Publications, Presentations, and News Database

Thin-Film Module Reliability

Search the Thin-film Resource Database for more articles, news, and reports.

Studying and testing the reliability of thin-film modules are important steps in understanding how various module designs work and which areas need improvement to assure 30-year outdoor reliability. Understanding reliability is crucial when researchers develop or change modules.

Press Releases, Articles, Pictures/Tables/Figures, Other Items

Journal Articles

Conference Papers

Post Date	04/30/2007
Title	OUTDOOR MONITORING AND HIGH VOLTAGE BIAS TESTING OF THIN FILM PV MODULES
Link	(MS Word 64 KB)
Author	N. G. Dhere
Description	Limitations of accelerated testing to predict all possible degradation modes and mechanisms in the photovoltaic PV modules necessitate that actual outdoor monitoring and testing of PV modules be performed out-doors. For this reason, thin film PV modules from leading US thin film PV manufacturers namely, First Solar (Glass/CdTe/Glass), Shell Solar Glass/CIS/Glass), Shell Solar New (Glass/CIGS/Glass), United Solar (a-Si:H on flexible substrate), Energy Photovoltaics (Glass/a-Si:H/Glass) and Global Solar (CIS on flexible substrate) with additional one crystalline silicon module are being tested. The goal is to assess their performance in the hot and humid climate of Florida and to correlate the PV performance with the meteorological parameters namely, solar irradiance, temperature, relative humidity, wind speed, etc. Statistical data analysis of the recorded data is carried out on a daily basis and on a monthly basis with PVUSA type regression analysis. Current-voltage characteristics (I-V) of module arrays taken on a regular basis complement the results obtained with continuous data monitoring. Moreover, high voltage bias testing of the modules is carried out to study behavior of leakage currents and detect any packaging material and processing flaws and consequently the module reliability.
Venue	DOE Solar Technology Review Meeting, Denver, CO, 4/17-19/2007
Source	FLorida Solar Energy Center
Document Type	Conference Papers (Word document)
Resource Date	03/2007

Post Date	10/26/2006
Title	BOS COST SAVINGS NEEDS AND POTENTIAL FOR LARGE SCALE GROUND BASED PV SYSTEMS UNTIL 2010
Link	(PDF 495 KB) Download Acrobat Reader.
Author	M. Bachler
Description	More and more large scale ground based systems were implemented with thin-film modules in the past years in Germany. Based on module pricing thin film modules appear to be very attractive for this type of application. However there are quite significant differences in balance-of-system (BOS) costs within different c-Si and thin film (TF) module types, which have a high impact on total system costs. The BOS cost portion is significantly higher for systems with TF modules compared to c-Si modules. Existing c-Si modules and BOS components were developed and optimized to achieve cost savings in the past decades already a lot. TF modules as well as the related BOS components are at the very beginning of this development so the cost saving potential ? especially for BOS costs is considered to be significantly higher for TF module based systems. Since a 6.5% degression in the feed-in tariff is required in the German EEG for ground based systems a high cost reduction pressure is imposed on total system costs. The results of BOS cost savings achieved already will be demonstrated for a sample thin-film module.
Venue	Dresden World Conference
Source	Phonix SonnenStrom AG
Document Type	Conference Papers (Adobe Postscript file)
Resource Date	09/2006

Post Date	05/18/2006
Title	HIGH-EFFICIENCY CDTE AND CIGS THIN-FILM SOLAR CELLS: HIGHLIGHTS AND CHALLENGES
Link	(MS Word 602 KB)
Authors	R. Noufi, K. Zweibel
Description	Thin-film photovoltaic (PV) modules of CdTe and Cu(In,Ga)Se2 (CIGS) have the potential to reach cost-effective PV-generated electricity. These technologies have transitioned from the laboratory to the market place. Pilot production and first-time manufacturing are ramping up to higher capacity and enjoying a flood of venture-capital funding. CIGS solar cells and modules have achieved 19.5% and 13% efficiencies, respectively. Likewise, CdTe cells and modules have reached 16.5% and 10.2% efficiencies, respectively. Even higher efficiencies from the laboratory and from the manufacturing line are only a matter of time. Manufacturing-line yield continues to improve and is surpassing 85%. Long-term stability has been demonstrated for both technologies; however, some failures in the field have also been observed, emphasizing the critical need for understanding degradation mechanisms and packaging options. These two thin-film technologies have a common device/module structure: substrate, base electrode, absorber, junction layer, top electrode, patterning steps for monolithic integration, and encapsulation. The monolithic integration of thin-film solar cells can lead to significant manufacturing cost reduction compared to crystalline Si technology. The CdTe and CIGS modules share common structural elements. In principle, this commonality should lead to similar manufacturing cost per unit area, and thus, the module efficiency becomes the discriminating factor that determines the cost per watt. The long-term potential of the two technologies require R&D emphasis on science and engineering-based challenges to find solutions to achieve targeted cost-effective module performance, and in-field durability. Some of the challenges are common to both, e.g., in-situ process control and diagnostics, thinner absorber, understanding degradation mechanisms, protection from water vapor, and innovation in high-speed processing and module design. Other topics are specific to the technology, such as lower-cost and fast-deposition processes for CIGS, and improved back contact and voltage for CdTe devices.
Venue	WPEC4, Hawaii
Source	National Renewable Energy Laboratory
Document Type	Conference Papers (Word document)
Resource Date	05/2006

Post Date	08/25/2006
Title	POLYCRYSTALLINE THIN-FILM PHOTOVOLTAICS: FROM THE LABORATORY TO SOLAR FIELDS
Link	(PDF 682 KB) Download Acrobat Reader.
Authors	B. Von Roedern, H. S. Ullal, K. Zweibel
Description	We review the status of commercial polycrystalline thin-film solar cells and photovoltaic (PV) modules, including current and projected commercialization activities. Major technical progress has occurred in the area of thin-film PV technologies, particularly those based on cadmium telluride (CdTe) and copper indium diselenide (CuInGaSe2)
Venue	Presented at the 2006 IEEE 4th World Conference on Photovoltaic Energy Conversion (WCPEC-4) Waikoloa, Hawaii May 7?12, 2006 Conference Paper NREL/CP-520-39838 May 2006
Source	National Renewable Energy Laboratory
Document Type	Conference Papers (Adobe Postscript file)
Resource Date	05/2006

Post Date	11/17/2005
Title	OUTDOOR MONITORING AND HIGH VOLTAGE BIAS TESTING OF THIN-FILM PV MODULES
Link	(MS Word 3.2 MB)
Author	N. G. Dhere
Description	Thin-film PV modules manufactured by major US companies are being tested at the FSEC site. Monitoring of array output voltage, current, back of module temperatures, relative humidity, solar irradiance, UV irradiance and wind speed is carried outcontinuously. Plotting of power and irradiance for sunny days is now being complemented by new methods i.e. regression analysis, comparison of I-V curves for observing degradation of modules with time. Hurricane protectors were installed to ensure no major loss of data during the hurricane seasons. High voltage bias testing is being carried out to study leakage currents in individual modules. IR images are taken regularly for visual signs of degradation.
Venue	Solar Technology Review Meeting, Denver, CO, 11/7-10/2005, FSEC module reliability ("hot & humid") paper
Source	FLorida Solar Energy Center
Document Type	Conference Papers (Word document)
Resource Date	11/2005

