic energy generation).
A comparative analysis of the best solutions (among the investigated ones), ensuring a good balance between the
energetic and lighting performance, and the costs is in progress All the solutions are analyzed in order to preserve the
“aesthetic” value of the component.
Keywords: building integration, PV lighting component, diffusion
| Pubblicazioni/2007/OPTIMIZATION_LIGHTING_PHOTOVOLTAIC_COMPONENT_STAPELIA.pdf |
A. Scognamiglio*, C. Cancro*, F. Formisano*, C. Privato* and S. Fumagalli**, G. Leonardi**
*ENEA Portici Research Centre, località Granatello, 80055 Portici (NA), Italy
**ENEA Ispra Research Centre, via Fermi 2749 TP144, 21020 Ispra (VA), Italy
mail to: alessandra.scognamiglio@portici.enea.it; phone +39 081 7723304 fax +39 081 7723344
| 349Kb |
| 02/04/2007 0.00.00 |
MULTI-SOURCE PULSED REFLECTOMETER FOR FAST OPTICAL MAPPING
OF A PV MODULE
|
An innovative, non destructive, method and the relative apparatus for the optical mapping of large
photovoltaic surfaces, i.e. photovoltaic modules and large optical windows, is described. The method has been
applied by the following procedure: illuminating a portion of the test surface by a collimated and pulsed beam,
incident on the surface at a variable angle between 0° e 70°; measuring the total or diffuse hemispherical reflectance;
translating the sample on the x-y plane; building a map of optical reflectance of the test surface for each angle of
incidence. The method is particularly useful for the analysis of the optical properties of crystalline Silicon modules
and for the analysis of the optical and electrical properties of integrated thin films modules (a-Si, CIS), when
photocurrent measurements are made simultaneously to the optical measurements.
Keywords: Reflectometer, Optical Losses, PV Module
| Pubblicazioni/2007/MULTI-SOURCE_PULSED_REFLECTOMETER_ FOR_ FAST_OPTICAL_MAPPING.pdf |
A. Parretta*1,2, G. Nenna3, G. Flaminio3, R. Schioppo4, A. Aldrin5
1ENEA Centro Ricerche “E. Clementel”, Via Martiri di Monte Sole 4, 40129 Bologna (BO), Italy.
2Physics Department, University of Ferrara, Via Saragat 1, 44100 Ferrara (FE), Italy.
3ENEA Centro Ricerche Portici, Località Granatello,80055 Portici (NA), Italy.
4ENEA Area Sperimentale M.te Aquilone, S.S. Garganica 89, 71043 Manfredonia (FG), Italy.
5Universitat de Barcelona, Departament de Física Aplicada i Òptica Martí i Franquès, 1-11,
5ª Planta, 08028-Barcelona, Spain
*Phone: +39 (0)51 6098617; Fax: +39 (0)51 6098767; E-mail: antonio.parretta@bologna.enea.it
| 370Kb |
| 02/04/2007 0.00.00 |
FIELD TESTING OF THE PhoCUS SOLAR TRACKER BY MEANS OF A NOVEL OPTOELECTRONIC DEVICE
|
The focus of the paper is to evaluate the solar
tracker accuracy, installed in R.C. ENEA in Portici (NA)
within the PhoCUS (Photovoltaic Concentrators to Utility
Scale) project, using a novel optoelectronic device (OED)
designed and patented by ENEA [1]. In this work a
detailed analysis of the misalignments causes, considering
the influence of the different factors (mechanical and
thermal deformations, set-up errors, inefficiency of
feedback, etc.), has been performed by the authors. On
the basis of the experimental data, collected in absence of
feedback, an accurate improvement of the feedback
algorithm has been obtained. After, several outdoor tests
in presence of feedback sensor have been carried out.
The results have been shown an high increase of the
tracking accuracy.
| Pubblicazioni/2007/Madrid_ENEA_Field testing.pdf |
C. Cancro, G. Graditi, G. Leanza, F. Pascarella, A. Sarno and D. Mancini*
Center Research ENEA (Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile)
Via Vecchio Macello 80055 Portici (NA), Italy - Tel: +3908177232111; Telefax: +390817723344
*Atec Robotics, via G. Nicotera 10, 80132 Napoli - Tel: +390814421546; Telefax: +390812110228
Corresponding author: carmine.cancro@portici.enea.it
| 639KB |
| 02/04/2007 0.00.00 |
DEVELOPMENT AND PERFORMANCE ANALYSIS OF THE PHOCUS C-MODULE
|
Relevance is given in the ENEA PhoCUS project for
the development of a new technology able to realize a
monolytic low-cost photovoltaic module suitable to work
under medium concentration (200X).
Several technical problems were faced and
overcome about the development of the solar cells, the
system housing integrating optics and receivers, the
realization of the lenses and heat spreaders and the
mechanical-thermal and electrical performance modelling.
In order to meet the low cost requirement a large use
of conventional materials and components together with
manufacturing and assembling techniques addressed to a
cheap full automation have been adopted in cooperation
with national industrial operators.
The efforts made brought to file many patents
relating the novel solutions, as for the C-module, the
optics. A final product meeting requested requirements
was obtained. The paper will report about the indooroutdoor
characterization and the detailed performance
analysis with also comparison to expected values.
| Pubblicazioni/2007/Madrid_ENEA_Phocus Module.pdf |
F. Roca*, C. Cancro, R. Fucci, G. Flaminio, G. Graditi, G.Leanza, C. Privato, A. Romano, A. Sarno,
ENEA Portici Research Center Via Vecchio Macello 80055 Portici (NA), Italy
Tel: +390817723270; Telefax: +390817723344
*Corresponding author: roca@portici.enea.it
| 335KB |
| 02/04/2007 0.00.00 |
ENEA’S EXPERIENCE ON THE PV-CONCENTRATORS TECHNOLOGY:
THE PHOCUS PROJECT
|
The PhoCUS (Photovoltaic Concentrators to Utility
Scale) project was outlined in order to develop a low-cost
photovoltaic concentrators (PV-C) technology, based on
the point focus approach, to be applied in Mediterranean
climates, like Southern Italy.
The first phase of the project was over: the
technology for each device and component was
developed, the prototypes were realized and the first
demonstrative and experimental systems were installed
becoming operative. The experimental results coming
from field testing are proving the effectiveness, in terms of
operating efficiency and reliability, of the adopted
technological options.
The characterization of the single components
together with the understanding of the initial failures has
allowed to identify the critical points and to apply some
modifications in terms of hardware and of assembling
procedure.
The production cost of the main components
(module and heliostat) are strongly dependent on the size.
Economical analysis has shown that the cost reduction
expected for a mass production is not enough to make
PV-C technology competitive: the key factors for the
success are higher efficiency solar cell together with
higher concentration ratio and scale economy. Anyway, it
is important to get a reliability level comparable with the
flat plate PV in terms of life time.
The paper will report the Enea’s experience acquired
and on the basis of a sensitivity economic analysis and the
second phase of the PhoCUS project will be outlined.
| Pubblicazioni/2007/Madrid_EneaPhocusGeneral.pdf |
Angelo Sarno*, Felice Apicella, Michele Pellegrino, Carlo Privato, Francesco Roca
Enea Portici Research Center Loc.Granatello 80055 Portici (Napoli) - Italy –
(*) Corresponding author: sarno@portici.enea.it Tel: +390817723202;Fax: +390817723344
| 379KB |
| 25/05/2006 0.00.00 |
ZNO protetto
|
protetto
| Pubblicazioni/2006/ZnO 3DV.3.33.pdf |
protetto
| 565KB |
| 24/05/2006 0.00.00 |
A LANDSCAPE INTEGRATED PHOTOVOLTAIC COMPONENT CALLED “STAPELIA”
|
An important subject to investigate in the field of the diffusion of photovoltaic systems is the
development of landscape integrated PV components fit to the installation in valuable sites, that are characterized by
an high cultural value (such as archaeological areas, natural parks, small islands). The aesthetic value of the
components is the most important feature to ensure a good matching with the context (landscape or valuable places),
that means the acceptability of the energy solar generators. This work is focused on the design of a photovoltaic
lighting component fit to the integration in valuable sites, “Stapelia”, which shape, and consequently name, have
been inspired by the structure of the homonymous tropical flower. The geometry is based on a pentagon, and the
basic idea is that one or more elements (flowers) can be “planted” where an electrical supply or a places improvement
are required. Five prototypes of Stapelia have been realized and installed in the garden of the ENEA (Italian National
Agency for New Technologies, the Energy and the Environment) Research Centre in Portici, that is located within
the area of the Vesuvio National Park, on the sea front.
Keywords: building integration, diffusion, PV lighting component
| Pubblicazioni/2006/Stapelia 6DV 4 11.pdf |
A. Scognamiglio, C. Cancro. F. Formisano, G. Graditi, C. Privato
mail to: alessandra.scognamiglio@portici.enea.it; phone +39 081 7723304 fax +39 081 7723344
ENEA R.C. Portici, località Granatello, 80055 Portici (NA), Italy
| 297KB |
| 23/05/2006 0.00.00 |
COMPARISON BETWEEN TWO DIFFERENT S.O.E. GEOMETRICAL SHAPES
TO INCREASE THE PhoCUS C-MODULE ENERGY PERFORMANCES
|
The focus of this work is to present the energetic performance of a Concentration module (C-module)
using different configurations of Secondary Optical Element (S.O.E.). The use of S.O.E. can give the following
technical advantages: the level of precision of the solar tracker may be lower, the plastic is protected from dangerous
outside fire, intrinsic losses in case of non-optimal tracking are reduced, the energy flux over the cell is quite uniform
and global costs of the systems are limited. Two S.O.E. which differ in terms of shape have been considered. The
first has the shape of a truncated inverted pyramid with one tilt angle; the second has the shape of a truncated
overturned pyramid with tree different tilt angles. The solar cell is doweled under the pyramid’s bottom squared hole
having the same size of the solar cell. The S.O.E. reflective inner surface has been made of aluminium covered by a
reflecting polymeric film (3M Radiant Mirror Film). The experimental tests and numerical simulations have been
carried out considering a PV C-system which includes the following elements: prismatic lens, SOE and solar cell.
The tests have been performed considering a misalignments range of 0÷1,2° for the solar beam radiation respect to
prismatic lens. By means of the software TracePro Expert raytracing simulations have been carried out in order to
evaluate the optical efficiency of the lens-secondary system and the non-uniformity of the light flux on the target
where the cell is located. Many indoor tests to characterize the S.O.E. optical efficiency in misalignment conditions
have been carried out. The PV C-system is assembled in rugged Mock up and fixed on a rotation stage on the optical
bench with the solar cell in its focus. It can rotate on its own axis causing a misalignment between the lens and the
solar beam direction. Besides, by means of an other experimental Mock-up, motorized by a very accurate tracking
system, the S.O.E. efficiency has been measured outdoor. The measured optical efficiencies for the above mentioned
S.O.E. configurations have been compared in order to select the best solution and consequently to increase the Cmodule
energy performance.
Keywords: C-module, secondary optical element, energetic performance, technological features.
| Pubblicazioni/2006/SOE 5AV.3.16.pdf |
C. Cancro(1), R. Fucci(1), G. Graditi(1), A. Romano(1), A. Antonini(2), M. Armani(2)
(1)ENEA R.C. Portici, località Granatello, 80055 Portici (NA), Italy
(2)Dipartimento di Fisica Università di Ferrara, Via Paradiso 12, 44100 Ferrara, Italy
mail to: carmine.cancro@portici.enea.it; phone +39 081 7723111 fax +39 081 7723344
| 243KB |
| 22/05/2006 0.00.00 |
THERMAL CONTROLLED FLASH TIME ADJUSTABLE SOLAR SIMULATOR
FOR CONCENTRATING PV CELLS
|
Concentrating Photovoltaic technology has been requiring new attention after many stops and goes
attempts for the past. Due to the importance of the efficiency of the cell for its impact on the economical aspects and
technical feasibility of the technology, it is vital to measure in an easily and reliable way the cell electrical
characteristics. Unfortunately at the moment there are not many solar simulators specifically designed to perform the IV
under illumination characteristic for concentrating cells of certain dimensions, let aside some commercial equipments
for small size cells or not marketable built-in devices or various adjustments of solar simulators for flat panels. So in
order to fill this critical gap, a project aimed to design a solar simulator for characterising concentrating photovoltaic
cells of different sizes and for different suns was devised. The paper intends to describe the equipment and to give a
report of an experimental campaign.
Keywords: Concentrator cells, characterization
| Pubblicazioni/2006/Simulatore 5AV.3.14.pdf |
M. Pellegrino, C. Cancro, G. Flaminio, M. Marciano, C. Privato, F. Roca, A. Romano and A. Sarno
ENEA Centro Ricerche Portici
Località Granatello. P.O. Box 32, I-80055 Portici (NA), Italy.
tel:+39-81-7723-267, Fax:+39-81-7723-344
| 157KB |
| 21/05/2006 0.00.00 |
OPTIMIZATION PROCEDURES OF CONCENTRATOR PHOTOVOLTAIC MODULES BASED ON ENERGY
COST AND REALISTIC REPORTING CONDITIONS
|
The use of concentrator solar cells in photovoltaic plants significantly reduces the number and area of
expensive cells and contributes to reduce the total system cost; photovoltaic concentrator (PV-C) modules optimization
involves heat transfer analysis, system performance modelling, cost estimation, material selection applies to lenses, solar
cells, heat spreaders, heat sinks, etc. The aim of this work is the development of the cell assembly for the PhoCUS project;
this optimization process is based on energy cost. Some calculation methodologies are proposed, which allow to determine
the main characteristics of a PV-C module, starting from some experimental measurements of appropriate mock-up in real
working conditions. It has been developed and used an empirical model, based on this information, to obtain an optimum
combination of the different structures (optimization based on energy cost) for a particular geographical site (Real Reporting
Conditions).
Keywords: Concentrator, Modelling, Simulation
| Pubblicazioni/2006/Modules 5AV.3.20.pdf |
R. Fucci, G. Flaminio, G. Leanza, A. Romano, F. Roca
ENEA Research Center Portici – Località Granatello 80055 – Naples – Italy
email:fucci@portici.enea.it
| 157KB |
| 20/05/2006 0.00.00 |
THERMAL MODELLING OF THE BASIC UNIT OF A C-MODULE
|
The analysis of the thermal performance of a PV concentrator system (PV-C system) is necessary to
estimate the energetic yearly production. Moreover, an important goal for the designer is to select the optimal
configuration of the basic unit of the C-module (PV Concentrator module) in order to minimize the cost of kWh. In
this work a calculation procedure developed by the authors is described: it allows to obtain a suitable thermal model
for each configuration of the basic unit of a C-module. The model takes into account the radiative heat transfer and
power geometric concentration too. Regarding cooling by natural convenction, instead, it uses a simple yet accurate
analytically-based correlation suitably modified and extended by the authors to adapt it to photovoltaic applications.
The model has been tested for the C-module basic unit of the PhoCUS (Photovoltaic Concentrator to Utility Scale)
project performed by ENEA in Portici Research Centre. The results have been compared with those obtained by
means of the Computational Fluid Dynamics (CFD) software such as the Fluent. The model well fits the results
obtained by the Fluent with the advantage of a greater flexibility and speed in the resolution of the problem.
Keywords: Thermal Performance, Modelling, PV Concentrator Module
| Pubblicazioni/2006/Modelling 5AV.3.19.pdf |
(1)ENEA R.C Brindisi, SS 7 km 714, 72100 Brindisi, Italy
(2)ENEA R.C. Portici, località Granatello, 80055 Portici (NA), Italy
(3)DETEC Naples University Federico II, piazzale Tecchio, 80125 Napoli, Italy
mail to: gaetano.contento@brindisi.enea.it; phone: +39 0831 201430; fax: +39 0831 201431
| 214KB |
| 19/05/2006 0.00.00 |
DEPOSITION PRESSURE EFFECTS ON THE PERFORMANCE OF MICROMORPH TANDEM SOLAR CELLS
GROWN BY VHF-PECVD
|
“Micromorph” tandem solar cells consisting of an amorphous silicon top cell and a microcrystalline
silicon bottom cell represent an elegant way of overcoming the efficiency limits of single-junction solar cells and
reducing the light induced degradation of amorphous silicon films. These devices allow a good utilization of the solar
spectrum due to the bandgap values of the two materials.
