Post on 10-Aug-2021
transcript
www.strsolar.com
Are your modules STR Protected™
?
Specialized Technology Resources, Inc. (STR) is the global leader in encapsulant technology for the solar module industry. STR has been manufacturing encapsulants for more than 30 years with zero field failures. Our products offer distinct competitive advantages that increase the bankability of our customer’s modules.
Given the high capital investment required to build solar projects and a module lifetime expectancy of more than two decades, it is critical to select a module brand that is “Bankable” to increase project IRR. STR believes that its ability to cite performance data over a multi-decade time frame serves to remarkably improve a module manufacturers’ bankability.
Ethylene Vinyl Acetate (EVA) has been the primary material used in solar encapsulants for the last few decades. STR PHOTOCAP® EVA is the only encapsulant technology with a proven track record of maintaining durability, adhesion, stability and transparency after more than 25 years of field exposure.
STR not only offers encapsulant with proven superior performance, but we work directly with our customers to improve their lamination processes and in turn, improve the quality of their modules, increase yield and reduce costs.
STR has been at the technology forefront of the solar encapsulant business for three decades and has retained its dominance by continually increasing the value of its products. It is abundantly clear that STR offers a level of technical and customer service unmatched by the competition. STR not only sells a premium product but “it also sells its engineers and scientists.”
Photovoltaic Solar Module Reliability and
Durability
Choosing the right solar encapsulant to protect the longevity of the solar module is the single-most important decision a developer or project owner will make.
PHOTOCAP® is a registered trademark of Specialized Technology Resources
Are your modules STR Protected™?
What happens when a project owner buys solar modules from a supplier that uses an inexpensive encapsulant and the power generation significantly declines over the life of the product? Who covers the cost?
A. Specialized Technology Resources, Inc. has been developing and producing solar encapsulant for over 35 years (circa 1975); through advanced engineering and time-tested durability.
Q. How has STR upheld high quality standards to safeguard solar modules?
How will you know that solar module components will perform as intended?
The solar industry is
challenged with collecting
energy and collecting it in
a cost effective way.
The value of any PV module
is determined by durability,
life-cycle, interest rates, and
cost of the materials used in
that device.
Cost Performance[P(t=∞)]Must Be Minimized
Must Be Demonstrated
The Solar Industry is Embattled With Opposing Forces.
Project IRR increases with long-term module performance.
Must Be Maximized
Durability[P(t)]
“Lifetime” 25 years
INDUSTRY FORCES
• STR Has Been Making Quality Encapsulant Since 1975
• More Than 20 Gigawatts of STR Protected™ Modules in the Field
• No Reported Failures of STR Encapsulant in Fielded Modules
• Unsurpassed Long-term Optical Performance of STR Encapsulant Facilitates Maximum
Power Output
Encapsulant reliability
requires accurate,
repeatable formulation,
top quality raw materials
and strict process control.
*“Bankability” is a financial industry term defined as “preferential to a bank” and “dependable and reliable.”
Bankability in the solar energy industry is another word for “risk mitigation.”
Solar Module “Bankability”* is a Function of Reliability and Durability.Investors in the solar industry are gaining a better understanding of how to calculate actual returns on investments. Discussions regarding price are moving from a capacity basis, traditionally discussed in terms of cost per watt, to an energy generation basis, which is discussed in terms of cost per kilowatt-hour of energy produced and represented by estimated levelized cost of electricity (LCOE).
In today’s PV market, everyone from system owners to start up thin-film PV firms will tell you about their calculated LCOE. Many assumptions go into this calculation, one of those key assumptions being the system degradation rate, which is highly dependent on the stability of your encapsulant.
BANkABILITYSTR PROTECTED
Consider This… Module Components Impact Module Durability.
STR Encapsulant Touches Every Component of the Solar Module, Therefore it Must Be Chemically & Physically Compatible to Enhance Module Durability.
Encapsulants are critical to solar modules, as they protect cells from the elements, bond the multiple layers together, and provide electrical isolation. Encapsulants must have high optical transparency, stability at high operating temperatures, the ability to withstand high levels of ultraviolet radiation, good adhesion to different module materials, adequate mechanical compliance to accommodate stresses induced by differences in thermal expansion coefficients between glass and cells, and high dielectric strength (electrical isolation). Even a slight deterioration of any of the properties of the encapsulant over time will impair the electrical output of the module, which is of critical importance to providing a 20 to 25-year working life of a solar module.