Post Date	06/29/2005
Title	NREL PAPERS FOR THE PVSC IN ORLANDO, 2005
Link	(MS Word 41 KB)
Author	N/A
Description	Links to about 20 papers in CIS, CdTe, a-Si, thin Si and reliability.
Venue
Source	National Renewable Energy Laboratory
Document Type	Conference Papers (Word document)
Resource Date	06/2005

Post Date	02/14/2005
Title	EARLY PERFORMANCE FOR THE ROOF-MOUNTED, 20-KW THIN FILM CDTE PV-ARRAY AT JASPER
Link	(PDF 354 KB) Download Acrobat Reader.
Author	J. H. Scofield
Description	We report early performance for the grid-connected, 20-kW CdTe PV array installed on the roof of the Leslie Shao-ming Sun Field Station at the Jasper Ridge Biological Preserve. The array was installed in May 2002. Data are reported for 20-mos beginning April 2003. The array originally consisted of 275, BP Solar 80W thin-film CdTe modules arranged in 11-module strings. The monitoring system logged data from 9 sensors on 1-min intervals. Monitoring showed problems with maximum power tracking associated with module degradation, elevated module temperatures, and the finite voltage window of the 208VAC-3p inverter. The problems were addressed in May 2004 by re-wiring the array and reprogramming the inverter, resulting in a 20% increase in energy production.
Venue	IEEE PVSC
Source	Oberlin College
Document Type	Conference Papers (Adobe Postscript file)
Resource Date	01/2005

Post Date	09/27/2005
Title	DAMP HEAT STABILITY OF CHALCOPYRITE MINI-MODULES: EVALUATION OF SPECIFIC TEST STRUCTURES
Link	(PDF 77 KB) Download Acrobat Reader.
Authors	J. Klaer, et al.
Description	Damp heat stress (85% relative humidity at 85 �C) has been used to test long term stability of CIS thin film photovoltaic devices. Two CIS absorber types have been examined, CuInS2 and Cu(In,Ga)Se2. Module degradation is dominated by an increase of the series resistance Rs. In order to get information about the ZnO sheet resistance Rsq and the Mo/ZnO contact resistance Rc, which are the most important contributions to Rs, specially designed transmission-line test structures are used. Degradation of Rc strongly depends on the point of time when the second scribe for integrated series connection, P2, is made, while degradation of Rsq is strongly affected by the underlying absorber layer. Module-type solar cells without metal grid and complete mini-modules have been exposed to the same damp heat stress and yield additional information about degradation of other electrical parameters.
Venue	2005 IEEE.
Source	Hahn Meitner
Document Type	Conference Papers (Adobe Postscript file)
Resource Date	01/2005

Post Date	02/15/2005
Title	ANALYTICAL RESULTS OF OUTPUT RESTRICTION DUE TO THE VOLTAGE INCREASING OF POWER DISTRIBUTION LINE IN GRID-CONNECTED CLUSTERED PV SYSTEMS
Link	(PDF 2.4 MB) Download Acrobat Reader.
Authors	et al., Y. Ueda
Description	Output restriction to prevent over voltage of power distribution line is one of the concerns for grid-connected clustered PV systems. To investigate the behavior of clustered PV systems, "Demonstrative research on clustered PV systems" has being conducted from December, 2002 in Gunma, Japan. More than 200 residential PV systems are already installed in demonstrative research area. Operation point of array output is estimated using minutely averages of collected data. The method to quantify loss due to output restriction is developed in this study.
Venue	IEEE PVSC
Source	Tokyo University
Document Type	Conference Papers (Adobe Postscript file)
Resource Date	01/2005

Post Date	02/15/2005
Title	EARLY PERFORMANCE FOR THE ROOF-MOUNTED, 20-KW THIN FILM CDTE PV-ARRAY AT JASPER RIDGE
Link	(PDF 364 KB) Download Acrobat Reader.
Authors	et al., J. H. Scofield
Description	Here we report early performance for the grid-connected, 20-kW CdTe PV array installed on the roof of the Leslie Shao-ming Sun Field Station at the Jasper Ridge Biological Preserve. The array was installed in May 2002. Data are reported for 20-mos beginning April 2003. The array originally consisted of 275, BP Solar 80W thin-film CdTe modules arranged in 11-module strings. The monitoring system logged data from 9 sensors on 1-min intervals. Monitoring showed problems with maximum power tracking associated with module degradation, ele-vated module temperatures, and the finite voltage window of the 208VAC-3p inverter. The problems were addressed in May 2004 by re-wiring the array and reprogramming the inverter, resulting in a 20% increase in energy production.
Venue	IEEE PVSC
Source	Oberlin College
Document Type	Conference Papers (Adobe Postscript file)
Resource Date	01/2005

Post Date	02/09/2005
Title	PHYSICAL MODES OF THIN-FILM PV DEGRADATION
Link	(PDF 267 KB) Download Acrobat Reader.
Authors	et al., V. G. Karpov
Description	We discuss physical modes of degradation related to the small thickness and lack of crystallinity in thin-film PV. We discriminate between 1) uniform material degradation through defect generation, light-induced diffusion, and electro-migration; 2) nonuniform degradation through ohmic or non-ohmic shunts; 3) metal contact deterioration. The first can equally apply to bulk and thin-film PV. Two others are specific to thin-film PV.
Venue	IEEE
Source	University of Toledo
Document Type	Conference Papers (Adobe Postscript file)
Resource Date	10/2004

Post Date	02/09/2005
Title	STABILIZATION OF HIGH-EFFICIENCY CDTE PHOTOVOLTAIC MODULES IN CONTROLLED INDOOR LIGHT SOAKING
Link	(PDF 330 KB) Download Acrobat Reader.
Authors	D. Cunningham, J. A. del Cueto, J. Pruett
Description	The performance and stabilization of large-area, high-efficiency 9%, CdTe photovoltaic (PV) modules maintained under controlled light-soaking nominally at 800 Watts/m² irradiance and 65°C module temperature are investigated. Degradation of module performance occurs predominantly in the first few hundred hours of exposure under these conditions; these symptoms included losses in fill factor (FF), open-circuit voltage (V_oc), and short-circuit current (I_sc), which amount to between 7% and 15% total loss in performance. Higher stabilized performance was achieved with lower copper content in the back contact. Transient effects in module V...
Venue
Sources	BP Solar; National Renewable Energy Laboratory
Document Type	Conference Papers (Adobe Postscript file)
Resource Date	2004