In this work micromorph tandem solar cells have been realized on Asahi U-type TCO-covered glass substrates. The
intrinsic layer of both the amorphous top cell and the microcrystalline bottom cell are grown by VHF-PECVD at
100MHz at low substrate temperature (150 °C). For the bottom cell, low pressure-low power and high pressure-high
power regimes have been explored aiming at growing high quality microcrystalline silicon at large deposition rates.
The effect of the structural composition of the microcrystalline absorber layer on tandem device performance has
been investigated. A preliminary evaluation of device stability has been done by exposing the tandem solar cells to
white light for 200 hours. An initial efficiency of 11.3 % has been obtained.
Keywords: Tandem, Micro Crystalline Si, Degradation.
| Pubblicazioni/2006/Micromorph 3DV.3.21.pdf |
P. Delli Veneri, L. V. Mercaldo, M. L. Addonizio, M. Ferrara, C. Privato
Enea - Portici Research Center
Località Granatello - 80055 Portici (Napoli) - Italy
| 55KB |
| 18/05/2006 0.00.00 |
THE HYBRID LENS: A NEW CONCEPT TO CONCENTRATE THE SOLAR BEAMS
|
The aims of this paper are the description of a new optical device created for C-modules, named
“hybrid lens”, and its comparison with the prismatic lens. In the PhoCUS project, a prismatic lens has been designed
and developed. Prismatic lens is made of an array of square refractive prisms of size 7,8x7,8 mm2 in the central
portion, and 3,9x3,9 mm2 in the peripheral areas. The hybrid lens is made of prismatic refractive prisms in the central
portion, and Fresnel grooves in the peripheral region. In this way, the prismatic portion of the lens creates a uniform
distribution of solar beam on the cell and the Fresnel lens region increases the efficiency in the peripheral areas since
the total length of Fresnel groves edges is shorter than that one of squared refractive prism in the prismatic lens.
Simulations by the ray tracing software TracePro Expert have been carried out in order to evaluate the optical
efficiency and the non-uniformity of the light flux on the target for the lens, without any kind of manufacturing
defects. The optical efficiency has been estimated as 91% in the ideal case and as 84% considering manufacturing
defects; it has been evaluated considering the ratio between the energy flux achieving the solar cell and that
impinging on the external surface of the lens. Many indoor and outdoor tests have been carried out to determine the
lens behaviour on the first prototype. These studies have shown that the hybrid lens potentially has an higher
efficiency than the prismatic lens about of 5% in the peripheral areas.
Keywords: Concentrators; Optical Losses; Ray Tracing
| Pubblicazioni/2006/Lens 5AV.3.15.pdf |
C. Cancro1, G. Graditi, M. Pellegrino, C. Privato, A. Romano, A. Antonini2
(1) ENEA R. C. Portici, Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA).
via Vecchio Macello, località Granatello, 80055 Portici (NA), Italia
(2) Dipartimento di Fisica Università di Ferrara, via Paradiso 12, 44100 Ferrara, Italy
mail to: carmine.cancro@portici.enea.it phone +39 081 7723278 fax +39 081 7723344
| 296KB |
| 18/05/2006 0.00.00 |
PERFORMANCES CHARACTERIZATION OF CONCENTRATION SOLAR CELLS BY MEANS OF
I-V AND LIFETIME MEASUREMENTS MADE WITH THE QSSPC TECHNIQUE
|
In this work we compare the IV curves of concentration devices obtained with a standard solar
simulator with that obtained using a PCD technique with the aim to extract resistive components of the cells.
Different substrates and emitter doping profiles are analyzed. Results show that, at medium-high light concentration,
where ohmic effects are relevant, the method we propose allows to easily measure the series and shunt resistance of
the cells.
Keywords: Concentration solar cells; series resistance.
| Pubblicazioni/2006/lifetime 2DV.2.8.pdf |
Santolo Daliento1, Luigi Mele1, Laura Lancellotti2, Pasquale Morvillo2, Eugenia Bobeico2, Franco Roca2 Luisa Pirozzi3.
1Dipartimento di Ingegneria Elettronica e delle TLC, Università “Federico II” di Napoli,
Via Claudio 21, 80125, Napoli Italy, email: daliento@unina.it
2C.R. ENEA località Granatello, Portici, Italy, email: lancellotti@portici.enea.it, morvillo@portici.enea.it
3C.R. ENEA La Casaccia, Roma, Italy
| 415KB |
| 17/05/2006 0.00.00 |
THIN FILM MODULES OPERATIONAL EXPERIENCE IN MEDITERRANEAN CLIMATE
|
ENEA, the Italian National Agency for Energy and New Technologies within the frame of R&D and
Demonstration activities of Photovoltaics in collaboration with KANEKA started a survey of building integrated a-Si thin
film modules in order to test and compare their operational performance versus the other PV technologies and to collect data
about their use in aggressive climatic conditions, such it can be for the near the sea installations, in Mediterranean climate.
At first 1 kWp plant with a-Si single junction modules has been put in operation since June 2002 and then a second plant of 1
kWp with the new hybrid a-Si/μc-Si modules was installed at the beginning of January 2006.
The paper reports the global and annual performance of both the plants data in order to make a comparison of array and
modules of different size and technology with the other PV operational experience in the world. Data collected after a
few years of continuous monitoring are shown for the previous plant. For the new plant we will report the experimental
new storage data. This in-depth analysis is important since the thin-film technology is still in the process to gain a wider
acceptance in the photovoltaic markets, due to the opened questions concerning its long term performance, the stability to
the degradation, the reliability and expected lifetime that have contributed for the past to give a damaged image at the
first module prototypes.
Keywords: Building integration - 1: Thin film module - 2: Performance - 3: Environmental effect
| Pubblicazioni/2006/Kaneka 5BV_3_18.final.pdf |
F. Apicella1, V. Giglio1, M. Pellegrino1, S. Ferlito1, F. Tanikawa2, Y. Okamoto2
1 Centro Ricerche ENEA -Loc. Granatello - 80055 Portici (NA) - Italy
Tel.+390817723400; Fax+390817723344; e-mail: felice.apicella@portici.enea.it
2 Kaneka Corporation - Osaka, 530-8288, Japan Tel. +81662265315 Fax +81662265144
| 201KB |
| 16/05/2006 0.00.00 |
KEY ISSUES FOR THE IMPROVEMENT OF THE INTERFACE AND EMITTER QUALITY IN a-Si-:H/c-Si
HETEROJUNCTION SOLAR CELLS
|
The development of a cheaper, medium-thick polycrystalline ribbon silicon or similar material grown on
glassily or other low cost substrates is an important topic of photovoltaic R&D to overcame the shortage of the Si
feedstock is becoming a serious problem limiting further growth of PV market. The predicted materials impose low
temperature approach for the surface passivation-conditioning and amorphous-crystalline silicon heterojunctions (SHJ)
could be the solution. A necessary step toward further application of SHJ to the new class of materials is a better
knowledge of the a-Si/c-Si interface structural, morphological and electrical modifications occurring during the various
steps of the SHJ preparation. These steps include the c-Si substrate conditioning (wet and dry cleaning), the kinetics of
SiH4-H2 based plasma ignition and the interaction with hydrogen-based species (H-atoms, Si-H, Si-H2, Si-H3 radicals)
impinging and diffusing into the c-Si substrate. This contribution discusses the impact of the c-Si surface treatments on
its interaction with hydrogen and on the interface and emitter quality in a-Si:H/c-Si heterojunction solar cells
Keywords: Heterojunction, Silicon, Interfaces
| Pubblicazioni/2006/Heterojunction 3AO.8.2.pdf |
F. Roca1, E. Bobeico, M. Della Noce, P. Delli Veneri, L. Lancellotti, F. Formisano, L. Mercaldo, P. Morvillo,
, M. M. Giangregorio, G.V. Bianco, A. Sacchetti, M. Losurdo, G. Bruno2
1ENEA Portici Research Centre – Località Granatello-80055 Portici (Naples) Italy
Tel: +39081-7723 270; e-mail: roca@portici.enea.it
2Istitute of Inorganic Methodologies and of Plasmas, IMIP-CNR, Via Orabona 4, 70126 Bari, Italy
Tel: +39080-5442094; e-mail: giovanni.bruno@ba.imip.cnr.it
| 357KB |
| 15/05/2006 0.00.00 |
METAL GRID OPTIMIZATION OF C-SI SOLAR CELLS FOR CONCENTRATING SYSTEMS
|
In the present work we have investigated the influence of metal grid on the cell performance of c-Si
devices at one sun and under concentrated light. We have performed the modelling of the ohmic losses and different
solar cells were realized by using metal grids having similar shadowing but different width and spacing between
fingers. The first one was restricted to the lower values technologically feasible considering the future
industrialisation of this process, namely transferring the concentration solar cell technology from lab-scale to prepilot
level. The finger spacing was calculated and selected bearing in mind low shadowing and by taking into account
the chosen finger width and height. The very high current level of this kind of devices imposed the use of thick
fingers/busbar on the contacting structure in order to reduce the ohmic losses. We made a comparative study of the
electrical behaviour of different devices (current-voltage and quantum efficiency characterization) at one sun and
under concentrated light, to investigate the influence of different metal grid on the electrical performances of the
devices. The best cell realized in our laboratory achieved the efficiency of more than 19.5% at 1 sun, 20.5% at 100
suns and more than 19% at 160 suns.
Keywords: c-Si, Concentrator Cells, High Efficiency.
| Pubblicazioni/2006/Dresda 2006 PV-C Cell 1DV.1.13.pdf |
E. Bobeico, L. Lancellotti, P. Morvillo, F. Roca
C.R. ENEA Portici
Loc. Granatello, I-80055 Portici (Napoli), Italy
| 97KB |
| 14/05/2006 0.00.00 |
A 9,6KWP DOUBLE AXIS PV SYSTEM INSTALLING HIT MODULES:
TECHNICAL AND ECONOMICAL EVALUATION
|
Regione Campania launched for the years 2000/2006 an operating program aimed to on-site power
generation by means of both traditional and renewable sources in order to verify the technical and economical
potentials for electrical energy generation and distribution. Many stakeholders joined the Project: Universities,
Private Companies, Research Centers. Within this framework ENEA planned the installation in the Portici Research
Centre of a 9,6kWp double axis Photovoltaic (PV) plant feeding an electrolyser for the hydrogen production. The
focus of this work is to present the first experimental energetic results of the PV plant by comparing these data with
those obtained by means of the numerical simulations. The PV generator includes 4 standard units of 2.4kWp each
one at STC (Standard Test Conditions) and it is connected to the public low voltage electrical distribution network
(230V, 50Hz) by two inverters. The standard unit is composed of 12 modules Sanyo Heterojunction with Intrinsic
Thin (HIT) layer HIP-200NHE1 mounted on the double axis soloar tracker (Deger Tracker 1600EL). The HIT PV
modules have been characterised by ENEA by means of a class A simulator at STC. Furthermore an economical
analysis has been developed by the authors to compare the cost per kWh of the PV plant under investigation with the
one of a fixed PV plant.
Keywords: double axis PV system, HIT modules, energetic performance, economical analysis.
| Pubblicazioni/2006/CRdC 5BV.3.4.pdf |
G. Graditi, C. Cancro, M. Pellegrino, C. Privato, A. Scognamiglio
ENEA R.C. Portici, Località Granatello, 80055 Portici (NA), Italy
mail to: giorgio.graditi@portici.enea.it phone +39 081 7723400 fax +39 081 7723344
| 97KB |
| 14/05/2006 0.00.00 |
Polymer protetto co password
|
protetto
| Pubblicazioni/2006/Polymer substrates 3DV.3.32.pdf |
protetto
| 406KB |
| 12/05/2006 0.00.00 |
ASSESSMENT OF THE PHOCUS /PV-C TECHNOLOGY: TECHNICAL FEATURES AND ECONOMICAL
ASPECTS
|
The main purpose of the PhoCUS (Photovoltaic Concentrators to Utility Scale) project performed by
ENEA (Italian Agency for New Technologies, Energy and Environment) in close cooperation with some national
industrial operators, was aimed to the development of a low-cost photovoltaic concentrators technology (PV-C
technology) based on a medium concentration factor, to be applied in Mediterranean climates, like Southern Italy.
The PhoCUS concentration factor, fixed at 200X , is achieved by means of a primary optics based on refractive
lenses able to be integrated into the PV module. In the frame of the project, several technical problems was faced and
overcome. In order to meet the low cost requirement a large use of conventional materials and components together
with manufacturing and assembling techniques addressed to a cheap full automation have been adopted. The first
phase of the project was completed. The efforts made brought to file many patents relating the novel solutions, as for
the C-module, the optics, and the tracking control. The technical results coming from the experimental activities will
be presented and discussed in the present paper. Their comparison with the expected values together with a detailed
cost analysis will allow to make an intermediate assessment of the PhoCUS technology in order to outline the future
activities.
Keywords: Concentrator Cells, module, tracking
| Pubblicazioni/2006/5DO 7 4_new.pdf |
ASSESSMENT OF THE PHOCUS /PV-C TECHNOLOGY: TECHNICAL FEATURES AND ECONOMICAL
ASPECTS
| 520KB |
| 01/05/2006 0.00.00 |
BOOGIE-WOOGIE, A PHOTOVOLTAIC GLASS-GLASS MODULE “DANCING” WITH THE BUILDING
|
The focus of this work – that is included in the Enea (Italian Agency for New Technologies, Energy
and the Environment) activities in the field of the development of innovative building integrated photovoltaic
components - is the development of an innovative photovoltaic module by means of tested industrial techniques, in
order to allow a large scale production without increasing the costs. The project of a photovoltaic glass-glass module
named “Boogie-Woogie” has been carried out and patented. The main feature of the component is its high aesthetic
value depending on the design parameters, providing a relevant contribution to the improvement of the appearance of
the building. In fact it can offer the designers the possibility of designing façades and coverings suiting a good quality
of internal and external building spaces. It has been developed to be seen from the front side as well as from the back
one, the cells pattern is random, and the electrical grids can contribute to a satisfying image of the component,
ensuring a good satisfaction of designers, customers and users. An interesting field of utilization of Boogie-Woogie
photovoltaic module can be identified with representative or symbolic buildings (especially public ones), where an
important role is played by communicative aspects and by innovations acceptability.
Keywords: building integration, façade, PV module
| Pubblicazioni/2006/Boogie 6DV 4 12.pdf |
A. Scognamiglio, G. Graditi, F. Pascarella, C. Privato
mail to: alessandra.scognamiglio@portici.enea.it phone: +39 081 7723304 fax +39 081 7723344
ENEA R.C. Portici, località Granatello, 80055 Portici (NA), Italy
| 513KB |
| 24/05/2005 0.00.00 |
TECHNOLOGY FOR THE PRODUCTION OF 20% EFFICIENCY C-SI SOLAR CELLS FOR
CONCENTRATING SYSTEMS
|
In the present work we have investigated the best working-conditions applied to crystalline silicon
technology developed in ENEA laboratories to transfer the concentration solar cell technology from lab-scale to prepilot
level. We have realized different devices using FZ p-type Boron doped wafers and varying the sheet resistance
of the emitters aiming at analyzing the effects of junction depth and concentration on the surface of doped elements
affecting the recombination process. The very high current level of this kind of devices (Jsc: 1 up to 8 A/cm2)
imposed the use of thick fingers/busbar on the contacting structure in order to reduce the ohmic losses. Our aim is to
develop a process easily transferable to industrial scale. A simplified photolitographic sequence to realize a thick
layer of photoresist (>15 μm) followed by evaporation was used. We made a comparative study of the electrical
behavior of different devices (current-voltage and quantum efficiency characterization) at one sun and under
concentrated light, to investigate the influence of different fabrication conditions on the electrical performances of
the devices. The best result achieved is η> 20% at 100 suns.