During solar module assembly, the encapsulation process is typically accomplished by vacuum lamination, wherein a “pre-lam” stack (as depicted in the diagrams to the right) is fashioned into a singular part comprising multiple layers. Sheets of EVA are inserted over and under the PV cells. Heating the “sandwich” then causes the EVA to cure, thus bonding the module into one piece. This step occurs towards the end of the manufacturing process and is critical to the entire solar module, as there is only one opportunity to laminate correctly.
Function of the EVA Encapsulant
• Bond All Components Together• Weatherability of the PV Device (up to 25 years)• High Light Transparency for Cell Efficiency• Electrical Isolation of the PV Device• Increase Stress Load of Glass• Moisture Ingress Protection• Allow Expansion and Contraction
Typical Crystalline Silicon Solar Module Construction
Typical Thin Film Solar Module Construction
Glass
Top Side EVA Encapsulant
Cells
Back Side EVA Encapsulant
Back Sheet
Glass
EVA EncapsulantDeviceGlass
DURABILITYSTR PROTECTED
Solar Module Component
Function of STR PHOTOCAP® EVA Encapsulant Benefits of STR Protected™
Glass Mechanical Stress Load Management
STR encapsulant minimizes stress load to cells; provides a thermal expansion buffer and absorbs stress to prevent cell cracking as well as module deformation. Bonds cells to glass.
PV Cell
Electrical Isolation STR encapsulant has high volume resistivity to minimize current leakage; high dielectric strength.
High Light Transmission STR encapsulant maintains clarity and is optically designed to allow a broad band of light transmission.
Dimensional Stability STR encapsulant does not move or shrink during lamination preventing void formation over cells, movement of cell strings, and cell breakage.
Mechanical Protection STR encapsulant physically isolates the cells and can absorb stresses that lead to cell cracking.
PV Ribbon Electrical Isolation STR encapsulant is compatible with most surfaces to maintain high dielectric strength.
Backsheet
Strong Adhesion STR encapsulant helps to protect the backsheet from yellowing; bonds cells to backsheet.
Chemically Compatible With Tie-Layers STR encapsulant bonds well to the backsheet.
Physical Robustness STR encapsulant provides a level of cut/tear resistance along with high bond strength.
BENEFITSSTR PROTECTED
Probably the oldest and most widely discussed solar module differentiator is module efficiency. Maintaining high module efficiency over time means that project IRR can be maximized, because electricity generation remains at expected rates. STR PHOTOCAP® EVA encapsulant does not discolor and helps to maintain original cell efficiency while being a small part of the overall cost of the solar module.
Poorly Formulated EVA Encapsulant Can Stain Back Sheet After Weathering
Some EVA Encapsulants Contain Additives That React and Turn the Encapsulant Brown
Some EVA Encapsulants Weather Poorly, Turning Yellow
STR PHOTOCAP® EVA Encapsulant is Engineered to Remain Clear After Weathering
Left: A Poorly Formulated EVA Encapsulant will Discolor and turn Yellow or Brown from Outdoor Exposure. The result is a drastic reduction in cell efficiency
MODULE DELAMINATION is the loss of adhesion between the encapsulant and other module layers. Delamination in the field can occur in cases where the encapsulant was improperly cured or where chemical incompatibilities between the encapsulant and other module components exist. Most of the delamination observed in the field has occurred at the interface between the encapsulant and the front surface of the solar cells or back sheet in the module. Delamination is more frequent and more severe in hot and humid climates, sometimes occurring after less than five years of exposure. Delamination first causes a performance loss due to optical de-coupling of the encapsulant from the cells. Of greater concern, is the likelihood that the void resulting from the delamination will provide a preferential location for moisture accumulation, greatly increasing the possibility of corrosive failure in metallic contacts.
FOR HIGH EFFICIENCY
Not All Encapsulants Are Formulated the Same!
FORMULATION “MASTERY”STR PROTECTED
STR-Owned Test Tracker in Arizona Yields 22-Year* Weathering Exposure and Power Analysis.Should you wager the value of your installation only on module validation data? When you’re STR Protected™, you won’t have to!
Pictured below is STR’s two-axis tracker in Tempe, AZ, USA – one of the sunniest places on earth. STR Scientists fielded modules with our key platform encapsulant formulations on this tracker in 1996 to evaluate their effectiveness at maintaining power output under the harshest of real-time, actual outdoor conditions. Our confidence is data-driven. Accept no substitutes.