Post Date	02/14/2005
Title	LONG-TERM PERFORMANCE OF THE SERF PV SYSTEMS
Link	(PDF 332 KB) Download Acrobat Reader.
Authors	J. Adelstein, B. Marion
Description	This paper provides the changes in performance ratings of two photovoltaic (PV) systems located on the roof of the Solar Energy Research Facility (SERF) building at the National Renewable Energy Laboratory (NREL) in Golden, Colorado. For the period of May 1994 to April 2002, the performance rating of the two PV systems decreased at the rate of 1% per year. Most of the changes in performance rating are attributed to changes in the performance of the PV arrays. But about a fifth of the observed changes were from the inverter not tracking the peak-power as effectively as the PV arrays aged.
Venue	NCPV and Solar Program Review Meeting 2003 NREL/CD-520-33586 Page 199
Source	National Renewable Energy Laboratory
Document Type	Conference Papers (Adobe Postscript file)
Resource Date	06/2003

Post Date	03/15/2005
Title	OVERVIEW OF AMORPHOUS SILICON (A-SI) PHOTOVOLTAIC INSTALLATIONS AT SMUD
Link	(PDF 519 KB) Download Acrobat Reader.
Author	D. E. Osborn
Description	The Sacramento Municipal Utility District (SMUD) Solar Program has installed over 10 MW of photovoltaic (PV) systems including more than 2,000 kW of amorphous silicon (a-Si), thin film PV systems installed since 1994 in systems ranging from 1 kW to 700 kW. While lower in efficiency compared to the more traditional single-crystal silicon (c-Si) and polycrystalline silicon (pc-Si) PV modules, the significantly lower price per Watt of a-Si can often result in dramatic turnkey system savings despite increased area-related installation costs. arrays at PV power stations.
Venue	ASES Solar 2003 * June 2003 * Austin, TX
Source	Spectrum Energy Corp
Document Type	Conference Papers (Adobe Postscript file)
Resource Date	06/2003

Post Date	02/14/2005
Title	ELECTROCHEMICAL CORROSION OF SNO₂:F TRANSPARENT CONDUCTING LAYERS IN THIN FILM PHOTOVOLTAIC MODULES
Link	(PDF 96 KB) Download Acrobat Reader.
Authors	J. A. del Cueto, T. J. McMahon, C. R. Osterwald
Description	We report on a degradation mechanism in thin-film photovoltaic (PV) modules activated by damp heat and voltages similar in magnitude to those generated by PV modules in power generation systems. This mechanism, which appears to be an electrochemical process involving the soda-lime glass superstrate with its conductive SnO₂:F layer, can be greatly accelerated by subjecting modules to elevated temperatures and humidity, both of which increase the leakage currents between the frame and the active PV layers. Water vapor can affect the module damage in two ways: 1) by enhancing leakage currents, and 2) by entering through the module edges, it appears to promote the chemical reaction responsible for the SnO₂ corrosion.
Venue	draft
Source	National Renewable Energy Laboratory
Document Type	Conference Papers (Adobe Postscript file)
Resource Date	2002

Post Date	03/15/2005
Title	SUPERIOR ENERGY YIELDS OF UNI-SOLAR� TRIPLE JUNCTION THIN FILM SILICON SOLAR CELLS COMPARED TO CRYSTALLINE SILICON SOLAR CELLS UNDER REAL OUTDOOR CONDITIONS IN WESTERN EUROPE
Link	(MS Word 747 KB)
Authors	et al., M. van Cleef
Description	For many years, amorphous silicon photovoltaic modules have had difficulties to establish themselves in the grid-connected PV-market. Causes for this lack of market acceptance of first generation amorphous silicon PV modules were their relatively low conversion efficiencies, unstable power and not well understood outdoor characteristics. Various manufacturers of amorphous silicon modules have resolved these initial problems by enhancing the efficiencies of their cells, while at the same time improving the long-term stability of the products. Still, the outdoor behaviour of amorphous silicon modules is not well understood by many users, even by insiders of the PV-community. Results of this study will show that new generation multi-junction amorphous silicon modules, and in particular UNI-SOLAR� modules based on the Triple Junction solar cells, perform excellent under western European climatic conditions, with yields and performance ratios significantly higher than all present crystalline silicon technologies. This effect is especially pronounced under low light conditions and under non-ideal orientations. The enhanced outdoor performance, up to 20 % higher on a yearly kWh/kWp base, can be attributed to the higher sensitivity for low light conditions and for diffuse light, better performance at high temperatures and improved shadow tolerance of UNI-SOLAR� modules.
Venue	17th EuroPV Solar Energy Conference, Munich
Source	Energy Conversion Devices
Document Type	Conference Papers (Word document)
Resource Date	10/2001

Post Date	02/14/2005
Title	MODULE 30 YEAR LIFE : WHAT DOES IT MEAN AND IS IT PREDICTABLE/ACHIEVABLE?
Link	(MS Word 68 KB)
Authors	et al., T. J. McMahon
Description	We define what we mean by a 30-year module life and the testing protocol that we believe is involved in achieving such a prediction. However, we do not believe that a universal test (or series of tests) will allow for such a prediction to be made. We can test for a lot of things, but we believe it is impossible to provide a 30-year certification for any arbitrary photovoltaic (PV) module submitted for test. We explain our belief in this paper.
Venue	IEEE
Sources	National Renewable Energy Laboratory; Sandia National Laboratory
Document Type	Conference Papers (Word document)
Resource Date	2000

Post Date	02/09/2005
Title	PROGRESS TOWARD CDTE CELL LIFE PREDICTION
Link	(PDF 1.9 MB) Download Acrobat Reader.
Authors	G. J. Jorgensen, T. J. McMahon
Description	Acclerated environmental testing.
Venue	NCPV PV Program Review 1999
Source	National Renewable Energy Laboratory
Document Type	Conference Papers (Adobe Postscript file)
Resource Date	1999

Post Date	02/14/2005
Title	SERVICE LIFETIME PREDICTION FOR ENCAPSULATED PHOTOVOLTAIC CELLS/MINIMODULES
Link	(PDF 384 KB) Download Acrobat Reader.
Authors	A. W. Czanderna, G. J. Jorgensen
Description	The overall purposes of this paper are to elucidate the crucial importance of predicting the service lifetime (SLP) for photovoltaics (PV) modules and to present an outline for developing a SLP methodology for encapsulated PV cells and minimodules. The specific objectives are (a) to illustrate the generic nature of SLP for several types of solar energy conversion or conservation devices, (b) to summarize the major durability issues concerned with these devices, (c) to justify using SLP in the triad of cost, performance, and durability instead of only durability, (d) to define and explain the seven major elements that comprise a generic SLP methodology, (e) to provide background about implementing the SLP methodology for PV cells and minimodules including the complexity of the encapsulation problems, (f) to summarize briefly the past focus of our task for improving and/or replacing ethylene vinyl acetate (EVA) as a PV pottant, and (g) to provide an outline of our present and future studies using encapsulated PV cells and minimodules for improving the encapsulation of PV cells and predicting a service lifetime for them using the SLP methodology outlined in objective (d). By using this methodology, our major conclusion is that predicting the service lifetime of PV cells and minimodules is possible.
Venue	draft
Source	National Renewable Energy Laboratory
Document Type	Conference Papers (Adobe Postscript file)
Resource Date	1997