Keywords: c-Si, Concentrator Cells, High Efficiency.
| Pubblicazioni/2005/Cella2CV.pdf |
E. Bobeico, G. Flaminio, G. Gerla, L. Lancellotti, N. Martucciello, P. Morvillo, F. Roca, C. Vernetti
C.R. ENEA Portici, Loc. Granatello, I-80055 Portici (Napoli), Italy
| 142KB |
| 21/05/2005 0.00.00 |
EXPERIMENTAL DETERMINATION OF THE DISSIPATION SYSTEM THERMAL BEHAVIOUR FOR
CONCENTRATOR PHOTOVOLTAIC CELLS
|
The use of concentrator solar cells in photovoltaic plants significantly reduces the number and area of
expensive cells and contributes to reduce the total system cost. Unfortunately the remarkable power concentration
weighing upon limited areas is only partially turned into electric energy; therefore its dissipation towards the outside
becomes necessary. The characterization of the thermal dissipation structures used turns out to be necessary, in order to
highlight its effectiveness in real working conditions. As the theoretical analysis of the heat transfer is a very
complicated task, it is usual to obtain the total thermal resistance Rth (difference between the cell and the ambient
temperature to the available irradiance on the cell) from experimental measurements. It has been realized an
experimental apparatus with the aim of reproducing the thermal load conditions on a concentrator photovoltaic cell. By
studying and comparing the thermal behaviours of various solutions, it is possible to come to the comprehension of the
thermal phenomenon, so allowing the choice and the configuration of the best structure from the point of view of the
performances/cost ratio.
Keywords: Concentrator Cells, Thermal Performance, Experimental Methods
| Pubblicazioni/2005/DissipazioneTermica.pdf |
R. Fucci, G. Leanza, F. Pascarella, A. Romano, F. Roca
ENEA Research Center Portici – Località Granatello 80055 – Naples – Italy,
email:fucci@portici.enea.it
| 324KB |
| 20/05/2005 0.00.00 |
IN SITU CONDUCTED EMISSSIONS ON THE GRID CONNECTED PV-SYSTEMS
|
The paper presents the levels of conducted emissions, measured at the AC side terminals of a large grid connected photovoltaic plant, in pre-compliance regime. The conducted emissions - also named voltage noises - are voltages, present on the connection cables, with frequencies in the order of radio frequency. They are related to circulating currents - said noises currents or radio currents (IRF) - that can give electro magnetic interference when they appear on cables or structures with determined amplitudes. Using two different approaches the measurements have been made: one with the LISN, reading directly the conducted voltage stated by the standard and the other with the addition of a current probe at radio frequency. The conducted noises data are then compared to the limits of the standard CEI EN55014 for electric devices with more than 1000W of power. The survey was made within the general activity of ENEA for Photovoltaic System characterization.
Keywords: 1) Large grid-connected PV-systems 2) EMC 3) In situ conducted measurements
| Pubblicazioni/2005/Emissioni.pdf |
G. Graditi, A. Matano, M. Pellegrino, R. Schioppo-
ENEA Centro Ricerche, Località Granatello - 80055 Portici (NA), Italy, email to matano@portici.enea.it
ENEA Centro Ricerche Area Sperimentale di Monteaquilone (FG), Italy
| 246KB |
| 18/05/2005 0.00.00 |
RENOVATION OF SOCIAL HOUSES: A GOOD OPPORTUNITY FOR BUILDING INTEGRATED PV SYSTEMS
|
The field of the building renovation represents at the moment one of the more interesting opportunity for the
diffusion of BIPV, especially in countries like Italy where an huge heritage of buildings exists. A preliminary distinction has
to be made between valuable buildings and standard or poor buildings, also referring to the different kinds of appropriate
project approaches.
The present work is focused on non valuable buildings, and particularly on the residential ones for the not-too-well-off
people, called “social houses”, that are characterized by a rather poor technology and quality of the coverings (roof and
especially facades). Generally interventions on the coverings are required in order to improve the energy performance of the
envelopes and the comfort and satisfaction of the inhabitants.
The project approach of the study is considering the PV systems not only as energy generators, but above all as an element of
the general façade composition. So, the integration of photovoltaic devices in existing social houses is an excellent chance to
reach a good appearance allowing a better satisfaction of the inhabitants, which is one of the more relevant aspects in
planning social houses.
Keywords: building integration: BIPV in renovation; BIPV aesthetic appeal; PV sun-shading devices.
| Pubblicazioni/2005/Facciata 6CV.2.17.pdf |
A. Scognamiglio1, G. Graditi1, P. Bosisio2, L. Pereira2
mail to: alessandra.scognamiglio@portici.enea.it; tel. +39 081 7723304; fax +39 081 7723344
1ENEA, C.R. Portici, località Granatello, 80055 Portici (NA), Italy
2DIPARC, Università degli Studi di Genova; Stradone S. Agostino 37, 16123 Genova, Italy
| 897KB |
| 16/05/2005 0.00.00 |
THE PhoCUS STANDARD UNIT: DESIGN. REALIZATION AND PRELIMINARY PERFORMANCE ANALYSIS
|
The PhoCUS (Photovoltaic Concentrators to Utility Scale) project was launched by ENEA (Italian Agency
for the New Technologies, Energy, and Environment) in the late 2001 to develop, in close cooperation with national
industrial operators, a low-cost photovoltaic concentrators technology. The road-map was outlined to get in short-medium
term a system cost of 4.1€/Wp with a production of 5MW/year by assuming 20% as module nominal efficiency and 9% the
incidence of the cell on the whole system cost. The design criteria of the standard unit, based on the applications of medium
concentration refractive optics, permits to work singularly in connection with the low voltage grid and to be parallel
connected each to other for a centralized power generation, The size was fixed at 5 kW in order to meet a distributed
generation market demand and to limit the PV generator area to a single medium size tracking structure. Each PV C-system
component was developed to assure opportunities be easy transferred to the production. The first standard unit prototype was
installed in the first months of this year at Portici ENEA Research Center and the setting up and acceptance phase are in
progress. The paper reports the lesson learned by the design, realization and installation of the system.
Keywords: concentrators, PV module, PV system
| Pubblicazioni/2005/ImpiantoPhocusSU.pdf |
A. Sarno*, F.Apicella, C.Cancro, R. Fucci, F.Pascarella, M.Pellegrino, C.Privato and F. Roca
Enea Portici Research Center Loc.Granatello 80055 Portici (Napoli) - Italy
* phone +39 081 77 23 202 e-mail: sarno@ portici.enea.it
| 1.1MB |
| 15/05/2005 0.00.00 |
A-SI THIN FILM MODULES: OPERATIONAL EXPERIENCE AND PERFORMANCE DEPENDENCY ON PV TECHNOLOGY AND ENVIRONMENT
|
The paper presents preliminary performance data of roof integrated a-Si thin film modules that have been installed at a by-the-sea facility in Mediterranean climate for testing their behavior in aggressive climatic conditions. The annual energy production has been used for the survey since it is the most useful indicator of performance in real operating conditions, in addition of providing the basis for the photovoltaic system design. The experiment aimed to look at the main barriers for a-Si thin film technologies and to provide a better understanding. The project was planned to evaluate the reliability of the modules efficiency in terms of capacity to maintains the energy conversion efficiency over long periods and the behaviour of the modules structures subjected to the hard marine environment conditions (temperature, corrosion etc.). An accurate monitoring system of the environmental parameters and of the generated power has been used to evaluate the effects of the primary factors. Data collected after a few years of continuous monitoring are shown.
Keywords: Degradation, a-Si, Performance, Environmental Effect
| Pubblicazioni/2005/KANEKA.pdf |
F. Apicella1, V. Giglio1, M. Pellegrino1, S. Ferlito1, G. Flaminio1, Y. Okamoto2, F. Tanikawa2
1 Centro Ricerche ENEA - Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile.
Loc. Granatello - 80055 Portici (NA) - Italy
Tel.+390817723400; Fax+390817723344; e-mail: felice.apicella@portici.enea.it
2 Kaneka Corporation - Osaka, 530-8288, Japan
| 171KB |
| 14/05/2005 0.00.00 |
DESIGN, REALIZATION AND PRELIMINARY PERFORMANCE ANALYSIS OF
THE PhoCUS -5 STANDARD UNIT
|
The main scope of PhoCUS (Photovoltaic Concentrators
to Utility Scale), launched by ENEA (Italian Agency for
Energy, New technologies and Environment) and partially
supported by the Italian University and Research Ministery
(MIUR) is to develop, in close cooperation with industrial
operators, a low-cost photovoltaic concentrators technology
(C-technology) to be applied in Mediterranean climates, like
Southern Italy. The road-map of the project was outlined to
get in medium term a system cost of 4.1€/Wp with a
production of 5MW/year and assuming 20% as module
nominal efficiency and 9% the incidence of the cell on the
whole system cost. One of the main objectives of the
PhoCUS is the development, the design and the realization of
the standard unit based on a medium concentration factor to
be achieved by means of refractive lenses able to be
integrated into the PV module. The installation of the
standard unit first prototype at Portici ENEA Research
Center was completed in the first months of this year. At
present, the setting up and acceptance phase are in
progress.The paper will report the lesson learned by the
design, realization and installation of the system. The results
coming from specific experimental campaigns both on single
component and on whole system will be presented and
discussed
Keywords: concentrators, supporting structure, PV module
| Pubblicazioni/2005/PhocusArizona.pdf |
A. Sarno*, F. Apicella, C.Cancro, R.Fucci, M.Pellegrino, C.Privato, F.Roca
Enea Portici Research Center Loc.Granatello 80055 Portici (Napoli) - Italy
* phone +39 081 77 23 202 e-mail: sarno@ portici.enea.it
| 243KB |
| 13/05/2005 0.00.00 |
Plastic Structured Optics for Solar Concentrators in PV Systems
|
The main advantages of using plastic structured optics for
concentrating solar beams on a receiver of a PV system,
instead of more traditional materials like glass and quartz,
rely on very large mass production, improved structured
optics design and manufacturability, reduced weight, high
optical quality, low unit cost. ENEA in the framework of
PhoCUS (Photovoltaic Concentrators to Utility Scale) Project
has investigated both prismatic (patented) and multi-foci
Fresnel PMMA (polymethylmethacrylate) optics. Among all
the molding technologies, the injection process has been
selected to produce these optics. Some critical parameters of
manufacturing process have been investigated in order to
improve the aspect ratios and the optical quality of the
molded prismatic lens. The resulting samples for this type of
lens appear to have a reduced stress, satisfactory planar
surfaces and a small radius of curvature for rounded corners,
corresponding to a good optical efficiency (major than 80%).
The results obtained with the multi-foci Fresnel lens have
been less adequate. The first production of prismatic lens has
been employed to realize the PhoCUS C-module prototypes,
presently under outdoor testing. Further improvement is
expected with the deposition of an antireflective hard coating
on the incoming surface.
| Pubblicazioni/2005/PlasticStructuredOptics.pdf |
C. Privato, C. Cancro, M. Pellegrino and Angelo Sarno
ENEA Centro Ricerche
Località Granatello I-80055 Portici (NA), Italy.
e-mail: carlo.privato@portici.enea.it tel: +39-81-7723-273 fax: +39-81-7723-493
| 890KB |
| 12/05/2005 0.00.00 |
ELECTRICAL CHARACTERIZATION OF POINT FOCUS CONCENTRATOR PHOTOVOLTAIC CELLS
THROUGH INDOOR AND OUTDOOR MEASUREMENTS
|
Photovoltaic (PV) cells and modules are often rated in terms of a set of standard reporting conditions defined
by temperature, spectral irradiance, and total irradiance. As photovoltaic devices operate on a wide range of temperatures
and irradiances, the temperature and irradiance –related behaviour must be known. The use of flash solar simulators allows
the characterization of any kind of receivers; the energy that the cell receives during the measurements is negligible and it
doesn’t change the value of the temperature appreciably. But concentration level and lack of uniformity affect the various
working variables (Voc, Iscc, η, FF) in such a way that is not the same for all cells and lenses; to evaluate the real space
distribution effect of the luminous energy on the characteristics of the cell, an experimental apparatus for outdoor
measurements has been realized, and a series of measurement techniques has been executed on the cell in order to evaluate
the performances of a PV-C cell.
Keywords: Concentrator Cells, Characterization, Experimental Methods
| Pubblicazioni/2005/CaratterizzazioniElettriche.pdf |
R. Fucci, G. Flaminio, G. Leanza, A. Romano, F. Roca
ENEA Research Center Portici
| 300KB |
| 12/05/2005 0.00.00 |
RADIOMETER FOR CONCENTRATED SOLAR RADIATION
|
We describe a novel radiometric method and apparatus,
suitable for both total power and spatial intensity profile measurement
of concentrated solar radiation.
The radiation is collected by a first optical cavity,
where it is integrated and attenuated.
A portion of this radiation is driven,
through a window with selected aperture area,
to a second optical cavity where it is integrated and
attenuated for the second time.
In the second cavity the solar radiation intensity is
measured using a conventional low flux density radiometer
and spectrally analyzed using a conventional spectrometer.
The proper selection of the intermediate window aperture allows
the level of radiation intensity at the input to be regulated and
very high levels of attenuation can be obtained, in the order of thousands.
When used for intensity profile measurements, the radiometer is moved by
an x-y translation stage to draw the 2D map of intensity.
| Pubblicazioni/2005/Radiometro.pdf |
A. Parretta*1, M. Pellegrino1, G. Flaminio1, S. Bolognesi1, G. Nenna1
1ENEA Research Centre, Località Granatello, 80055 Portici (Na), Italy.
*Phone: +39 (0)81 7723262; Fax: +39 (0)81 7723344; E-mail: antonio.parretta@portici.enea.it
| 253KB |
| 11/05/2005 0.00.00 |
REFLECTANCE AND TRANSMITTANCE INDOOR TECHNIQUES
FOR TESTING CONCENTRATING LENSES
|
The technical and economical success of the concentrating PV systems relies, beyond other important
primary factors as cells efficiency, tracking precision and module assembly quality, also on the device good optical
performance for efficiently directing solar rays on the receiver. In fact the proper lens should meet many different
requirements: it has to be very well designed and realized, made of a material with high optical grade properties and
cheap, good to withstand the environmental causes of degradation and durable. ENEA launched the PhoCUS
(Photovoltaic Concentrators to Utility Scale) Project in the late 2001 for medium concentration, 200X, in order to
investigate the photovoltaic concentrators technologies and to assess the technical and economical feasibility of this
application in Italy for the electrical energy generation. The cost effectiveness success of this project goes necessary
through the optical device good realization. So testing the optical efficiency of the lenses in a reliable and easy way
is crucial for making an early assessment of their quality and capability to reach the ultimate project purpose.
Keywords: Concentrators, Characterisation, Optical Losses
| Pubblicazioni/2005/Riflettanza.pdf |
M.Pellegrino, S. Bolognesi, G. Flaminio, C. Privato, A.Romano and A. Sarno
ENEA Research Centre, Località Granatello, 80055 Portici (Na), Italy.
Phone: +39 (0)81 7723262; Fax: +39 (0)81 7723344;
e-mail: michele.pellegrino@portici.enea.it
| 253KB |
| 10/05/2005 0.00.00 |
SOE AND ASSEMBLY METHODOLOGY: HOW TO REDUCE THE LOSSES AND
THE COSTS IN A CONCENTRATION MODULE
|
The Authors focus on the description of an analytical method in order to analyse the optic losses in a
concentration module and the constructive improvements to minimize its. The first part of the paper concerns a detailed
analysis about the constructive, assembling and dimensional aspects of a C-module; in particular has been analyzed the Cmodule
of PhoCUS project as a reference case [1]. The module architecture consists on: the heat sink, the cell, the housing
and the lens-parquet. The values of dimensional tolerances of the above components have been measured and the centring
tolerance of cell on the heat sink, that one of parquet on the housing has been defined.
In the second part of the paper the optic misalignment aspect has been analyzed. The displacement and the deformation of
optic spot, due to a solar tracker mistake, have been studied. The results, which are in experiments, show the optical losses
on the cell are due to the matched effects of alignment and tracking errors. Subsequently, the planning of a Secondary
Optical Element (SOE) and the constructive solutions have been described. SOE is able to deflect the luminous beams
coming from the disc on cell area with an error of tracking of +1°. Different tests, by means constructed prototypes
handicraft of SOE, have been carried out. The use of SOE gives the following benefits: decreasing of precision demanded to
the solar tracker, protection of plastic housing from dangerous outside fire, reduction of the intrinsic losses in the case of
non-optimal tracking, uniformity of energy flux over the cell [2] and a small decrease of the system global cost.