Post Date	02/15/2005
Title	HOT SPOT SUSCEPTIBILITY AND TESTING OF PV MODULES
Link	(PDF 613 KB) Download Acrobat Reader.
Authors	K. A. Emery, E. Molenbroek, D. W. Waddington
Description	Localized heating or hot spots in a photovoltaic module can occur by any combination of cell failure, interconnection failure, partial shading, and variation in the photocurrent from cell to cell (mismatch). To probe the sensitivity for hot spot heating of commercial amorphous silicon and crystalline modules, several intrusive and nonintrusive experiments have been performed. In the intrusive experiments each cell in several commercial amorphous silicon modules was evaluated separately and in groups for localized heating effects. Damage in amorphous silicon modules occurred under reverse-bias conditions in the dark above a 5-20 mAcm^-2 cell current density at the interconnection between cells. Shading can cause a larger temperature rise than current mismatch. For the monolithic amorphous silicon modules investigated the current mismatch between each cell was substantial, but the temperature rise was negligible because of the rather low shunt resistance.
Venue	IEEE PVSC
Source	National Renewable Energy Laboratory
Document Type	Conference Papers (Adobe Postscript file)
Resource Date	1991

Presentations

Post Date	05/18/2006
Title	HIGH EFFICIENCY CDTE AND CIGS
Link	(PowerPoint 28.8 MB)
Author	R. Noufi
Description	Highlights and challenges
Venue	WCPEC4 oral
Source	National Renewable Energy Laboratory
Document Type	Presentation (Powerpoint presentation)
Resource Date	05/2006

Post Date	06/13/2006
Title	CDTE NATIONAL R&D TEAM MEETING 2006
Link	(PDF 17.3 MB) Download Acrobat Reader.
Author	H. S. Ullal
Description	The presentations from the National R&D Team meeting and Voc Workshop; Large file!
Venue	National R&D Team meeting
Source	National Renewable Energy Laboratory
Document Type	Presentation (Adobe Postscript file)
Resource Date	03/2006

Post Date	11/17/2005
Title	TECHNOLOGY IN SUPPORT OF THIN FILM CDTE PV MODULE MANUFACTURING
Link	(PowerPoint 9.6 MB)
Author	P. V. Meyers
Description	status of First Solar 2005
Venue	DOE Solar Review 2005
Source	First Solar, Toledo, OH
Document Type	Presentation (Powerpoint presentation)
Resource Date	11/2005

Post Date	11/18/2005
Title	HOT AND HUMID THIN FILM MODULE TESTING IN FLORIDA
Link	(JPG 1.2 MB)
Author	N. G. Dhere
Description	various arrays are tested
Venue	DOE Solar Review 2005 poster
Source	FLorida Solar Energy Center
Document Type	Presentation (JPG image)
Resource Date	11/2005

Post Date	11/23/2005
Title	NANOSCALE-DESIGNED CERAMIC FILMS
Link	(PDF 1.9 MB) Download Acrobat Reader.
Author	S. Sambasivan
Description	thermal barriers, conformal alumina films, epitaxial oxide growth
Venue	Nanocommerce 2004, Chicago
Source	Applied thin films
Document Type	Presentation (Adobe Postscript file)
Resource Date	10/2005

Post Date	09/02/2005
Title	PV PAST THE TIPPING POINT
Link	(PowerPoint 31.8 MB)
Author	K. Zweibel
Description	Photovoltaics is growing rapidly, coming down in cost, and technical progress is substantial. We can be assured that PV costs will come down enough to provide electricity at an energy signifiant level.
Venue	Presntation at NREL to Norwegian StudyTour sponsored by CSM August 31, 2005
Source	National Renewable Energy Laboratory
Document Type	Presentation (Powerpoint presentation)
Resource Date	08/31/2005

Post Date	07/28/2005
Title	2002 TO 2005 THIN FILM PARTNERSHIP BUDGET TRENDS
Link	(PowerPoint 38 KB)
Author	K. Zweibel
Description	Budget in thin films for subcontracts is down 36% since 2002.
Venue
Source	National Renewable Energy Laboratory
Document Type	Presentation (Powerpoint presentation)
Resource Date	07/2005

Post Date	02/07/2005
Title	2ND GENERATION THIN FILMS
Link	(PowerPoint 8.9 MB)
Author	K. Zweibel
Description	Potential of CIS, CdTe, and a-Si thin films.
Venue	Rice University Solar Energy Workshop
Source	National Renewable Energy Laboratory
Document Type	Presentation (Powerpoint presentation)
Resource Date	09/2004

Post Date	04/22/2005
Title	EPV RELIABILITY UPDATE
Link	(PDF 633 KB) Download Acrobat Reader.
Author	K. W. Jansen
Description	a-Si and CIS module designs, stress tests, and reliability
Venue	Thin Film Module Reliability Meeting
Source	Energy Photovoltaics
Document Type	Presentation (Adobe Postscript file)
Resource Date	06/24/2004

Post Date	04/22/2005
Title	UNISOLAR MODULES
Link	(PDF 2.4 MB) Download Acrobat Reader.
Author	D. E. Parker
Description	Flexible a-Si modules used for various applications
Venue	Thin Film Module Reliability National Team meeting
Source	Uni-Solar Ovonic
Document Type	Presentation (Adobe Postscript file)
Resource Date	06/23/2004

Post Date	04/22/2005
Title	LEAKAGE CURRENTS AND HIGH-VOLTAGE THIN FILM MODULES
Link	(PDF 1.1 MB) Download Acrobat Reader.
Author	N. G. Dhere
Description	FSEC testing of outdoor thin film arrays
Venue	Thin Film Module Reliability Team Meeting
Source	FLorida Solar Energy Center
Document Type	Presentation (Adobe Postscript file)
Resource Date	06/2004

Post Date	04/22/2005
Title	EFFECTS OF MOISTURE INGRESS ON PV MODULES
Link	(PDF 528 KB) Download Acrobat Reader.
Author	M. Kempe
Description	Measuring the rate water vapor moves through EVA from the edge and the back
Venue	Thin Film Module Reliability National Team Meeting
Source	National Renewable Energy Laboratory
Document Type	Presentation (Adobe Postscript file)
Resource Date	06/2004

Post Date	04/22/2005
Title	ADHESION TESTS OF CANDIDATE BACKSHEET AND ENCAPSULANTS
Link	(PDF 425 KB) Download Acrobat Reader.
Authors	J. A. del Cueto, et al., G. J. Jorgensen
Description	Pull tests of various candidate replacements for EVA
Venue	Thin film module reliability national team meeting
Source	National Renewable Energy Laboratory
Document Type	Presentation (Adobe Postscript file)
Resource Date	06/2004

Post Date	04/22/2005
Title	MOISTURE INGRESS PROTECTION BY COMBINED BACKSHEET AND ENCAPSULANT CONSTRUCTIONS
Link	(PDF 1.7 MB) Download Acrobat Reader.
Authors	G. J. Jorgensen, M. Kempe, C. Kennedy, K. Terwilliger
Description	WVTR, PET, EVA, BRP, TruSeal
Venue	Thin Film Module Reliability National Team Meeting
Source	National Renewable Energy Laboratory
Document Type	Presentation (Adobe Postscript file)
Resource Date	06/2004

Post Date	04/22/2005
Title	PAST AND PREDICTED THIN FILM MODULE PRODUCTION IN THE US BY TECHNOLOGY
Link	(PowerPoint 45 KB)
Author	K. Zweibel
Description	Annual MWp/yr 2000-2011 by technology
Venue
Source	National Renewable Energy Laboratory
Document Type	Presentation (Powerpoint presentation)
Resource Date	04/22/2004

Post Date	02/17/2005
Title	A COMPARISON OF THIN FILMS AND X-SI IN THE US MARKET, HISTORICAL AND PROJECTED
Link	(MS Word 31 KB)
Author	K. Zweibel
Description	Thin films are gaining ground on x-Si and are projected to overtake it in the US about 2010-2011.
Venue	Thin Film Partnership and Paul Maycock's PV News February 2005
Source	PV News
Document Type	Presentation (Word document)
Resource Date	02/17/2004

Post Date	02/15/2005
Title	THE INTRINSIC STABILITY OF POLYCRYSTALLINE THIN FILM SOLAR CELLS
Link	(PowerPoint 3.0 MB)
Authors	D. Albin, T. Berniard, S. Demetsu, T. J. McMahon, R. Noufi
Description	Indoor, accelerated tests of thin film CIS and CdTe
Venue
Sources	Colorado State University; National Renewable Energy Laboratory
Document Type	Presentation (Powerpoint presentation)
Resource Date	2004

Post Date	02/09/2005
Title	WHEN, WHY AND WHERE ARE CDTE/CDS SOLAR CELLS STABLE?
Link	(MS Word 960 KB)
Authors	K. D. Dobson, et al., I. Visoly-Fisher
Description	The role of Cu in CdTe/CdS solar cell instability remains the subject of much debate. The investigation of a range of 'Cu'-contacted CdTe/CdS cells, which had received various thermal stress treatments, is described. Cells that were stressed in air exhibit strong current-voltage (I-V) rollover and junction degradation. No such degradation was observed for 'Cu'-contacted cells that had been stressed in dry-N2 atmosphere. Cu is found to diffuse rapidly through the cell structure during back contact annealing and to accumulate in the CdS layer. With stress, significant levels of Cu dope the grain bulk, producing (with Cl) high resistance, photo-conducting CdS. This behavior is independent of stress atmosphere and is, therefore, unlikely to (initially) be a dominating mechanism for cell degradation. Our results suggest simple air oxidation of the back contact interface to be a likely origin of I-V rollover in CdTe/CdS cells.
Venue	CdTe Team Meeting
Source	Weizmann Institute
Document Type	Presentation (Word document)
Resource Date	2003

Post Date	02/14/2005
Title	A PHENOMENOLOGICAL APPROACH TO OBTAINING CORRELATIONS BETWEEN ACCELERATED AND OUTDOOR EXPOSURE TEST RESULTS FOR ORGANIC MATERIALS
Link	(PDF 263 KB) Download Acrobat Reader.
Author	G. J. Jorgensen
Description	Approaches are commonly used to derive correlations between in-service and accelerated exposure test results. When detailed degradation mechanisms are well understood, a deterministic formalism can be applied in which a precise damage function model is utilized. If failure mechanisms are not known or multiple mechanisms interact in a complicated manner that makes it difficult and tedious to treat them explicitly, a probabilistic procedure can be used. Observed failures are fit to appropriate life distributions to obtain expressions for related failure rates. A third approach uses a phenomenological methodology. This procedure is similar to the deterministic approach in that damage functions are hypothesized, except that they are based on macroscopic observations and effects, rather than on microscopic mechanisms. The phenomenological approach is used herein to accurately describe results from a number of highly accelerated exposure tests of organic materials. The ensuing damage function models are then used to predict real-world behavior. Excellent agreement is demonstrated between these predictions and actual measured data, thereby validating the phenomenological approach and providing a very useful way to estimate service life of organic-based materials.
Venue	draft
Source	National Renewable Energy Laboratory
Document Type	Presentation (Adobe Postscript file)
Resource Date	2003

Post Date	02/14/2005
Title	TEMPERATURE AND WATER VAPOR ENVIRONMENTS FOR THREE LOCATIONS
Link	(MS Word 345 KB)
Author	B. Marion
Description	To see how the temperature and water vapor environments for three locations compare to each other and the 85ºC/85% RH damp heat test, cumulative distribution functions (CDFs) and joint frequency tables were determined for hourly ambient dry bulb temperature, module temperature, and partial pressure of water vapor. Partial pressure of water vapor was used as a metric because it is a direct indicator of water vapor amounts, whereas relative humidity is a function of both temperature and water vapor amounts.
Venue	draft
Source	National Renewable Energy Laboratory
Document Type	Presentation (Word document)
Resource Date	07/11/2002

Annual/Final Reports

Post Date	06/02/2006
Title	DOE SOLAR ENERGY TECHNOLOGY PROGRAM FY2005 ANNUAL REPORT
Link	(PDF 5.2 MB) Download Acrobat Reader.
Author	N/A
Description	The majority of the Program?s budget is allocated to PV research and development (R&D). All PV devices convert sunlight directly into electricity. However, there is a variety of materials and processes for creating PV devices, each with its own benefits and drawbacks. The major trade-off is between cost and sunlight-to-electricity conversion efficiency?higher efficiency typically translates into higher cost. Program participants consistently achieve world-record efficiencies for different types of PV, but each effort has the same ultimate goal: optimizing cost and efficiency to produce the least expensive end-use electricity.
Venue	DOE/GO-102006-2314May 2006
Source	National Renewable Energy Laboratory
Document Type	Annual Report (Adobe Postscript file)
Resource Date	05/2006

Post Date	04/10/2006
Title	FULFILLING THE PROMISE OF THIN FILM PV
Link	(PDF 5.5 MB) Download Acrobat Reader.
Author	K. Zweibel
Description	The Thin Film PV Partnership spearheads R&D on emerging thin film PV technologies. Led by the National Center for Photovoltaics and NREL, the Partnership leverages the combined efforts of the thin film PV industry, universities, and government research institutes.
Venue	Brochure excerpt
Source	National Renewable Energy Laboratory
Document Type	Annual Report (Adobe Postscript file)
Resource Date	04/2006