KEYWORDS: Concentrators, optical losses, economical analysis.
| Pubblicazioni/2005/SOEmethodology.pdf |
C. Cancro, R. Fucci, G. Graditi, C. Privato, F. Roca, A. Romano, A. Sarno
ENEA Centro Ricerche, Località Granatello - 80055 Portici (NA), Italy
tel:+390817723111; fax:+390817723344
email: carmine.cancro@portici.enea.it
| 253KB |
| 09/05/2005 0.00.00 |
DESIGN OF VERTICAL SUNSHADING PV SYSTEMS FOCUSED ON PHOTOVOLTAIC
|
The main focus of the authors is on providing architects, planners and designers with an easy tool allowing a
preliminary design of fixed photovoltaic sun-shading devices. The approach is formulating some criteria focused on
photovoltaic performance, but some preliminary conditions have been established in order to evaluate only the possibilities
representing a good balance between the different functions (sun-shading and photovoltaic generator). Particularly a
conceptual model of a vertical PV sun-shading system has been designed so that on June 21 (maximum annual Sun elevation)
it matches two conditions: the shading effects over the lamellas are avoided, and the interior is well shadowed by the
sunshade. In order to establish the minimum respective distance between lamellas (pitch) a mathematical relation depending
on the geographical site (latitude) has been determined; it links all the different parameters that have to be considered during
the design process. Various alternatives have been analysed referring to a fixed South-oriented façade and changing
parameters like: latitude, lamellas width, pitch and tilt, sunshade tilt and distance from the facade. The results have been
collected into some abacus, and the electrical performances of the different cases have been predicted using a simulation
code, and then evaluated by means of appropriate factors.
Keywords: building integration, PV sun-shading device
| Pubblicazioni/2005/Sunshading.pdf |
A. Scognamiglio1, G. Graditi1, P. Bosisio2, E. A. Cordasco3
mail to: alessandra.scognamiglio@portici.enea.it; tel. +39 081 7723304; fax +39 081 7723344
1ENEA C. R. Portici, Loc. Granatello - 80055 - Portici, Italy
2DIPARC, Università degli Studi di Genova, Stradone S. Agostino 37 - 16123 - Genova, Italy
3Facoltà di Ingegneria, Università Federico II, P.le Tecchio 80 - 80125 - Napoli, Italy
| 173KB |
| 08/05/2005 0.00.00 |
TOOLS FOR AN EFFICIENT POLICY OF PV IN URBAN PLANNING
|
Policy makers and administrative bodies are to prepare regional or local energy plans for their
territories. As photovoltaic energy, among other renewable sources, has a great potential to be largely and widely
used while integrating built environment and infrastructures under their jurisdictions, reliable tools should be
deployed in order to make the task easier and to get complete and detailed plans for intervention. In addition to the
land aerial photos so far largely used by municipalities for exploration and use of territory for different applications,
other than BIIPV integration, the efficient use of Geographic Information Systems - at a local, Regional, National or
even International level- maybe also using satellite data for preliminary rough estimates, may provide help for
useful and accurate analyses. Such an approach relies on already achieved results for biomass, geothermal and wind
energy potential assessment and exploitation; the paper shows a specific new Building and Infrastructures Photo
Voltaic Geographic Information System (BIIPV-GIS) tool for distributed urban scale PV sources integrated to
buildings and infrastructures, carried out on a little case-study to prove if dynamic multi-criteria above mentioned
methodology could be successfully deployed, giving same effective and useful results in terms of urban planning,
even at a larger scale.
Keywords: 1. Building and Infrastructures Integration 2 Energy Options 3Policy making
| Pubblicazioni/2005/ToolsUrban.pdf |
M. Pellegrino1, D. Gomez Gane3, L. Nibbi2, G. Tondi2
1ENEA Research Centre, Località Granatello, 80055 Portici (Na), Italy.
*Phone: +39-81-7723262, Fax: +39-81-7723344,
e-mail: michele.pellegrino@portici.enea.it
2ETA Renewable Energies, Piazza Savonarola 10 - 50132 Florence, Italy
Phone +39-055-5002174, Fax +39-055-573425,
e-mail: leonardo.nibbi@etaflorence.it, gianluca.tondi@etaflorence.it
3 La Sapienza University, Faculty of Architecture, Piazza Borghese 9- 00186 Rome, Italy
Phone: +39-06- 49918870, Fax: +39-06- 49918873
e-mail:dgomezgane@yahoo.it
| 36KB |
| 04/11/2004 0.00.00 |
Current-voltage characteristics of high-efficiency silicon solar cells from photoluminescence
|
Series resistance is a fundamental power-limiting factor for a solar cell. It is known to depend on the
ohmic losses due to the metal contact resistance, the metal–semiconductor contact resistance, the
substrate resistance, and the emitter sheet resistance. A typical operating approach consists of
indirect measurements of the total series resistance. Our method, based on photoluminescence, is
capable of generating an illuminated current–voltage curve free from the effect of the contact series
resistance, giving an immediate idea of true cell performance. © 2004 American Institute of
Physics.
| Pubblicazioni/2004/APL2.pdf |
L. Ferraioli and P. Maddalenaa)
INFM-COHERENTIA, Dipartimento di Scienze Fisiche, Università di Napoli “Federico II,” Via Cintia,
I-80126 Napoli, Italy
A. Parretta
ENEA Centro Ricerche Portici, Località Granatello, I-80055 Portici (Na), Italy
A. Wang and J. Zhao
Centre for Photovoltaic Engineering, University of New South Wales, Sydney NSW 2052, Australia
| 53KB |
| 07/10/2004 0.00.00 |
Evidence for generalized Kirchhoff’s law from angle-resolved electroluminescence of high efficiency silicon solar cells.
|
The angular distribution of infrared radiation, emitted by high efficiency single-crystalline silicon
solar cells, was analyzed. Measurements were performed on cells with planar and inverted-pyramids
surfaces, both showing integral emissions that approach the cosine function in the 0°–90° interval.
Textured cell maintains the cosine distribution at the different wavelengths; planar device shows a
distribution, which deviates from the cosine function at increasing wavelength. Correspondence
between emission and absorption properties was demonstrated valid as a function of emission/
absorption angle. From the angular distribution of electroluminescence light, the devices absorption
properties for incident light with directions different from the surface normal were estimated.
| Pubblicazioni/2004/APL02484.pdf |
L. Ferraioli and P. Maddalenaa)
INFM-COHERENTIA, Dipartimento di Scienze Fisiche, Università di Napoli “Federico II,” Via Cintia,
I-80126 Napoli, Italy
E. Massera and A. Parretta
ENEA Centro Ricerche Portici, Località Granatello, I-80055 Portici (Na), Italy
M. A. Green
Centre for Third Generation Photovoltaics, University of New South Wales, Sydney NSW 2052, Australia
A. Wang and J. Zhao
Centre for Photovoltaic Engineering, University of New South Wales, Sydney NSW 2052, Australia
| 55KB |
| 07/10/2004 0.00.00 |
Optical degradation of long-term, field-aged c-Si
photovoltaic modules
|
The optical degradation induced by long-term (about 15 years) field exposure on c-Si
photovoltaic modules belonging to the large-scale Delphos ENEA PV plant, located in
Manfredonia (South of Italy), was investigated by making comparative reflectance
measurements on the exposed modules, after their dismounting and cleaning, and on the
original, unexposed counterparts. Four types of module fabrication technologies were
analyzed: Helios single-Si, Pragma single-Si, Pragma multi-Si and Ansaldo multi-Si. Siemens
multi-Si modules, of recent technology and exposed for 5 years, were taken as reference. The
electrical loss measured for the single PV generators of the Delphos plant, each corresponding
to a particular module technology, after a monitoring period of about 10 years, resulted to
range between 11–22% for the output power and 9–14% for the output current. The aging
effects on the dismounted and cleaned modules appeared as the discoloration of ARC layer,
particularly at the center of the cells, and as the formation of stains distributed over the cell
surface, likely due to the browning of the EVA. The spectral measurements of the total
hemispherical reflectance, carried out under direct light at near-normal incidence, showed that
the discoloration of ARC is associated to a decrease of the reflectance in the blue region
(400–500 nm), and a resulting levelling of the spectral reflectance curves. The spectrally
integrated measurements of reflectance carried out at diffuse white light, on the other hand,
have provided evidence of an increase of the total hemispherical reflectance for exposed
modules, particularly marked for the multi-Si modules, which correlates quite well with the
extent of current loss measured on the single PV generators of Delphos plant.
| Pubblicazioni/2004/SOLMAT3420.pdf |
Antonio Parrettaa, Mariano Bombacea, Giorgio Graditia,
Riccardo Schioppob
| 563KB |
| 29/09/2004 0.00.00 |
AMORPHOUS/CRYSTALLINE SILICON HETEROSTRUCTURE SOLAR CELL:
SIMULATION AND EXPERIMENT
|
In this work we report on the technological steps of the process we used to obtain high efficiency
heterostructure solar cell. The device is based on a cast production p-type monocrystalline silicon and on a n-type
amorphous silicon deposited by PECVD technique. An ad-hoc treatment has been performed on the top of the n layer
in order to increase the built-in voltage of the structure. This increase leads to a better collection of photogenerated
carries at the maximum power point of the cell. A numerical device simulator has been utilized to explain the
increase of device performances. Photovoltaic efficiency equal to 17% is obtained on a 2.25 cm2 total area device.
This represents the highest value in heterojunction solar cell based on p-type crystalline silicon.
Keywords: a-Si; Heterojunction; Solar Cell Efficiencies;
| Pubblicazioni/2004/ParigiHJ.PDF |
G. de Cesare1, D. Caputo1, M. Tucci2
1 Electronic Engineering Dpt, University of Rome "La Sapienza", via Eudossiana 18, 00194 Roma, Italy
2 Enea Research Center Portici, località Granatello, 80055 Portici, Napoli, Italy
| 204KB |
| 29/09/2004 0.00.00 |
MPPT CIRCUIT FOR PV SYSTEM FOR LOW POWER PORTABLE APPLICATIONS
|
In this work we have designed, fabricated and tested a Maximum Power Point Tracking (MPPT) circuit for photovoltaic systems suitable for low power, portable applications with resistive load. This type of load allows to simplify the design of the MPPT system, satisfying the specifications of low-cost, small size and low power consumption required by this application. The operation principle was proven simulating the circuit at block level by using Simulink. A photovoltaic system with and without the proposed MPPT circuit was tested on a 2 Ω resistor as well as on a camping refrigerator.
Keywords: Stand-alone PV-system, tracking, MPPT
| Pubblicazioni/2004/ParigiMPPT.pdf |
G. de Cesare, D. Caputo, A. Nascetti, M. Tucci*
Department of Electronic Engineering, University of Rome “La Sapienza”
via Eudossiana, 18 - 00184 Rome (Italy)
*ENEA Research Center
via Vecchio Macello, Località Granatello, Portici, Naples, (Italy)
| 261KB |
| 01/07/2004 0.00.00 |
PROTON INDUCED DAMAGE OF AMORPHOUS/CRYSTALLINE SILICON
HETEROJUNCTION SOLAR CELLS
|
Current-voltage under illumination and quantum yield characteristics of an amorphous
silicon/crystalline silicon hetero solar cell have been measured before and after exposure to high energy (1.7MeV)
protons. A comparison of the measured wavelength dependent quantum yield with calculated values enabled to
determine the effective electron diffusion length of the crystalline silicon, that dropped from a value of 434mm before
to a value of 4mm after irradiation with 5.1012cm-2 protons. Good agreement has been obtained between measured
and simulated data using, DIFFIN, a finite element simulation program for a-Si:H / c-Si heterojunctions solar cells,
enabling us to extract the depth profile of the recombination rate and the density of states distribution in the
semiconductor layers before and after irradiation.
Keywords: Heterojunction, Lifetime, Radiation Damage
| Pubblicazioni/2004/Parigi8AV34.pdf |
Heinz-Christoph Neitzert 1, Francesco Roca 2, Patrizio Spinillo 1, Mario Tucci 2
1 DIIIE, Università di Salerno, Fisciano (SA), Italy
Tel: +39-089-964304, fax: +39-089-964218, e-mail: neitzert@unisa.it
2 Centro Ricerche Portici, ENEA, Portici (NA), Italy
Tel: +39-081-7723270, fax: +39-081- 7723344, e-mail: roca@portici.enea.it
| 251KB |
| 29/06/2004 0.00.00 |
AN EXPERIMENTAL ANALYSIS OF POWER QUALITY IN PRESENCE OF SINGLE PHASE GRID
CONNECTED PHOTOVOLTAIC SYSTEMS
|
In this paper an experimental power quality analysis in presence of single phase grid connected PV
systems is performed in a PV system installed at the Department of Electric Engineering of the University of
Palermo through a measurement system set up by the Authors. In particular the analysis has been carried out
focusing the attention on voltage and current distortion, as the solar radiation varies. The corresponding Total
Harmonic Distortions in voltage and current terms are reported and compared with the standards limits. The presence
of interharmonic components is also discussed.
Keywords: Small Grid-connected PV Systems, Inverter, Power Quality.
| Pubblicazioni/2004/Parigi5BO96.pdf |
G. Graditi(1,2), S. Favuzza(2), E. Riva Sanseverino(2), G. Vitale(3)
(1) Centro Ricerche ENEA - Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA). Via Vecchio Macello –
80055 Portici (Napoli) – ItaliaTel.+390817723400; Fax+390817723344; email: giorgio.graditi@portici.enea.it
(2) Dipartimento di Ingegneria Elettrica – Università di Palermo Viale delle Scienze – 90128 Palermo (Italia)
Tel.+390916615221; Fax+39091488452; email: favuzza,eriva@diepa.unipa.it
(3) ISSIA (Istituto sui Sistemi Intelligenti per l’Automazione) – CNR, Sezione di Palermo Viale delle Scienze – 90128
Palermo (Italia), Tel.+39091484686; Fax+39091485555, email: vitale@cerisep.pa.cnr.it
| 295KB |
| 29/06/2004 0.00.00 |
EXCIMER LASER INDUCED CRYSTALLISATION OF HYDROGENATED AMORPHOUS SILICON-CARBON FILMS
|
Excimer laser treatments have been carried out on hydrogenated amorphous silicon-carbon with carbon content, x = C/(C+Si), in the 0.08-0.28 range varying the fluence from 64 to 242 mJ/cm2. Silicon crystallites have been induced in the samples independently of the alloy composition, while SiC crystallites have been detected in samples with x ≥ 0.18 irradiated at fluences greater or equal than to 188 mJ/cm2. The crystalline volume fraction increases as a function of carbon content in the films. After laser irradiation all the films have shown a noticeable increase in dark conductivity, and a considerable modification of the optical properties. The effects of laser annealing on the crystallisation process appear to be correlated with the optical properties of the as deposited films.
Keywords: Laser processing– 1: crystallisation –2: Silicon Carbon alloys- 3.
| Pubblicazioni/2004/Parigi3DV142.PDF |
U. Coscia1, G. Ambrosone1, C. Minarini2, V. Parisi3, S. Schutzmann4, A. Tebano5, P. Rava6, C. Privato2, P. Delli Veneri2
1INFM-Dipartimento di Scienze Fisiche, Complesso Universitario di Monte S. Angelo, via Cintia, I-80126 Napoli, Italy
2ENEA Research Center – Loc. Granatello, I-80055 Portici, Napoli, Italy
3INFM-Dipartimento di Medicina Sperimentale e Patologia, Università di Roma “La Sapienza” I-00161 Roma, Italy
4INFM-Dipartimento di Scienze e Tecnologie Fisiche ed Energetiche, Università di Roma “Tor Vergata”, Via di Tor Vergata 110, I-00133 Roma.
5INFM-Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma “Tor Vergata”, Via della Ricerca Scientifica 1, I-00133 Roma
6Elettrorava Spa, 10040 Savonera, Torino
| 251KB |
| 29/06/2004 0.00.00 |
EFFECTS OF BIPV ON PERFORMANCES
|
The effect on performances of both module temperature and non optimal array exposure will be
analysed. In this paper the five investigated grid connected PV systems are installed or integrated in buildings
(mainly Municipalities, Universities, Secondary Schools) at different geographical location and are representative of
the basic ways of mounting: namely roof, facades, canopy sunshade and free standing on flat roof.