Post Date	02/07/2006
Title	DOE FY2007 CONGRESSIONAL BUDGET REQUEST FOR ENERGY SUPPLY AND CONSERVATION
Link	(PDF 3.4 MB) Download Acrobat Reader.
Author	N/A
Description	Appropriation Account Summary..........................................................................................................3 Appropriation Language ........................................................................................................................7 Energy Efficiency and Renewable Energy ..........................................................................................11 Electricity Delivery & Energy Reliability .........................................................................................511 Nuclear Energy .................................................................................................................................571 Environment, Safety and Health ........................................................................................................705 Legacy Management.........................................................................................................................733
Venue	The Department of Energy?s FY 2007 Congressional Budget justification is available on the Office of Chief Financial Officer/CFO homepage at http://www.mbe.doe.gov/budget
Source	Department of Energy
Document Type	Annual Report (Adobe Postscript file)
Resource Date	02/2006

Post Date	02/01/2006
Title	THIN FILM PV PARTNERSHIP
Link	(MS Word 393 KB)
Author	K. Zweibel
Description	Objectives Support the near-term transition to first-time manufacturing and commercial introduction of reliable thin-film a-Si, CIS, CdTe, and film silicon modules. Build a technology base upon which these advanced PV technologies can successfully improve manufacturing and continue to progress in terms of performance, reliability, and reduced cost for products meant to compete in the PV marketplace. Sustain innovation to support progress toward ambitious long-term PV cost and performance goals (e.g., 15% modules at under $50/m2 and capable of lasting 30 years) appropriate for cost-competitive PV electricity. Accomplishments Four JOULE milestones were met. Two Technology Partners broke ground on major manufacturing expansions (First Solar 50 MWp, and Uni-Solar 25 MWp). Production of thin films in the United States grew from 12 MWp in 2003 to an estimated >40 MWp in 2005. Future Directions � Continue to address key issues supporting the transition to successful first-time manufacturing or major production expansion in each thin film. � Significantly reduce CIS and CdTe layer thicknesses in cells and support transfer of this to manufacturing. � Direct CdTe research toward higher voltage. � Investigate nano-crystalline bottom cells for thin-film silicon multijunctions.___________________________________________
Venue	DOE NREL Annual Report
Source	National Renewable Energy Laboratory
Document Type	Annual Report (Word document)
Resource Date	02/2006

Post Date	11/11/2005
Title	POLYCRYSTALLINE THIN FILM DEVICE DEGRADATION STUDIES
Link	(PDF 85 KB) Download Acrobat Reader.
Author	D. Albin
Description	Oxygen during vapor CdCl2 (VCC) treatments significantly reduced resistive shunts observed in CdS/CdTe polycrystalline devices using thinner CdS layers during 100 �C, open-circuit, 1-sun accelerated stress testing. Cu oxidation resulting from the reduction of various trace oxides present in as-grown and VCC treated films is the proposed mechanism by which Cu diffusion, and subsequent shunts are controlled. Graphite paste layers between metallization and CdTe behave like diffusion barriers and similarly benefit device stability. Ni-based contacts form a protective Ni2Te3 intermetallic layer that reduces metal diffusion but degrades performance through increased series resistance.
Venue	DOE Solar Review Meeting 2005 paper
Source	National Renewable Energy Laboratory
Document Type	Annual Report (Adobe Postscript file)
Resource Date	11/10/2005

Post Date	03/15/2005
Title	SOLAREX OTF ROOF SYSTEM
Link	(MS Word 96 KB)
Author	J. Adelstein
Description	This report is a quarterly update of the performance, based on the PVUSA power rating system, of the Solarex 1.2 kWac a-Si system being monitored at NREL. The system has been monitored over the 4 year period from September 1999 through December 2003. The PV array consists of 36 utility grid tied Solarex MST-43MV modules plus 6 ?dummy? modules, not connected to the power grid, and is located on the roof of NREL?s Outdoor Test Facility (OTF). It faces south (+/- 5o) with a tilt angle from the horizontal equal to 40� (latitude) and is connected to the utility grid through a 2.2 kW Omnion Series 2400 inverter in bi-polar configuration.
Venue
Source	National Renewable Energy Laboratory
Document Type	Annual Report (Word document)
Resource Date	09/21/2004

Post Date	02/02/2005
Title	2003 DOE PV PEER REVIEW
Link	(PDF 716 KB) Download Acrobat Reader.
Author	N/A
Description	Review of DOE PV activities in 2003
Venue	US DOE EERE
Source	US DOE
Document Type	Annual Report (Adobe Postscript file)
Resource Date	09/30/2003

Post Date	05/30/2006
Title	ADVANCED PROCESSING OF CDTE- AND CUIN1-XGAXSE2 CELLS
Link	(PDF 1.0 MB) Download Acrobat Reader.
Authors	C. S. Ferekides, D. Morel
Description	This is the final report for the 3-year project with subcontract # NDJ-2-30630-18. The CdTe section of the report is organized in 2 major sections: (a) a summary of the activities and major results obtained during the first two 2 years (covered in Annual Reports I & II), and (b) activities for year 3. Additional details will be provided within the subsequent sections.
Venue	NDJ-2-30630-18
Source	University of South Florida, Tampa
Document Type	Final Report (Adobe Postscript file)
Resource Date	05/2006

Post Date	02/07/2005
Title	PV STATUS REPORT 2003
Link	(PDF 671 KB) Download Acrobat Reader.
Author	A. Jager-Waldau
Description	Research, Solar Cell Production and Market Implementation in Japan, USA and the European Union.
Venue	European Commission JRC EUR 20850EN
Source	Institute for Environment and Sustainability
Document Type	Final Report (Adobe Postscript file)
Resource Date	09/2003

Post Date	05/17/2005
Title	ADHESION STRENGTH STUDY OF EVA ENCAPSULANTS ON GLASS SUBSTRATES
Link	(PDF 493 KB) Download Acrobat Reader.
Authors	S. H. Glick, F. J. Pern
Description	An extensive peel-test study was conducted to investigate the various factors that may affect the adhesion strength of photovoltaic module encapsulants, primarily ethylene-vinyl acetate (EVA), on glass substrates of various laminates based on a common configuration of glass/encapsulant/backfoil. The results show that "pure" or "absolute" adhesion strength of EVA-to-glass was very difficult to obtain because of tensile deformation of the soft, semi-elastic EVA layer upon pulling. A mechanically "strong enough" backing foil on the EVA was critical to achieving the "apparent" adhesion strength. Peel test method with a 90-degree-pull yielded similar results to a 180-degree-pull. The 90-degree-pull method better revealed the four stages of delamination failure of the EVA/backfoil layers. The adhesion strength is affected by a number of factors, which include EVA type, formulation, backfoil type and manufacturing source, glass type, and surface priming treatment on the glass surface or on the backfoil. Effects of the glass-cleaning method and surface texture are not obvious. Direct priming treatments used in the work did not improve, or even worsened, the adhesion. Aging of EVA by storage over ~5 years reduced notably the adhesion strength. Lower adhesion strengths were observed for the blank (unformulated) EVA and non-EVA copolymers, such as poly(ethylene-co-methacrylate) (PEMA) or poly(ethylene-co-butylacrylate) (PEBA). Their adhesion strengths increased if the copolymers were cross-linked. Transparent fluoropolymer superstrates such as TefzelTM and DureflexTM films used for thin-film PV modules showed low adhesion strengths to the EVA at a level of ~2 N/mm.
Venue	CP-520-33558
Source	National Renewable Energy Laboratory
Document Type	Final Report (Adobe Postscript file)
Resource Date	05/2003