A special emphasis has the localization of modules, characterized by high visibility for people and an educative value
for students. Of course, in order to analyze plant performance and to verify the effectiveness of the adopted technical
solutions, all the pilot plants have been routinely monitored.
The results of the analysis confirm the importance of the optimal mounting exposition as well as best solutions for an
efficient cooling of the PV modules.
Keywords: Building Integration, Performance, Evaluation
| Pubblicazioni/2004/Parigi5BV222.pdf |
A. De Lillo, Saverio Li Causi, Salvatore Castello, Francesco De Lia,
Giorgio Graditi*, Alessandra Scognamiglio*
ENEA C.R. Casaccia, Via Anguillarese 301 - 00060 - Rome, Italy
* ENEA Portici, Loc. Granatello – 80055 - Portici, Italy
| 482KB |
| 29/06/2004 0.00.00 |
TECHNICAL AND ECONOMICAL ASPECTS ON INTEGRATED PV-UPS SYSTEMS
|
This paper shows a technical-economical analysis of a novel Uninterruptible Power Systems (UPS)
configuration, in which the backup batteries would be replaced by a photovoltaic (PV) system. Many interesting
technical and economical issues concerning the proposed configuration are discussed against the traditional UPS and
backup batteries solution. Moreover the technical solutions concerning the proposed integrated system realized using
a double conversion UPS are motivated. Finally the operating costs of the proposed integrated PV-UPS system and
the classical system with UPS and batteries with different sizes, and as the back-up time varies, are also compared
and interesting results have been observed. Of course, the costs estimation for systems including renewables is not
easy and cannot be precise, especially on the mid and long term, but still the analysis carried out shows that the
proposed system seems to be an economically convenient choice at present in many cases and in the near future
almost in all cases.
Keywords: Economic Analysis, Batteries, Integrated PV-UPS Systems.
| Pubblicazioni/2004/Parigi5BV241.pdf |
G. Graditi1,2, F. Apicella1, A. Augugliaro2, L. Dusonchet2, S. Favuzza2, E. Riva Sanseverino2
1 Centro Ricerche ENEA - Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA).
Via Vecchio Macello - Località Granatello - 80055 Portici (Napoli) - Italia
Tel.+390817723400; Fax+390817723344; email:giorgio.graditi@portici.enea.it
2 Dipartimento di Ingegneria Elettrica - Università di Palermo
Viale delle Scienze - 90128 Palermo (Italia)
Tel.+390916615221; Fax+39091488452; email: augugliaro,dusonchet,favuzza,graditi,eriva@diepa.unipa.it
| 132KB |
| 29/06/2004 0.00.00 |
POWER CONDITIONING: EXPERIMENTAL TESTS TO COMPARE DIFFERENT PV - GRID INTERFACES
|
The paper focuses on a comparison among grid-connected inverters with different sizes, technologies
and PV system layouts. The comparison is based on experimental tests, where the input powers are normalised with
respect to the nominal values, in order to determine a set of meaningful parameters both in laboratory and in field
operation. The inverters under study in laboratory include one centralised inverter, one string inverter which has three
separated MPPT, one per string, and two module integrated inverters. About the PV systems in field operation, four
plants have been analysed, three with 20 kWp and one with 16 kWp power. The experimental results show that some
specifications are not fulfilled, particularly those about MPPT efficiency (due to high DC ripples and ineffective MPP
algorithm) and THD of currents injected into the grid.
Keywords: 1 Experimental Methods , 2 Inverter , 3 Grid-Connected
| Pubblicazioni/2004/Parigi 5BV119.pdf |
G. Graditi(1,2), V. Cataliotti(1), R. Napoli(3), F. Spertino(3)
(1) Università di Palermo - Dipartimento di Ingegneria Elettrica
Viale delle Scienze - 90128 Palermo, Italy
Tel: +39091-6615221; fax: +39091-488452 - Email: graditi,cataliotti@diepa.unipa.it
(2) Centro Ricerche ENEA – Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA).
Via Vecchio Macello - 80055 Portici, Napoli, Italy
Tel: +39081-7723400; fax: +39081-7723344 - Email: giorgio.graditi@portici.enea.it
(3) Politecnico di Torino - Dipartimento di Ingegneria Elettrica
Corso Duca degli Abruzzi 24 - 10129 Torino, Italy
Tel: +39011-5647105; fax +39011-5647199 - Email: filippo.spertino@polito.it
| 736KB |
| 14/06/2004 0.00.00 |
SILICON HETEROJUNCTION CELLS R&D IN EUROPE
|
Europe has a leading position in the production of crystalline ingots and wafers for PV applications. The
development of a cheaper, medium-thick polycrystalline ribbon silicon or similar silicon materials is an important topic of
photovoltaic R&D. The chemical-physical properties of the predicted material involves the risk of degradation of minoritycarrier
lifetimes associated with high-temperature processes and imposes a new approach to realize the junction. The
decrease in active-layer thickness requires novel concepts for light trapping, correspondingly and the roughness of the
surface requires specific and more efficient surface treatment for passivation. The amorphous silicon (a-Si)/monocrystalline
silicon (c-Si) Heterojunction with Intrinsic Thin-layer (HITTM) solar cell developed by Sanyo Electric was applied
successfully to c-Si and offers many excellent features for the solution of the indicated issues, but the potential of Silicon
Heterojunction (SHJ) technology on thin silicon is not totally explored. This paper gives an overview about the current R&D
activities in Europe dealing with the SHJ technology as well as the perspective for short mid term application on thin silicon.
Keywords: Silicon-1: Thin Solar cells-2: Heterojunction-3.
| Pubblicazioni/2004/Parigi 3BP.1.1.pdf |
F. Roca1, J. Cárabe2 & A. Jäger-Waldau 3
1ENEA Portici Research Centre – Località Granatello-80055 Portici (Naples) Italy.
Tel: +39081 7723 270; fax:+39081-7723344; e-mail:roca@portici.enea.it
2CIEMAT DER – Avda. Complutense, 22 E-28040 Madrid. Spain
Tel: +34.913466047; fax: +34.913466037; e-mail: julio.carabe@ciemat.es
European Commission DG JRC- Via E. Fermi 1; TP 450 I.- 21020- Ispra (VA) Italy
tel: +39 0332 78-9119 Fax:+39 0332 78-9268 e-mail: arnulf.jaeger-waldau@cec.eu.int
| 985KB |
| 07/06/2004 0.00.00 |
THE FIRST PROTOTYPES OF THE PhoCUS PROJECT:
DESIGN AND PRELIMINARY PERFORMANCE ANALYSIS
|
The main purpose of the PhoCUS (Photovoltaic Concentrators to Utility Scale) project is to develop a
photovoltaic concentrators technology (C-technology) in order to demonstrate the technical feasibility of this application in
Italy and to assess its greater potentials to drive a reduction of the PV System investment cost. The road-map of the project
was outlined on the basis of a detailed feasibility study aimed at identifying the most promising technologies to get in
medium term a system cost of 4.1€/Wp with a production of 5MW/year. During the first phase of the project the efforts have
been addressed to develop and optimise the most appropriate technologies for devices and components with particular
attention to the C-module and the tracking structure. The development of the above mentioned components, as well as the
prototypes design and realization, has been performed by Enea in close cooperation with two qualified national industrial
operators, namely Eni -Tecnologie (formerly Eurosolare) and Galileo Avionica.
The paper will illustrate the technical approach and the main design criteria followed in order to meet the technical and
economical requirements. A detailed analysis, based on both experimental and computational results, shows that the
prototypes performance is in good agreement with the expected one. A preliminary economic analysis, based on the cost of
the prototyopes, at present under construction, demonstrates that the components standardization together with an
improvement of the process automation can give a significant contribute in meeting also the target cost.
Keywords: concentrators, module, tracking
| Pubblicazioni/2004/Parigi5BV147.pdf |
M. Avitabile, C.Cancro, G.Contento, R. Fucci, F.Roca , C.Privato and A. Sarno*
F.Ferrazza°, M.Zarcone°, M.Ceccherini°°
Enea Portici Research Center Loc.Granatello 80055 Portici (Napoli) - Italy
° EniTecnologie (formerly Eurosolare) Nettuno (Roma) Italy, °° Galileo Avionica Firenze Italy
* phone +39 081 77 23 202 e-mail: sarno@ portici.enea.it
| 203KB |
| 04/06/2004 0.00.00 |
INFLUENCE OF VHF PECVD MICROCRYSTALLINE SILICON PROPERTIES ON SOLAR CELL PERFORMANCES
|
Intrinsic microcrystalline silicon was deposited by Very High Frequency Plasma Enhanced Chemical
Vapor Deposition (VHF PECVD) at a frequency of 100 MHz. The substrate temperature was varied in the range 100
– 220 °C. Different gas mixtures of silane and hydrogen were utilized, while keeping the plasma power at 20 W and
the chamber pressure at 950 mTorr. The material was characterized by means of electrical and optical properties.
Different intrinsic active layers were inserted into p-i-n microcrystalline solar cells while keeping constant the
deposition parameters of the doped layers. In particular, the effects of the active layer deposition temperature and
hydrogen dilution on the spectral response of the solar cells were analyzed. A correlation was found between the
properties of the single layer and the performance of the devices. The effect of the active layer thickness was also
studied. An efficiency of 6% was reached with a Fill Factor of about 60%.
Keywords: Thin Film, Micro Crystalline Si, Spectral Response.
| Pubblicazioni/2004/Parigi3DV117.pdf |
P. Delli Veneri , L. V. Mercaldo, E. Bobeico, P. Spinillo, C. Privato
ENEA - Portici Research Center
Località Granatello, 80055 Portici (Napoli), Italy
Phone: +39 081 7723259; Fax: +39 081 7723344; e-mail address: delliveneri@portici.enea.it
| 118KB |
| 04/06/2004 0.00.00 |
SHADING EFFECT ON MPPT PERFORMANCE IN A GRID CONNECTED 20 kWp PV SYSTEM
|
Within the Italian PV roof-top Programme, a 20 kWp generator has been installed in Torino on the façade
of the company for the management of waste materials (AMIAT). Due to the façade azimuth (20° W) besides the distances
among the floors, a partial shading effect occurs during morning periods from April to September. The shading effect
determines an important decrease of the module available power. However the paper focuses on the MPPT performance of
inverters, in the mentioned shading conditions, during which experimental data have been recorded. Due to the tracking
algorithm, the MPPT efficiency decreases (also < 80%) and the DC signals have ripple with greater amplitude but frequency
lower than the typical 100 Hz value. These increased ripples (≈30%) produce an overload operation for the capacitors and
inductor of the DC-DC converter that performs the tracking. This repetitive condition can cause failure of the inverters.
Keywords: 1 Shading , 2 Tracking , 3 Inverter
| Pubblicazioni/2004/Parigi5BV122.pdf |
G. Graditi (1,2), F Spertino (3), S. Li Causi (4)
(1) ENEA - C.R. Portici - Napoli; Via Vecchio Macello - 80055 Portici, Napoli, Italy
Tel: +39081-7723400; Fax: +39081-7723344 - Email: giorgio.graditi@portici.enea.it
(2) Università di Palermo - Dipartimento di Ingegneria Elettrica
Viale delle Scienze - 90128 Palermo, Italy
Tel.+390916615221; Fax+39091488452; Email: graditi@diepa.unipa.it
(3) Politecnico di Torino - Dipartimento di Ingegneria Elettrica - Corso Duca degli Abruzzi 24 - 10129 Torino, Italy
Tel: +39011-5647105; fax +39011-5647199 - Email: filippo.spertino@polito.it
(4) ENEA - C. R. Casaccia - Roma - Via Anguillarese 301 - 00060 S. M. di Galeria, Roma, Italy
Tel: +390630484110; fax: +390630484643 - Email: licausi@casaccia.enea.it
| 612KB |
| 04/06/2004 0.00.00 |
A GLOBAL APPROACH FOR MEASURING THE CONCENTRATING PV CELLS
|
In the lack of a specific standard for concentrating cells I-V characterization and with the need to test
the electrical performance of about 7500 cells, we adopted a global approach strategy by making measurements
under different test conditions. We hoped that the understanding of the limitations for each methodology and the
comparisons of the results would have given some indications about the righteousness and accuracy of the
measurements and, once the proper technique were been set up, also information on the quality of the cells. So a
continuous solar simulator for cells and a flash solar simulator for large area PV modules, e.g. at one sun, were
considered; the required irradiance level was then reached either by drawing the test plane nearer to the lamp,
accordingly to the minus square distance law, or by using optics along the light path to focus on the receiver. The
comparison between the measurements showed slight variations, especially in terms of fill factor and efficiencies.
The paper tries to give an understanding of the different results and at the same time an indication of the pros and
cons of each methodology. We hope that this could be also useful for the in progress preparation of the standard.
Keywords: Concentrator cells, characterization
| Pubblicazioni/2004/Parigi5BV215.pdf |
M. Pellegrino, S. Bolognesi, G.Flaminio, C. Privato, A. Romano and A. Sarno
ENEA Centro Ricerche Portici
Località Granatello. P.O. Box 32,I-80055 Portici (NA), Italy.
tel:+39-81-7723-267, Fax:+39-81-7723-344
| 519KB |
| 04/06/2004 0.00.00 |
THE SKY INTO A ROOM
|
The integration of photovoltaics in the urban scale has become one of the most interesting sectors for
solar applications and one of the added functions of the Building Integrated Photovoltaics is the light control use
either as a day lighting device or as a sun screen. For that kind of application glass-glass semitransparent modules
can be used to shed a proper light inside a room. Daylight is one of the most interesting aspect of the building
architectural project, not only for the saving of electric power, but also for the visual comfort and generally for the
health effects on human being. Medical surveys showed that the day lighting gives a good attitude for people inside
a confined room letting them to feel in more harmony with the outside environment. The quality and the quantity of
the natural light should be carefully controlled in a good light project according to the final destination of the room.
Other inconvenient problems like the excessive glare, usually in wintertime, and the overheating of the room in
summertime must be addressed. According to some rules 200 lx is the suggested minimum value for not
demanding working rooms, while 20 lx could be acceptable for transit zones.
Keywords: Façade, module integration, optical properties
| Pubblicazioni/2004/Parigi6DV230.pdf |
M. Pellegrino, S. Bolognesi, L. Bonfili* , F. Fantozzi*, G.Flaminio and C. Privato)
ENEA Centro Ricerche Portici
Località Granatello. P.O. Box 32,I-80055 Portici (NA), Italy.
tel:+39-81-7723-267, Fax:+39-81-7723-344
* Ingegneria Dipartimento di Energia Pisa, Italy
| 499KB |
| 04/06/2004 0.00.00 |
DETERMINATION OF THE THERMAL PROPERTIES OF PV COMPONENT IN BUILDINGS
|
The data on thermal exchange properties of materials and structures applied on buildings are important
for compliance to defined standard, specially for the certification of the building elements and the European Union has
recently issued the directive 2002/91/CE about the energetic efficiency of the building stating the energetic certification
compulsory. This should be also valid for the Building Integrated Photovoltaics used for the for thermal insulation. The
working temperature and the thermal conductance (or conductivity) are required for a proper installation of modules.
For the temperature measurements the infrared thermal camera, traditionally used for the hot spot test, is useful for
monitoring and mapping the envelope temperatures. The thermal exchange properties depend on the sample, its size,
the operating conditions, the air flow, the humidity and so on. So the test should be made with a good control of all
those parameters and there are two complementary approaches for performing the test, one is by means of the guarded
hot box and the other is by means of the Calibrated Hot Box. For the panel conductance characterization we first
considered the standards for materials normally used in façade, and adapted them for the PV case.
Keywords: Thermal performance, qualification and testing, building integration,
| Pubblicazioni/2004/Parigi6DV231.pdf |
M. Pellegrino, S. Bolognesi, L. Bonfili* , F. Fantozzi*, G.Flaminio and C. Privato
ENEA Centro Ricerche Portici
Località Granatello. P.O. Box 32,I-80055 Portici (NA), Italy.
tel:+39-81-7723-267, Fax:+39-81-7723-344
*Università degli Studi di Pisa FAC. di INGEGNERIA - via Diotisalvi,2 56126 PISA
| 734KB |
| 14/04/2004 0.00.00 |
A Study for Optimizing the Management Strategies of a Hybrid Photovoltaic-Diesel Power Generation System
|
Abstract. In this paper the Authors, on the basis of a software
for the management of the hybrid systems, optimize the
performance of a real plant under different working conditions.
The plant under examination is called Delphos and is a solar
installation of ENEA (National Agency of Alternative Energy)
in the South of Italy.
Key words: hybrid systems, optimization
| Pubblicazioni/2004/Spagna.pdf |
M. Sylos Labini1, G. Delvecchio2, M. Guerra3, C. Lofrumento1 and F. Neri1
1 Department of Electrotechnics and Electronics - Polytechnic of Bari
Via E. Orabona 4 - 70125 Bari (Italy)
phone: +39 080 5963256, fax: +39 080 5963410, e-mail: sylos@poliba.it
2 Technical Area - University of Bari
Piazza Umberto I n.1 , 70100 Bari (Italy)
phone:+39 080 5714648, fax:+39 080 5714655, e-mail: g.delvecchio@area-tecnica.uniba.it
3 ENEA – Experimental Area Monte Aquilone
SS 89 km 178+700, 71043 Manfredonia FG (Italy)
phone: +39 0884 543493, fax: +39 0884 543940, e-mail: michele.guerra@portici.enea.it
| 435KB |
| 14/04/2004 0.00.00 |
A Study for Optimizing the Management Strategies
of a Hybrid Photovoltaic-Diesel Power Generation System
|
In this paper the Authors, on the basis of a software
for the management of the hybrid systems, optimize the
performance of a real plant under different working conditions.
The plant under examination is called Delphos and is a solar
installation of ENEA (National Agency of Alternative Energy)
in the South of Italy.
Key words: hybrid systems, optimization,
| Pubblicazioni/2004/Spagna.pdf |
M. Sylos Labini1, G. Delvecchio2, M. Guerra3, C. Lofrumento1 and F. Neri1
1 Department of Electrotechnics and Electronics - Polytechnic of Bari
Via E. Orabona 4 - 70125 Bari (Italy)
phone: +39 080 5963256, fax: +39 080 5963410, e-mail: sylos@poliba.it
2 Technical Area - University of Bari
Piazza Umberto I n.1 , 70100 Bari (Italy)
phone:+39 080 5714648, fax:+39 080 5714655, e-mail: g.delvecchio@area-tecnica.uniba.it
3 ENEA – Experimental Area Monte Aquilone
SS 89 km 178+700, 71043 Manfredonia FG (Italy)
phone: +39 0884 543493, fax: +39 0884 543940, e-mail: michele.guerra@portici.enea.it
| 434KB |
| 02/04/2004 0.00.00 |
Testing of an Innovative Small Size Hybrid
PV-Fuel Generator
|
An innovative small size hybrid photovoltaic-electrical fuel generator was planned
and realized in the ENEA Monte Aquilone Test Site, located in the South of Italy, near Manfredonia (Apulia, Italy). This generator utilizes an innovative equipment, a
modular battery inverter Sunny Island made by SMA, provided with a bi-directional
converter to charge and discharge the batteries and with a new electronic switch
that defines the current operating mode:
- in current-controlled operation mode, the converter is synchronized to an
external power supply unit, that can be a public grid or an electrical generator;
- in voltage-controlled operation mode, the converter supports and controls an
optimal voltage at industrial frequency.
The Sunny Island is an equipment capable to control the battery loading and at the
same time to optimise the voltage and frequency of the bus AC on which different
electrical loads and Energy systems are connected. A simple single-phase power
supply can be arranged with one single Sunny Island and a standard battery pack. The energy systems can be selected between several generators depending on
availability: photovoltaic plants, small wind plants and fuel units.
The goal of this project is to demonstrate that the use of bidirectional converter allows to reduce the size and the cost of a PV system for island application and, at the same time, to enhance the reliability of the produced electrical power by using an additional back up electrical fuel generator.
In order to make a comparison of the management and realization costs among
several systems, the sizing of components was determined in the different cases:
classic PV system and hybrid with electrical fuel generator.
The experimental activity consists in the data acquisition and analysis of the system
working in real conditions. First results confirm the planning which promised a cost
reduction of the produced electrical kWh.
| Pubblicazioni/2004/FriburgTestingInnovativeHPV-FuelGenerat.pdf |
N. Giancaspro*(1); C. Privato**
*ENEA Area Sperimentale Monte Aquilone, S.S. Garganica 89, km 178+700;
71043 Manfredonia (FG), Italy
**ENEA R.C. Portici, Loc. Granatello; 80055 Portici (NA), Italy
(1)corresponding author: tel +39 0884 543493; e-mail giancaspro@portici.enea.it
| 1.1Mb |
| 02/04/2004 0.00.00 |
PROGRESS ON PV MODULE PROCESSING BASED ON SILICON HETEROSTRUCTURES - MOPHET
|
We report the progress to date of the MOPHET project, partly funded by the European Commission in the
V Framework Programme. The project aims to develop a technology which matches an all screen printing automated
process for the production of PV modules, with high efficiency – low thermal budget devices. This allows employing thin
film heterostructures such as μc-Si/c-Si, a-Si/c-Si, TCO/c-Si which can reach high efficiency values, and can be scaled up to
manufacturing levels [1]. The possibility of replacing the traditional p-type with n-type silicon substrates is explored, in
order to eliminate degradation effects due to B-O pairs. Results up to date include the realisation of lab scale high efficiency
cells, the realisation of mini-modules using heterostructure cells and the all-screen printed approach, and the realisation of
small quantities of high quality n-type multicrystalline and EFG ribbon silicon substrates.
Keywords: PV Module - 1: Cost Reduction - 2: Heterojunction - 3
| Pubblicazioni/2004/Parigi2DO26.pdf |
A. D’Andrea 6 I-00048 Nettuno, Italy
Tel +390698560403, E-mail francesca.ferrazza@enitecnologie.eni.it
W. Schmidt, H. v. Campe, A. Seidl
RWE Schott Solar GmbH, Alzenau, Germany
J. Cárabe and J.J. Gandía
CIEMAT, Madrid, Spain
F. Roca, M. Tucci, E. Bobeico
ENEA Portici Research Centre, Italy
A. Björseth , E. Sauar
ScanWafer AS, Glomfjord,Norway
J.E. Cotter , J.H.Guo
Centre for Photovoltaic Engineering, the University of New South Wales, Sydney 2052, New South Wales, Australia
| 1.48Mb |
| 01/04/2004 0.00.00 |
The Lighting Project By Means Of Photovoltaic Daylight
Factor
|
The use of the sun light for the lighting of confined rooms has been not only
increased but even recommended for different reasons, economic for the savings of
the energy bill and technical for the increasing the comfort by using a natural light
source with characteristics better for the people. Contemporary the Building
Integration of Photovoltaics has gradually increased due also to more favourable
subsidies and the modules could be used for daylighting as sunscreen or sun
curtain. The integration in buildings of semitransparent or translucent modules calls
for the determination of the optical transmittance in order to get the daylight factor
and so to determine the quantity of light entering through the component inside the
room. The paper shows two approaches: the first one has been used to verify a
project already realized in order to control its capability to the use and the other is
during the project phase. We followed both the approaches for the evaluation of the
comfort gain for a project realized in our centre where the south face of 11.7 m² of a
little room previously covered of glasses was replaced by means of PV modules.
Incidentally these modules were designed also for high standard architecture and
were aesthetically interesting. Since the daylight factor contains the transmittance of
the component, the determination of the transmittance modules was determined. The
daylight factor was measured at different points both at the floor level and at the
working plane, about 1 m, according to the standard. The procedure was made before
and after the installation of the PV façade. The measurements revealed that: the
average daylight factor was reduced from 18 % to 9 %, so the solar contribution to the
room illumination is not compromised, but at the same time both the glaring effects
and the summertime thermal overheating are largely reduced, making the room more
comfortable. The methodology was applied in two cases: one checking the optical
gain after a PV plant was installed at a façade and the other one on a project for a
restructuring of a building.
| Pubblicazioni/2004/FriburgoDaylight.pdf.pdf |
Michele Pellegrino, S. Bolognesi,L. Bonfili*, G. Flaminio and C. Privato
ENEA Centro Ricerche, Località Granatello. P.O. Box 32,I-80055 Portici (NA), Italy.
tel:+39-81-7723-267, Fax:+39-81-7723-344; mail to Michele.pellegrino@portici.enea.it
*thesist at ENEA
| 1,5MB |
| 01/04/2004 0.00.00 |
ELECTROMAGNETIC COMPATIBILITY FOR THE BIPV
|
PV plants could be the cause of radio frequency (RF) conducted radiated emissions,
namely electromagnetic signals, at both the levels of voltage and current, travelling
along the electric cables. The problem can be even more relevant for the Building
Integrated PhotoVoltaics BIPV applications since their closeness to the domestic
activities; preliminary measurements have been carried out for pre-compliance
purpose at the Research Centre ENEA on a small photovoltaic façade, while the plant
was being in operation, e.g. delivering power. The pre-compliance procedure is vey
important since if the conducted radiations overcame the standard values the same
levels of signals could likely be present in other parts of the electric circuit inside the
building, giving unwilling interferences with the other connected appliances. Another
kind of noise could generate because the size of the modules and the length of the
connection cables could make the plant acting as receiving antenna, so capturing
and then introducing foreigner RF electromagnetic signals inside the buildings,
mainly local broadcasting radio stations. In our survey the effects of differently
configured inverters have been analysed: in one case one by one module connected
inverters and the more traditional single inverter for a module string, in the other.
| Pubblicazioni/2004/FriburgoEmc.pdf.pdf |
Michele Pellegrino, A. Matano, C. Privato and R.Schioppo *
ENEA Centro Ricerche, Località Granatello. P.O. Box 32,I-80055 Portici (NA), Italy.
tel:+39-81-7723-267, Fax:+39-81-7723-344; mail to Michele.pellegrino@portici.enea.it
*ENEA Centro Ricerche Area Sperimentale di Monteaquilone (FG), Italy
| 101KB |
| 09/02/2004 0.00.00 |
PLASTICS STRUCTURED OPTICS
FOR SOLAR CONCENTRATING IN PV SYSTEMS
|
ENEA launched the Point Focus PhoCUS (Photovoltaic Concentrators to Utility Scale) Project in order to
investigate the photovoltaic concentrators technologies and to assess the technical and economical feasibility of this
application in Italy for electrical energy generation and two main targets in terms of efficiency and economical aspects, a
cost per kWp less than 2 € and a generation cost less than 0.10 € per kWh, were set. The injection process was selected
among all the moulding technologies since its large throughput and the very low unit cost makes it preferable for industrial
transfer and market accessibility; but since the aspect ratios and the quality of the molded parts have resulted sometimes not
being very satisfactory, we decided to begin a research on the molding injection technology aimed to optimize the process in
order to have a material as good and cheap as possible. As material, among different high optical quality plastics, the
polymethylmethacrilate, PMMA, was also considered for the manufacturing due to its superior optical
characteristics/convenience ratio.
| Pubblicazioni/2004/Parigi 5BV.2.16.pdf |
Michele Pellegrino, Carlo Privato and Angelo Sarno
*Antonio Apicella and Raffaella Aversa
ENEA Centro Ricerche, Località Granatello. Portici (NA),
*DISPAMA, Seconda Università di Napoli, Aversa (NA)
| 1.24MB |
| 04/11/2003 0.00.00 |
VHF PECVD MICROCRYSTALLINE SILICON: FROM MATERIAL TO SOLAR CELLS
|
Intrinsic microcrystalline silicon has been deposited by very high frequency plasma enhanced chemical vapor deposition technique at two different frequencies, 90 and 100 MHz. Different gas mixtures of silane and hydrogen were utilized, while keeping the substrate temperature at 220°C and the chamber pressure at 950 mTorr. In particular, the effect of plasma power has been investigated at both frequencies in the range 20 – 40 W. The material was characterized in terms of structural, electrical and optical properties. The optimised material was inserted in p-i-n solar cells. Since the properties of thin p-layers (~ 200 Å) strongly affect the solar cell performance, a particular care was directed to the structural and electrical characterization of this material. Preliminary results on the devices are presented: efficiency of about 3.8 % was reached for 1 μm thick solar cells.
Keywords: thin film silicon; microcrystalline silicon; solar cells; VHF PECVD.
| Pubblicazioni/2003/EMRSDelliveneri.pdf |
P. Delli Veneri, L. V. Mercaldo∗, C. Minarini, C. Privato
| 732KB |
| 03/11/2003 0.00.00 |
A PROJECT FOR AN ENERGY MUSEUM AT THE FOOT OF DELPHOS PV PLANT
|
A project for a solar building at the foot of Delphos (a demonstrative electrical PV system located in the South of Italy realized by ENEA in the 80’s) is at the moment worked out by ENEA together with MCA. Many people every year visit the site of Delphos; moreover by an architectonic point of view this PV plant has a particularity in its visual aspect: in fact, it was realized in one piece only, looking something like a photovoltaic shape in the ground, or like a pitch, and so it has a natural architectural vocation, and a special relation with the landscape.
It is intention of ENEA the realization of a new demonstrative and experimental Energy Museum that should be like a manifesto for the solar architecture; the aim of the project is to exploit the possibilities of the site both in terms of dissemination and scientific experimentation. A preliminary project has been developed; according to this project the building physically integrates the pitch of Delphos such as the landscape, it is an active envelope conceived in terms of awareness of the energetic processes, and with the utilization of photovoltaic innovative components and advanced strategies of microclimatic control. The building is articulated in different functions including a visitors centre and some research offices, so we can examine different themes connected to the different functions; particularly: daylighting in the offices, natural ventilation in the educational zone, and architectural integration of photovoltaic systems in the expo zone. In order to predict the thermal and energetic behaviour of the building and to verify the microclimate strategies we use a commercial tools, the TRNSYS.
| Pubblicazioni/2003/GoteborgScognamiglio.pdf |
M. Citterio(1); MCA Mario Cucinella Architects(2); C. Privato(3) and A. Scognamiglio(3)
(1)ENEA R.C. Casaccia, via Anguillarese, 301; 00060 S. Maria di Galeria (Rome), Italy
(2)MCA Mario Cucinella Architects, via G. Matteotti, 21; 40129 Bologna, Italy
(3)ENEA R.C. Portici, Loc. Granatello; 80055 Portici (Naples), Italy
Phone: +39 081 7723304; fax: +39 081 7723344; mail to: alessandra.scognamiglio@portici.enea.it
| 546KB |
| 02/11/2003 0.00.00 |
DO YOU KNOW? I AM A BUILDING SKIN WORKING
|
Employment of Photovoltaics on buildings has recently grown up in a very surprising way throughout all the world. Among different reasons, both technical and economical, there could be just another explanation that relies on a someway new concept of buildings: following this approach they are considered not only boxes devoted to keep the human activities inside, but their walls are perceived as active elements that interact significantly with the outside environment and the inside as well. In that case the building skin plays an active role and positively contribute to the improving of the building general performance. The photovoltaic modules can do that in such a silent, relentless and reliable way that one becomes even unaware of having them working at all. The drawback is that from an electrical point of view the modules exposure to the sun can not always be optimized in terms of the right tilt and azimuth angles and drops from the rated power values are to be expected. But in these cases how much of the maximum possible power can be allowed to be sacrificed and is this choice worth of that? The paper will show some preliminary results of the tests undertaken on different kinds of structural PV components, specifically designed to be integrated in the façade, in order to investigate their performance flexibility at different illumination conditions, both natural and artificial, and at various, not optimal, geometric exposures.
| Pubblicazioni/2003/GoteborgPellegrino.pdf |
Michele Pellegrino, Giovanni Flaminio, Carlo Privato and Alessandra Scognamiglio
| 650KB |
| 27/10/2003 0.00.00 |
IMPIANTI FOTOVOLTAICI: aspetti normativi
| | Pubblicazioni/2003/AEINormativa.pdf |
Giorgio Graditi, Felice Apicella,
Centro Ric. ENEA Portici - Napoli
Vincenzo Cataliotti
Università degli Studi di Palermo
| 732KB |
| 14/10/2003 0.00.00 |
Camera for recording light backscattered from textured photovoltaic samples
|
A camera for recording the intensity of light backscattered from textured
photovoltaic (PV) samples is described. It was realized by modifying a
professional folding camera, for use on an optical bench. The collimated
light from a laser source crosses the camera and impinges on the test sample.