Quarterly Reports

Post Date	12/13/2007
Title	BARRIER COATINGS AND STABILITY OF THIN FILM SOLAR CELLS
Link	(PDF 51 KB) Download Acrobat Reader.
Author	L. Olsen
Description	Data were acquired for SSI mini-modules that were coated with PNNL barrier coatings based on the new polymer blend. Results were obtained for coated modules subjected to 85�C and dry conditions, and modules with barrier coatings of thicknesses ranging from 3 microns to 10 microns. The 85�C/Dry testing was done to determine if the coatings react in a negative way with the devices. We found that all coated modules were stable in the 85�C/Dry conditions. Figure 3 gives results for a module with a coating 10 microns thick. Basically, the module is stable. Thus, it is very clear that the SSI mini-module can tolerate 85�C and dry conditions, but not a stress of 86�C/85%RH. Figure 4 gives results for coated mini-modules with the results for a bare module shown for contrast. Although the PNNL barrier coatings have made a tremendous difference, degradation still occurs. The fact that all modules degrade at the same rate, regardless of coating thickness, provides an important clue as to the cause of the degradation. Based on our overall experience, the effectiveness of the barrier coatings should improve with thickness. In general, we find that there are three cell features that can lead to defects in the multi-layer coatings which in turn provide a path for water diffusion: (i) Surface roughness; (ii ) Inadequate edge seal; (iii) Cuts separating individual cells. Since the rate of degradation of efficiency is independent of the coating thickness, we suspect that features (ii) and (iii) are most likely responsible for causing pathways of moisture diffusion. Further studies are required before this problem(s) can be clearly identified. However, the results achieved with the new polymer blends in an 85/85 environment are very encouraging.
Venue	Pacific Northwest National Laboratory, subcontract DAX-4-44239-01, quarterly report
Source	Pacific Northwest National Lab (PNNL)
Document Type	Quarterly Report (Adobe Postscript file)
Resource Date	12/01/2007

Post Date	11/29/2007
Title	CHARACTERIZATION AND ANALYSIS OF CIS AND CDTE CELLS
Link	(PDF 70 KB) Download Acrobat Reader.
Author	J. R. Sites
Description	During the past quarter, two students completed their PhD and one other is preparing for his defense. At the same time, we expanded our work on the analysis of cells with non-uniformities, we began a collaboration on CIGS made with laser-assisted deposition, and we continued several measurement and analysis projects in collaboration with other laboratories.
Venue	Colorado State University, subcontract XXL-5-44205-03, quarterly report
Source	Colorado State University
Document Type	Quarterly Report (Adobe Postscript file)
Resource Date	09/24/2007

Post Date	08/15/2007
Title	BARRIER COATINGS AND STABILITY OF THIN FILM SOLAR CELLS
Link	(PDF 89 KB) Download Acrobat Reader.
Author	L. Olsen
Description	The key objectives of the program are to develop low cost barrier coatings for CIS and CdTe solar cells and to develop an improved understanding of the effects of water on the stability of these types of cells. The scope of this work entails investigations multilayer, barrier coatings for CIS and CdTe thin film solar cells, and studies of stability issues, particularly those related to moisture ingress. Investigation of barrier coatings on SSI and CSU devices will continue in an effort to establish effective approaches encapsulate CIS and CdTe modules. Studies will also be directed towards issues concerning cost of the coating process. The program will be structured into three major tasks: (1) Barrier coatings and stability studies for CIS Solar Cells; (2) Barrier coatings and stability studies for CdTe solar cells; (3) Low cost coating process development.
Venue	PNNL, agreement DAX-4-44239-01, quarterly report
Source	Pacific Northwest National Lab (PNNL)
Document Type	Quarterly Report (Adobe Postscript file)
Resource Date	06/2007

Post Date	08/15/2007
Title	BARRIER COATINGS AND STABILITY OF THIN FILM SOLAR CELLS
Link	(PDF 56 KB) Download Acrobat Reader.
Author	L. Olsen
Description	Our investigations to date were based on Shell Solar, Inc. (SSI) cells and mini-modules. We found that these cells were extremely vulnerable to damp heat effects. These devices are no longer available to PNNL due to the closing of the Chatsworth CIGS operation. However, we have a supply of 2 in. x 2 in. mini-modules that were used in recent studies that are discussed in this report. Moisture ingress is apparently not an issue if modules are fabricated with glass-to-glass construction. It is clear, however, that CIGS cells and modules fabricated on flexible substrates must have an effective barrier coating. As a result, we plan to concentrate on establishing baseline information concerning the effects of damp heat on CIGS.
Venue	PNNL, agreement DAX-4-44239-01, quarterly report
Source	Pacific Northwest National Lab (PNNL)
Document Type	Quarterly Report (Adobe Postscript file)
Resource Date	05/2007

Post Date	03/14/2007
Title	BARRIER COATINGS AND STABILITY OF THIN FILM SOLAR CELLS
Link	(PDF 47 KB) Download Acrobat Reader.
Author	L. Olsen
Description	Studies of photoluminescence in CdTe solar cell structures continued. The objective of this effort is to determine if the PL spectrum for a CdTe device is affected by stress. In particular, we are interested in determining if moisture affects carrier properties. Samples studied were cell structures without back contacts previously provided by CSU. Figure 1 describes our approach to PL studies. This figure is repeated from the last quarterly report. An excitation wavelength of 580 nm was used and band gap emission observed for the excitation beam entering through the glass and through the CdTe side.
Venue	PNNL, DAX-4-44239-01, quarterly report
Source	Pacific Northwest National Lab (PNNL)
Document Type	Quarterly Report (Adobe Postscript file)
Resource Date	01/2007

Post Date	09/28/2006
Title	BARRIER COATINGS AND STABILITY OF THIN FILM SOLAR CELLS
Link	(PDF 42 KB) Download Acrobat Reader.
Author	L. Olsen
Description	Efforts have concentrated on establishing procedures for collaboration with Dr. Sampath's group at CSU and Dr. Compaan's group at the University of Toledo. In both cases, we have supplied patterned SnO2 - coated glass for growth of CdS/CdTe structures. It turns out, however, that removing SnO2 from LOF TEC 15 is not trivial. We received valuable guidance from Dr. Sampath. Referring to Figure 1, we plan to start with SnO2 -coated glass, pattern the SnO2 as illustrated in Figure 1A, send the substrates to CSU and UT for growth of CdS/CdTe devices. In the case of CSU, the back contact will be applied at PNNL for some of the structures. Removing the tin-oxide has turned out to be non-trivial.
Venue	PNNL, Purchase Order DAX-4-44239-01, quarterly report
Source	Pacific Northwest National Lab (PNNL)
Document Type	Quarterly Report (Adobe Postscript file)
Resource Date	08/2006