The light backscattered by the sample exposes a punched photographic plate
placed on the front side of the camera. With a proper choice of laser light
intensity and wavelength, the optical diffusing effects produced by surface
morphology or by subsurface features of the sample can be recorded in this
way. The analysis of light diffusing characteristics of textured PV samples,
mainly based on crystalline silicon material, can be directed towards
improving their light collection capabilities. The camera can be assembled
in such a way as to record the light diffusion images produced in reflection
by both small and large samples, or those produced in transmission from
textured semitransparent materials.
Keywords: Light scattering, recording, textured silicon, photovoltaic devices
| Pubblicazioni/2003/JournalOpticsParretta.pdf |
Antonio Parretta
| 1.1MB |
| 14/10/2003 0.00.00 |
Investigation of minority carrier diffusion length in shallow junctions
by angle-resolved illumination technique
|
In this paper, we discuss a new approach to the determination of minority carrier diffusion length (Ld) on flat top surface shallow
junction devices in which photocurrent is dominated by diffusion component as in solar cells. In our method, we propose the use of a
single monochromatic light beam of appropriate wavelength, incident on the device surface at various angles. Under such
experimental conditions, the short circuit current of the device is expressed as a function of the internal spectral response and device
reflectance. Then diffusion length can be simply derived by the analysis of the experimental ratio between photocurrent measured at
various incidence angles and when light impinges the device orthogonally, as function of the incident angle. An analytical model is
proposed based on the modified absorption coefficient as a function of refractive angle and an experimental set-up for the
evaluation of minority carrier diffusion length is proposed.
# 2003 Elsevier B.V. All rights reserved.
Keywords: Diffusion length; Solar cell; Integrating sphere
| Pubblicazioni/2003/MaterialScienceEngineeringParretta.pdf |
A. Parretta *, P. Grillo, M. Tucci
| 368KB |
| 14/05/2003 0.00.00 |
SISTEMI FOTOVOLTAICI e gruppi statici di CONTINUITÀ
|
LÕintegrazione della generazione fotovoltaica
nei gruppi statici di continuità permette di abbinare
i vantaggi dellÕuso di una fonte rinnovabile alla fornitura di
un servizio elettrico con elevati standard qualitativi.
| Pubblicazioni/2003/AEIPV_UPS.pdf |
Giorgio Graditi Felice Apicella
Centro Ricerche ENEA, Portici
Vincenzo Cataliotti
Università degli Studi di Palermo
| 785KB |
| 14/05/2003 0.00.00 |
Convertitori statici di potenza negli impianti fotovoltaici
| | Pubblicazioni/2003/UTETInverter.pdf |
Giorgio Graditi, Felice Apicella
| 5.8MB |
| 09/02/2003 0.00.00 |
THE STATUS OF THE PhoCUS PROJECT: PRELIMINARY RESULTS
|
The main purpose of the PhoCUS (Photovoltaic Concentrators to Utility Scale) project is to develop a
photovoltaic concentrators technology ( PV C-technology) in order to demonstrate the technical feasibility of this
application in Italy and to assess its greater potentials to drive a reduction of the PV System investment cost. The road-map
of the project was outlined on the basis of a detailed feasibility study aimed at identifying the most promising technologies to
get in medium term a system cost of 4.1€/Wp with a production of 5MW/year.
The first phase of the project, lasting three years (2002-2004) is mainly focused on Research&Development and
Demonstration activities addressed respectivily to develop and optimise the most appropriate technologies for the solar cell,
the optical device, the module, and the solar tracker and to design and install a 5 kW standard unit.
A pilot demonstrative plant (25 kW) consisting of 5 standard units will be installed at Enea Monte Aquilone Test-Site,
located in Manfredonia (South East of Italy) for field testing both the single components and the whole system.
In the frame of the project scientific collaborations with National Universities and Research Institutions have been started as
well as two qualified industrial operators, namely Eurosolare and Galileo Avionica, are cooperating in industrial design and
realizing the prototypes of the C-module and the tracking structure. The realization of the single components, like the solar
cell assembling and the optical devices, is benefiting by a fruitful interation with International and National operators.
This paper will report the status of the differet activities ongoing and present and discuss the results so far achieved.
Keywords: concentrators, supporting structure, PV module.
| Pubblicazioni/2003/PhocusAustralia.pdf |
A. Sarno*, F. Apicella, L. Pirozzi, M.Pellegrino, C.Privato, F.Roca
Enea Portici Research Center Loc.Granatello 80055 Portici (Napoli) - Italy
Enea Casaccia Research Center Via Anguillarese 301 00060 Roma – Italy
* phone +39 081 77 23 202 e-mail: sarno@ portici.enea.it
| 311KB |
| 03/02/2003 0.00.00 |
Analysis of microcrystalline silicon absorber layer in solar cell devices
|
Microcrystalline silicon thin film solar cells has been prepared using intrinsic layer deposited by very high frequency PECVD at 100 MHz. Different gas mixtures of silane and hydrogen have been utilized, while keeping the substrate temperature at 220 °C and the chamber pressure at 950 mTorr. The effects of both plasma power and thickness of active layer were investigated with the aid of a numerical model able to describe stacked structure of semiconductor thin film. A good agreement with experimental data has been found by suitably choosing the thickness and defect density of these layers. The effect of hydrogen dilution, plasma power and active layer thichness has been investigated.
| Pubblicazioni/2003/icams.pdf |
P. delli Veneri, L.V. Mercaldo, M. Tucci
| 272KB |
| 16/11/2002 0.00.00 |
MONITORING OF INTERFACE DEFECTS IN a-Si:H/c-Si HETEROJUNCTION SOLAR CELLS
|
In this paper we analyzed amorphous crystalline silicon heterostructure for photovoltaic application. In
particular we investigated the difference and the potentiality of the two kind of heterojunctions: p-type amorphous silicon
/ n type crystalline silicon; n-type amorphous silicon / p-type crystalline silicon. With the aid of a numerical model able
to solve AC and DC problem in multiplayer structure we evaluated the transport mechanism and the defect behavior at
the junction for both kind of solar cell devices. Difference in the technological steps needed to heterostructure formation
have been considered for high efficiency solar cell. Finally an explanation of the difference in the role played by the
defect density at the heterojunction for both kind of structure has been proposed.
Keywords: 1 – heterostructure; 2 – solar cell; 3 – defect.
| Pubblicazioni/2002/RomaV115.pdf |
Mario Tucci, Francesco Roca, Giampiero de Cesare*, Fabrizio Palma*
ENEA Research Center, Località Granatello, Portici, 80055 Napoli Italy
*Electronic Engineering, University of Rome “La Sapienza”, via Eudossiana 18, I-00184 Roma, Italy,
| 157KB |
| 16/11/2002 0.00.00 |
Optical characterization of recombination parameters of bulk silicon
and crystalline/amorphous silicon interface in solar cells
|
The knowledge of silicon recombination parameters is of paramount importance in solar cells manufacturing processes because they are strictly related to the final achievable efficiency. The present work is aimed to the characterization of crystalline/amorphous silicon interfaces by means of an optical contactless technique. In particular, we used a pump-probe measurement apparatus based on the use of a modulated laser beam (pump beam, λ=0.80µm) to inject charge carriers in the solar cell and a CW pigtailed laser diode (probe beam, λ=1.55µm) to monitor the recombination process. Through the measurement of the sample frequency response it is possible to separate the bulk recombination lifetime and the surface recombination velocities by means of suitable fitting routines. Different heterojunction solar cells have been analyzed by means of the above method.
| Pubblicazioni/2002/RomaV136.pdf |
R. Bernini*, S. Campopiano**, N. Martucciello§, F. Roca§, L. Zeni**
M. Losurdo+, G. Bruno+
*CNR-IREA Via Diocleziano 328 – 80124 Napoli (Italy)
**Seconda Università di Napoli
Dipartimento di Ingegneria dell’Informazione
Via Roma 29, 81031 Aversa (Italy)
§Centro Ricerche ENEA
Località Granatello, Portici - Napoli (Italy)
+CNR-IMIP Via Orabona 4 - 70126 Bari (Italy).
| 263KB |
| 13/11/2002 0.00.00 |
THE PhoCUS PROJECT
|
The PhoCUS (Photovoltaic Concentrators to Utility Scale) Project started in the late 2001 in order to investigate the photovoltaic concentrators technologies and to assess the technical and economical feasibility of this application in Italy for electrical energy generation. The first phase of the project, lasting three years, is focused on Research, Development and Demonstration activities starting with the development and the optimisation of the most appropriate technologies for the solar cell, the optical device and the module, as well as to the best design of the BOS (Balance Of System) components with particular attention to the solar tracker. Concerning the demonstration and testing aspects, it is expected that a standard unit (5kW) will be developed by Enea in cooperation with national operators; a pilot plant (25 kW) consisting of 5 standard units will be installed in the Enea Monte Aquilone Test-Site, located in Manfredonia (South East of Italy). The PV generators of the first standard units will be composed of modules realized by arranging commercial backside-contact c-Si cells by Sunpower Corporation, optimised to a concentration ratio from 100 to 400X. The status of the project as well as the preliminary technical results will be presented and discussed.
Keywords: concentrators, supporting structure, PV module.
| Pubblicazioni/2002/RomaPhoCUS.pdf |
A.Sarno**, G.Contento, A.Mittiga*, C.Privato, F.Roca
Enea Portici Research Center Loc.Granatello 80055 Portici (Napoli) - Italy
*Enea Casaccia Research Center Via Anguillarese 301 00060 Roma – Italy
** phone +39 081 77 23 202 e-mail: sarno@ portici.enea.it
| 437KB |
| 04/11/2002 0.00.00 |
MINORITY CARRIER DIFFUSION LENGTH MEASUREMENTS
IN c-SI HOMOJUNCTIONS BY ANGLE-RESOLVED ILLUMINATION TECHNIQUE
|
In this paper we present a new approach to the determination of minority carrier diffusion length on flat top
surface shallow junction devices in which photocurrent is dominated by diffusion component, as in solar cells. In our method
we propose the use of a single monochromatic light beam, of appropriate wavelength, incident on the device surface at
various angles. Under such experimental conditions, the short-circuit current of the device is expressed as a function of the
internal spectral response and device reflectance. Then diffusion length can be simply derived by the analysis of the
experimental ratio between photocurrent measured at various incidence angles and photocurrent measured when light
impinges the device orthogonally, as function of the incident angle. An analytical model is proposed, based on the modified
absorption coefficient as a function of refractive angle, and an experimental set-up for the evaluation of minority carrier
diffusion length is proposed.
Keywords: diffusion length, solar cell, integrating sphere.
| Pubblicazioni/2002/RomaV118.pdf |
Antonio Parretta, Mario Tucci, Pietro Grillo, Pasquale Maddalena*
ENEA Centro Ricerche Portici, 80055 Portici (Na), Italy
*INFM, Dip. Scienze Fisiche, Università Federico II, 80126 Napoli, Italy
| 129KB |
| 04/11/2002 0.00.00 |
AESTHETICAL APPEAL OF BIPV OR ELECTRICAL PERFORMANCE
|
One of the key of success for the building integration of PV seems to lie on the aesthetical aspect of the PV modules. The quality image issue is not so trivial since they are just the end users that need to be convinced to accept the installation and in any case the modules have to be integrated into the overall concept within the building design. But in these cases how much of the maximum possible power can be allowed to be sacrificed for aesthetics sake and is this choice worth of that? The paper will show some preliminary results on different kinds of structural PV components specifically designed to be integrated in the façade, since in this case the aesthetical aspects vs. the electrical performances are more important. Modules specifically designed to fulfill high architectural visual standards were tested in order to investigate their performance flexibility at different illumination conditions and at various, not optimal, geometric exposures. The general behavior was evaluated under both an architectural and an engineering point of view.
Keywords: building, characterization, evaluation
| Pubblicazioni/2002/RomaV825.pdf |
Michele Pellegrino, G. Flaminio, G. Leanza, C. Privato and A. Scognamiglio
ENEA Centro Ricerche, Località Granatello. P.O. Box 32,I-80055 Portici (NA), Italy.
tel:+39-81-7723-267, Fax:+39-81-7723-344; mail to pellegrino@portici.enea.it
| 424KB |
| 24/10/2002 0.00.00 |
NEW R&D TRENDS IN EUROPE ON THIN-SILICON PHOTOVOLTAICS
|
About 99% of the solar-cell world production for PV terrestrial applications is dominated by silicon, of whose
share, about 80% corresponds to wafer technology. Experience has induced the conviction that silicon technology must keep
this predominant position for the next 10 years. Progress in wafer technology is needed in the direction of increasing
production and lowering costs of feedstock, mainly by investigating new growth processes leading to a cheaper silicon of an
acceptable quality. The development of medium-thickness polycrystalline ribbon silicon and similar silicon-based materials
is in the forefront of photovoltaic R&D. In parallel, the efforts on thin-film silicon technology must be concentrated on
enhancing material quality by improving film crystallinity and simultaneously thickness and growth rate. New approaches for
the preparation of silicon impose a convergence of two research lines traditionally separated. The European state of the art in
thin silicon for PV is analysed and described. A successful European RTD strategy imposes the collaboration of public and
private institutions both within the present Framework Programme, FP5, and even more in the coming FP6, by means of
Networks of Excellence (NoE) and Integrated projects (IP) in order to create the so called European Research Area (ERA).
Keywords: Silicon-1: Thin Solar cells-2: Heterojunction-3.
| Pubblicazioni/2002/RomaOE24.pdf |
F. Roca1 & J. Cárabe2
1ENEA Portici Research Centre – Località Granatello-80055 Portici (Naples) Italy.
Tel: +39081 7723 270; fax:+39081-7723344; e-mail:roca@portici.enea.it
2CIEMAT DER – Avda. Complutense, 22 E-28040 Madrid. Spain
Tel: +34.913466047; fax: +34.913466037; e-mail: julio.carabe@ciemat.es
| 161KB |
| 18/10/2002 0.00.00 |
OPTICAL DEGRADATION OF PHOTOVOLTAIC MODULES
|
The investigation of degradation effects produced on single-Si and multi-Si photovoltaic modules after
15 years of outdoor operation was carried out by comparing the optical reflectance of exposed modules with that of
original, unexposed counterparts. The photovoltaic modules refer to four different fabrication technologies and
belong to the 1st Section of Delphos large-scale ENEA PV plant located in Manfredonia (South of Italy). The
corresponding PV generators had shown an electrical degradation of 11–22% on output power and 9–14% on output
current, depending on the fabrication technology. The effects of ageing on the dismounted and cleaned modules
appear as an evident discolouration of the ARC layer or as formation of halos over the cell surface, and was
investigated by total integrated reflectance measurements under diffuse light and spectral reflectance measurements
(300-1100 nm interval) under direct light. Two specific apparatus, both equipped with 40-cm diameter integrating
spheres, were used. The exposed modules show an increase of reflectance under diffuse light, ~1% for single-Si cells
and ~2% for multi-Si cells, with respect to the unexposed ones. Also the spectral measurements show an increase of
reflectance, except for cells with ARC where a clear decrease in the blue region (400–500 nm) is observed. The
effect of degradation is to level the reflectance spectrum.
Keywords: PV Module, single-Si, Degradation, Optical Properties
| Pubblicazioni/2002/RomaOD92.pdf |
A. Parretta*1, G. Graditi1, M. Guerra2, R. Schioppo2, P. Maddalena3, E. Massera3
1ENEA Centro Ricerche Portici, Località Granatello, 80055 Portici (Na), Italy
2ENEA Area Sperimentale di Monte Aquilone, Manfredonia (FG), Italy
3Dip. Scienze Fisiche, Compl. Universitario Monte S. Angelo, Via Cintia, 80126 Napoli, Italy
*1Corresponding author. Phone: +39 (0)81 7723262; Fax: +39 (0)81 7723344: E-mail: parretta@portici.enea.it
| 1.58MB |
| 17/10/2002 0.00.00 |
TRANSPARENT p-TYPE CONDUCTING SrCu2O2 FILMS
FOR INNOVATIVE PHOTOVOLTAIC DEVICES
|
Transparent conductive oxides (TCO) catalysed relevant interest in photovoltaics thanks to the high electrical
conductivity coupled to optical transparency in the visible portion of the spectrum. On the other hand the materials used at
present are based on n-type conductivity (Indium Tin Oxide-ITO, Zinc Oxide-ZnO, Tin Oxide-SnO2). Aim of this work is
the low temperature deposition of p-type TCO. Thin films of copper-strontium mixed oxide have been deposited on glass and
quartz substrates varying the substrate temperature and oxygen partial pressure by using deposition techniques very diffused
in PV labs. For the first time, polycrystalline films of SrCu2O2 were obtained using e-beam evaporation in O2 atmosphere at
relatively low temperature (350 °C) with transparency of over 60 % in the visible light range and a high optical transmittance
in near-infrared region. The optical band gap of thin film was estimated to be ~ 3.12eV. Seebeck and Hall effects
measurements confirmed the p-type nature of semiconductors and a conductivity as high as 5.3x10-2 S/cm for non
intentionally doped materials was measured. Hole concentration and mobility at room temperature were 1.5x1017 cm-3 and 2.2
cm2V-1s-1, respectively. X-ray diffraction measurements revealed a polycrystalline structure of the films.
Keywords: p-type TCO (Transparent Conducting Oxides), thin films, e-beam evaporation
| Pubblicazioni/2002/RomaOC33.pdf |
E. Bobeico2, F.Varsano1, C.Minarini1, F.Roca1
1ENEA Centro Ricerche Portici, Località Granatello, 80055 Portici (Na), Italy
2Institute of Applied Physics, Academiei str.5, Chisinau, MD-2028, Republic of Moldova
phone: +39 0817723 203; fax: +39 0817723 344; e-mail: bobeico_eugenia@mail.ru
| 160KB |
| 16/10/2002 0.00.00 |
FIELD EFFECT a-Si:H SOLAR CELLS
|
In this paper we present a first realization of a Field Effect solar cell, based on the top channel
configuration. The amorphous silicon p-i-n structure was deposited by PECVD on metal and TCO substrates. Thin film
metal contact were conformed by photo-lithographic process. Reactive ion etching of the superficial n layer, in the area
not covered by the contacts, was performed to expose the intrinsic layer. PECVD silicon nitride was deposited for
passivation, finally transparent conductive oxide was deposited to form the top gate electrode.
Results showing the field effect enhancement of photocarrier collection will be presented, together with characterization
of silicon nitride passivation layer under high carrier density in the field effect channel.
Keywords: a-Si, Inversion-layer, Silicon Nitride.
| Pubblicazioni/2002/RomaOC12.pdf |
D. Caputo (1), G. De Cesare(1), F. Palma(1), G. Nobile(2), M. Tucci(2)
(1) INFM Unita’ di Roma and Dipartimento di Ingegneria Elettronica Università di Roma “La Sapienza”,
via Eudossiana 18, I-00184 Roma
(2) ENEA Centro Ricerche Fotovoltaiche, Portici I-80085 Napoli, Italy, +39 081 7723220, nobile@portici.enea.it
| 204KB |
| 15/10/2002 0.00.00 |
SPATIAL DISTRIBUTION OF EL LIGHT FROM HIGH EFFICIENCY
SILICON SOLAR CELLS
|
The angular distribution of infrared radiation emitted by Si-LEDs, realized by direct driving high efficiency
single-crystalline silicon solar cells, has been analyzed at different wavelengths in the 1000–1200 nm range and at room
temperature. Measurements were carried out at far-field conditions on devices realized with different dimensions and
different types of silicon surface texturisation. Planar and inverted-pyramids silicon surface LEDs have shown an integral
emission that approaches the cosine function in the 0°–90° interval. For the azimuth angle, a more accurate investigation
has been made by selecting wavelength and separating the front from the edge emission. As regards the front emission,
planar surface devices show a distribution which deviates from the cosine function at increasing wavelength. Textured
surface LEDs, on the contrary, maintain the cosine distribution at the different wavelengths. A sensible edge emission has
been revealed, which was investigated in detail by measurements around 90°. The well known correspondence between
emission and absorption properties, as dictated by the Kirchhoff law, has been demonstrated valid for our devices as
function of emission/absorption angle, by comparing angle-resolved emission and absorption measurements.
Keywords: c-Si, High Efficiency, Electroluminescence, Texturisation
| Pubblicazioni/2002/RomaOC51.pdf |
A. Parretta1*, L. Ferraioli1, L. Lancellotti1 and M. Tucci1
1ENEA Centro Ricerche Portici, Località Granatello, 80055 Portici (Na), Italy
*Corresponding author, Phone: +39 (0)81 7723262; Fax: +39 (0)81 7723344; E-mail: parretta@portici.enea.it
P. Maddalena2 and E. Massera2
2INFM, Dipartimento di Scienze Fisiche, Università di Napoli “Federico II”, Via Cintia, I-80126 Napoli, Italy
M.A. Green3, A. Wang4 and J. Zhao4
3Centre for Third Generation Photovoltaics, University of New South Wales, Sydney NSW 2052, Australia
4Centre for Photovoltaic Engineering, University of New South Wales, Sydney NSW 2052, Australia
| 158KB |
| 15/10/2002 0.00.00 |
ANALYSIS OF LIGHT BACKSCATTERED FROM TEXTURED SILICON SURFACES
|
Light backscattering properties of a variety of textured crystalline silicon samples were analyzed by
measuring the aspect ratio of light intensity angular distribution. Unpolarized laser beams at 543 and 633 nm, incident
orthogonally to the silicon surface, were used in the experiments. Different types of texturisation were analyzed: inverted
pyramids produced by anisotropic etching of single-Si surface, hemispherical wells, produced by isotropic etching of
single and multi-Si surface, and porous silicon, produced by electrochemical etching. Measurements of total and diffuse
reflectance, performed at the same illumination conditions, were compared with light backscattering measurements. The
correlation found between light collection properties of the textured silicon samples with the corresponding aspect ratio
and weight of the backdiffused light component is presented and discussed.
Keywords: c-Si, Porous Silicon, Texturisation, Light Backscattering
| Pubblicazioni/2002/RomaOC53.pdf |
E. Bobeico1, L. Lancellotti1, P. Morvillo1, A. Parretta*1, A. Wang2 and J. Zhao2
1ENEA Centro ricerche Portici, Località Granatello, 80055 Portici (Na), Italy.
2Centre for Photovoltaic Engineering, University of New South Wales, Sydney NSW 2052, Australia.
*Corresponding author. Phone: +39 081 7723262; Fax: +39 081 7723344; E-mail: parretta@portici.enea.it
| 120KB |
| 15/10/2002 0.00.00 |
MODELLING OF 3D-CPCs FOR CONCENTRATING PHOTOVOLTAIC SYSTEMS
|
The optical modelling of a Compound Parabolic Concentrator (CPC), to be used as photovoltaic solar light
concentrator, shows that light distribution on a circular receiver placed at its bottom is far from being uniform, as
requested for this type of application. The solution lies in the adding of a prismatic optical mixer, which breaks the
circular symmetry of the CPC, distributing light over a square surface. The optimum length of the prism for a uniform
distribution of light is twice the base. This is paid by a ~30% reduction of the original CPC concentration ratio. The CPCmixer
system has been optimized for medium levels of concentration (~100). The optical efficiency of the CPC-mixer
concentrator has been evaluated for different values of the wall reflectance, R, and a total loss of ~6% has been calculated
for a 98% reflecting silver coated wall.
| Pubblicazioni/2002/RomaOE42.pdf |
A. Parretta*1, P. Morvillo1, C. Privato1, G. Martinelli2 and R. Winston3
1ENEA Centro ricerche Portici, Località Granatello, Portici (Na), I-80055, Italy
2 Dept of Physics,University of Ferrara, Via Paradiso 12, Ferrara (FE), I-44100, Italy
3 Dept. of Physics,University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637, USA
*Corresponding author: Phone: +39 (0)81 7723262; Fax: +39 (0)81 7723344; E-mail: parretta@portici.enea.it
| 110KB |
| 04/10/2002 0.00.00 |
HYDROGEN TREATMENT IN a-Si:H/c-Si HETEROJUNCTION FOR PHOTOVOLTAIC APPLICATIONS
|
In this work we investigate the effect of hydrogen RF plasma treatments on crystalline surface of
heterojunction based on p-type textured crystalline silicon wafer and n-type film of amorphous silicon deposited by
plasma enhanced chemical vapour deposition. To qualify the interfaces we performed capacitance measurements at
different temperature in the range of 50 °K up to 300 °K and at different bias conditions using a probe signal frequency
in the range 1mHz-1MHz. Finally we measured current voltage characteristics, both in dark and under AM 1.5 condition,
to evaluate the recombination mechanism and photovoltaic parameters of devices as solar cells. A good agreement
between measured and calculated values by a suitable numerical model was obtained. We conclude that H2 plasma
treatment on p-type crystalline silicon surface produces high defect density in the region close to interface.
Keywords: Heterojunction, Dry etching, Capacitance measurements, Amorphous silicon, Solar cell.
| Pubblicazioni/2002/RomaV116.pdf |
Mario Tucci, Gaetano Contento, Nadia Martucciello, Francesco Roca, Fabrizio Palma*
ENEA Research Center, Località Granatello, Portici, 80055 Napoli Italy
*Electronic Engineering, University of Rome “La Sapienza”, via Eudossiana 18, I-00184 Roma, Italy,
| 108KB |
| 04/10/2002 0.00.00 |
RESEARCH ON Si THIN FILMS IN ENEA BY HOT-WIRE CVD
|
Amorphous and microcrystalline silicon thin films have been prepared by Hot-wire chemical vapor deposition from the decomposition of silane and hydrogen gases in a new multichamber deposition system, designed for the development of thin film solar cells. Graphite resistively heated filaments, which show less degradation than conventional filaments, have been used. Structural and electrical properties of the films have been investigated while scanning the deposition parameter space, and the homogeneity of the deposition process over the substrate area has been tested. Microcrystalline material with strong (220) orientation has been grown at appreciable deposition rate, but the electrical properties still need to be improved to obtain a device quality material.
Keywords: Thin film, Micro Crystalline Si, Rapid Growth.
| Pubblicazioni/2002/RomaV313.pdf |
Lucia V. Mercaldo*, Paola Delli Veneri, Maria Luisa Addonizio, Carla Minarini, Wu Ruihua†, Carlo Privato
ENEA - Portici Research Center
Località Granatello, 80055 Portici (NA), Italy
| 144KB |
| 04/10/2002 0.00.00 |
PROPERTIES OF LASER CRYSTALLIZED HIGHLY DOPED POLYCRYSTALLINE SILICON FILMS
|
Polycrystalline silicon thin films, 75, 90 and 300 nm thick, have been obtained by Laser Induced Crystallisation at 523 nm wavelength utilizing a Q-switched diode pumped, frequency-doubled Nd:YLF laser. Different n-doped starting amorphous materials have been deposited on glass by LPCVD technique. Irradiation energy density has been varied in order to study its influence on the material. Structural, electrical and optical properties of crystallized films have been investigated. At high energy densities, in a wide range, for the thinner samples, crystallization by laser pulses, partially overlapped, produces material with an homogeneous structure characterized by large crystallite size and high conductivity values.
Keywords: Crystallization, Laser Processing, Polycrystalline.
| Pubblicazioni/2002/RomaV325.pdf |
P. delli Veneri*, L. V. Mercaldo, C. Minarini, M. A. Nigro, A. Rubino
ENEA – Research Center
Località Granatello, 80055 Portici (NA), Italy
| 230KB |
| 04/10/2002 0.00.00 |
INTEGRATION OF PV AND UPS: ANALYSIS AND TECHNICAL EVALUATION
|
ENEA is working on a new project based on the development of new concept and innovative configurations for photovoltaic systems. The objective is to improve the system performances and to add benefits such as operational quality indices, economy and optimization design size. Two innovative configurations have been selected for study and experimental purpose. The first proposal regards the development of an inverter capable to perform both function of PV grid connected and stand alone concept. The second proposal regards a photovoltaic generator as support and integration of electrical system with conventional UPS. We have tested two types of commercial converters used, both in laboratory and in real operation, for the analysis and correlation among the different indices and variables. The investigation evaluates the technical characteristics and the better design to optimise size, performance and cost. This report presents the results of a preliminary analysis of PV experimental systems installed to the ENEA Portici Research Centre facility.
Keywords: Reliability - 1: PV-UPS - 2:
| Pubblicazioni/2002/RomaV548.pdf |
G. Graditi (1), F. Apicella, A. Scognamiglio, V. Cataliotti *
ENEA R. C. Portici, Loc. Granatello, I-80055 Portici (Na), Italy
Tel+39(81)7723111; Fax+39(81)7723344; Email: graditi@ portici.enea.it
* Università degli Studi di Palermo, Italy Tel+39(91)6566245; Fax+39(91)488452
(1)Corresponding author: Tel+39(81)7723400; Fax+39(81)7723344;
Email: graditi@portici.enea.it
| 296KB |
| 04/10/2002 0.00.00 |
Enea’s activities in building integrated
grid-connected PV systems
|
ENEA, Italian National Agency for New Technologies, Energy and Environment, is the government research institution involved in the National Photovoltaic Program, which is part of a broader Program about the diffusion of renewable energy in Italy. Within this program the ENEA’s role covers R&D and Demonstration activities as well as technical support to the Government. To promote the diffusion of the photovoltaic technology ENEA has started many activities related to the experimental and demonstrative aspects with particular attention to the Building Integrated Photovoltaic Systems (BIPV) field. Such application is considered very attractive all over the world, because of its main advantages: the electricity generation at or near the point of consumption, the possibility to replace structural elements of the building with a reduction of investment cost.
To disseminate technical and economic information and to overcome non-technical barriers, during last years a specific experimental and demonstrative programme was carried out by ENEA: small size grid-connected BIPV systems were designed and realized in many Italian localities. The systems differ for both location in the building and technological characteristics. The first operational data show that the PV systems performance ratio is around 0.70, and the inverter operating efficiency is close to the maximum value declared by the manufactures. In the present paper the three basic ways of integrating PV systems in building: roof, façade, sunshades will be presented and analyzed, by taking into account the solutions adopted on the ENEA’s systems. An accurate analysis of the performance data will allow to compare the different design criteria on the basis of operational and architectural indices. The results so far obtained, in terms of technical and economical information gathered as well as of overcoming of technical and non-technical barriers, have been creating favourable conditions both in the market and in the public opinion. That is confirmed by the success that the National and Regional Roof-Top Programmes are meeting with.
| Pubblicazioni/2002/RomaV824.pdf |
G.Graditi (1), T. Contardi, A. Sarno, A. Scognamiglio, F. Apicella
ENEA R. C. Portici, Loc. Granatello, I-80055 Portici (Na), Italy
Tel+39(81)7723111; Fax+39(81)7723344; Email: graditi@ portici.enea.it
(1)Corresponding author: Tel+39(81)7723400; Fax+39(81)7723344;
Email: graditi@portici.enea.it
| 471KB |
| 14/05/2002 0.00.00 |
THE ITALIAN PV R&D PROGRAMME: STATUS AND PERSPECTIVES
| | Pubblicazioni/2002/NewOrleans.pdf |
Italy has been active in PV related research for
about 30 years. Important results were obtained in a wide
range of subjects, and the country gained a leading position
of in terms of installed capacity and industrial production
until the mid-‘90s. However, the National PV programme
did not continue after 1996, which caused an
almost immediate drop out of dedicated resources especially
in universities, and a general reduced interest for
PV. More recently, triggered by the positive situation of
the market world-wide, and by environmental concerns
which convinced the Government through the Ministry of
Environment to launch the “PV roofs“ programme, a more
optimistic situation can be seen generally, attracting newcomers,
and inducing ENEL and Eni to expand their
commitment. There is now an expectation of an Italian
R&D programme on photovoltaics encouraged by the
Ministries of Research and Industry, which the PV community
is looking forward to.
| 39KB |