Post Date	07/25/2006
Title	BARRIER COATINGS
Link	(MS Word 145 KB)
Author	L. Olsen
Description	Coatings to protect thin film cells.
Venue	Quarterly Phase 2, #2
Source	Pacific Northwest National Lab (PNNL)
Document Type	Quarterly Report (Word document)
Resource Date	07/2006

Post Date	05/30/2006
Title	BARRIER COATINGS AND STABILITY OF THIN FILM SOLAR CELLS
Link	(MS Word 87 KB)
Author	L. Olsen
Description	CdTe cell structures provided by CSU were stressed and then characterized with XPS in an effort to understand the effects of moisture on CdTe devices. If we assume the emission is primarily due to oxides on the grain boundaries, it appears that the unknown complex oxide could play a key role in grain boundary passivation. It could therefore be very valuable to determine the identity of this complex oxide. Based on results for the stressed cell, significant effects of the 60�C/90%RH stress may be formation of Cd(OH)2 along grain boundaries, and elimination of the unknown complex Cd-based oxide along the grain boundaries. If we assume that the unknown oxide is important for grain boundary passivation and/or the hydroxide results in increased recombination at grain boundaries, then it is understandable that both Jsc and Voc would decrease as a result of damp heat. We conclude, therefore, that damp heat does more than just degrade the contacts in CdTe cells. In particular, it appears that formation of Cd(OH)2 leads to increased recombination at grain boundaries, which decreases cell quantum efficiency and increases current losses (larger Jo).
Venue	1st Quarterly Report - Phase II: September 1, 2005 -- November 30, 2005 NREL Subcontract: 48027
Source	Pacific Northwest National Lab (PNNL)
Document Type	Quarterly Report (Word document)
Resource Date	05/2006

Post Date	09/06/2005
Title	OUTDOOR MONITORING AND HIGH VOLTAGE BIAS TESTING OF THIN-FILM PHOTOVOLTAIC MODULES
Link	(MS Word 4.2 MB)
Author	N. G. Dhere
Description	Outdoor monitoring and High Voltage Bias Testing of Thin-Film Photovoltaic Modules has been undertaken through the project funded by NREL for a period of three years. This is the Year 2, Quarter 3 Report, FSEC-CR1523-05 for the period April-June 2005. The report contains the tasks carried out to modify the data acquisition process and completion of all the modifications suggested by NREL. This work consists of the study of outdoor testing and monitoring of photovoltaic (PV) thin-film modules fabricated by First Solar (Glass/CdTe/Glass), Shell Solar (Glass/CIS/Glass), United Solar (a-Si:H on flexible substrate), Energy Photovoltaics (Glass/a-Si:H/Glass), and Global Solar (CIS on flexible stainless steel foil substrate) with 1 additional crystalline silicon module in the hot and humid climate of Florida.
Venue	Year 2, Quarter 3 Report FSEC-CR 1523-05 July 29, 2005
Source	FLorida Solar Energy Center
Document Type	Quarterly Report (Word document)
Resource Date	09/2005

Post Date	08/04/2005
Title	BARRIER COATINGS AND STABILITY OF THIN FILM SOLAR CELLS
Link	(MS Word 3.4 MB)
Author	L. Olsen
Description	Work concentrated on studies concerning encapsulation of CdTe cells. Three topics are discussed: further consideration of results for a CSU cell encapsulated with a single dyad/Al-film combination; results for studies of stressed bare cell cells from CSU and University of Toledo; and studies of encapsulated calcium samples subjected to heat and humidity conditions.
Venue	3rd Quarterly Report - Phase I: March 1, 2005 -- May 31, 2005
Source	Pacific Northwest National Lab (PNNL)
Document Type	Quarterly Report (Word document)
Resource Date	07/2005

Post Date	06/27/2005
Title	BARRIER COATINGS AND STABILITY OF THIN FILM SOLAR CELLS
Link	(MS Word 1.8 MB)
Author	L. Olsen
Description	The key objectives of the program are to develop low cost barrier coatings for CIS and CdTe solar cells and to develop an improved understanding of the effects of water on the stability of these types of cells. The scope of this work entails investigations of multilayer, barrier coatings for CIS and CdTe thin film solar cells, and studies of stability issues, particularly those related to moisture ingress. Investigation of barrier coatings on SSI and CSU devices will continue in an effort to establish effective approaches to encapsulate CIS and CdTe modules. Studies will also be directed towards issues concerning cost of the coating process. The program will be structured into three major tasks: (1) Barrier coatings and stability studies for CIS Solar Cells; (2) Barrier coatings and stability studies for CdTe solar cells; (3) Low cost coating process development.
Venue	2nd Quarterly Report - Phase I: December 1, 2004 -- February 28, 2005
Sources	Colorado State University; Pacific Northwest National Lab (PNNL)
Document Type	Quarterly Report (Word document)
Resource Date	06/2005

Post Date	05/27/2005
Title	OUTDOOR MONITORING AND HIGH VOLTAGE BIAS TESTING OF THIN-FILM PV MODULES IN HOT AND HUMID CLIMATE
Link	(PDF 192 KB) Download Acrobat Reader.
Author	N. G. Dhere
Description	All modules had been brought to horizontal position and tied in August 12, 2004 because of hurricane Charlie. The modules were uninstalled on Sep 2-3, 2004 because of hurricane Frances and were re-installed during Sep 13-20, 2004. The modules were again uninstalled on Sep 22-23, 2004 and re-installed during Sep 27-30, 2004 because ofricane Jeanne. Since hurricane warnings continued until mid-November, all connections were not completed and data collection could not be initiated. All the modules and electrical circuits were completely reinstalled by the beginning of December 2004. After all the modifications, test data collection began on December 09, 2004. PV Materials Lab has installed one datalogger with two multiplexers and another datalogger with one multiplexer to measure the various parameters. All the voltages, currents and temperatures are being monitored with the first datalogger using two multiplexers. Multiplexer 1 is used to collect all the voltages and some temperature data and multiplexer 2 is used to collect currents and temperature values. High voltage leakage currents and ambient parameters such as solar irradiance, relative humidity, ultraviolet radiation intensity, wind speed and pressure are monitored with the second datalogger.
Venue	subcontract ZDJ-3-33600-02, quarterly report
Source	FLorida Solar Energy Center
Document Type	Quarterly Report (Adobe Postscript file)
Resource Date	04/20/2005

Post Date	05/25/2005
Title	OUTDOOR MONITORING AND HIGH VOLTAGE BIAS TESTING OF THIN-FILM PV MODULES IN HOT AND HUMID CLIMATE
Link	(MS Word 710 KB)
Author	N. G. Dhere
Description	As reported earlier, all the FS, SS, USSC and EPV modules were reinstalled by September 30, 2004. The Global Solar modules have also been installed recently. The circuit used earlier for data acquisition was modified. A shunt to measure the current, two fuses, a circuit breaker and two blocks for I-V Measurements