*Two-axis tracking acceleration factor of 1.6 yields 22 years (in equivalent years)
STR Ultra-Fast Cure Encapsulant
STR Ultra-Fast Cure Encapsulant
Time on Tracker (equivalent years)
Time on Tracker (equivalent years)Re
lativ
e Po
wer
Pm
ax (%
)Re
lativ
e Sh
ort C
ircui
t Cur
rent
, Isc
(%)
080
85
90
95
100
105
8 16 24
080
85
90
95
100
105
8 16 24
TIME-TESTEDSTR PROTECTED
STR PHOTOCAP® EVA Does Not Shrink During Lamination to Protect Cells from Breakage and Movement Before and During Lamination.
Our EVA Touches Everything in the Module.Another important aspect of the encapsulant is dimensional stability. Shrink or inadequate adhesion during the lamination process of the PV solar modules can occur, and may result in voids or holes in the encapsulant during module lamination, which are considered defects and cause for rejection of the entire panel. The encapsulant is susceptible to several performance failures that can jeopardize the integrity and performance of the entire solar module, and lead to significant warranty costs.
STR Protected includes “User-Friendly” No Shrink Technology during the manufacturing of its encapsulant. This means ZERO Shrink and NO adverse impact on adhesion to glass, cell or backsheet, which can harm your modules in the field.
STR User Friendly (UF) Technology results in zero Shrink.
Competitive materials shrink during lamination.
LEADING EDGE TECHNOLOGYSTR PROTECTED
High Technology Formulations to Protect EfficiencyXenon Arc Accelerated Aging
Time in XAW (years)
Yello
wne
ss In
dex 15455P/UF Mega-Fast
Cure Encapsulant15420P/UF Ultra-Fast Cure EncapsulantCompetitor 1Competitor 2
00 4 8 12 16 20 24 28
5101520253035
072 120 168 264 408
20
40
60
80
100High Temperature (130˚C Heat Soak)
Time in XAW (hours)
Yello
wne
ss In
dex
15420P/UF Ultra-FastCure EncapsulantCompetitor 1Competitor 2Competitor 3
STR encapsulant outperforms the competition in high temperature accelerated weathering.
Subtle Chemical Deviations Have a Profound Impact on PV Module Performance. No Two EVA Encapsulant Formulations are Alike.Accelerated xenon arc weather testing can give a good indication of the performance of the encapsulant. Several competitive encapsulants were evaluated by STR. The truth is that no two encapsulants behave the same.
Time in XAW (in equivalent years: 2 weeks = 1 year)
Yello
wne
ss In
dex
(AST
M D
-192
5)
0
0
2
4
6
8
10
12
14
16
18
5 10 15 20 25
15420P/UF Ultra-Fast Cure EncapsulantCompetitor 1Competitor 2Competitor 3Competitor 4Competitor 5
Xenon Arc Weatherometer ExposureYellowness Index
STR’s long-term accelerated aging studies, coupled with our field testing, show that two weeks in accelerated chambers approximates almost one year in the field. STR encapsulants maintain clarity and photothermal stability.
Encapsulant discoloration reduces module power output. Encapsulant yellowing will diminish cell efficiency.
Poorly Formulated Encapsulants Will Degrade More Rapidly in High Temperature Environments, Reducing Module Output.
00.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
5 10 15 20 25
% Transmission Loss vs. EVA Yellowing
∆ Yellowness Index
Loss
in S
olar
Inte
grat
edTr
ansm
issi
on (∆
%T)
ADVANCED ENGINEERINGSTR PROTECTED
It All Starts with World-Class Internal Quality.STR Quality Control sets the industry standard for perfection in EVA encapsulant manufacturing. STR’s goal is 100% customer satisfaction—full stop. We achieve our goal with ZERO module returns from the field using STR PHOTOCAP® EVA encapsulant.
There are rogue encapsulant manufacturers existing in the industry. These companies don’t offer the time-tested assurance that their product will not discolor and degrade cell efficiency when weathered outdoors. STR has the industry time-tested expertise.
All cost/benefit tests point to STR PHOTOCAP® EVA as the practical choice for solar encapsulants. STR has over 35 years of formulatory knowledge for PV applications.
STR knows that modules containing STR PHOTOCAP® EVA encapsulant will perform as expected over the service life of the module. There are non-STR modules in the field today that have been recalled due to yellowing and/or visible signs of discoloration. If left unattended these modules will continue to decline in power output over time.
• World Class Global Quality
• Dashboard Metrics of Key Performance Parameters
• On Time Delivery
• Supply Chain Quality
• In-process/Final Quality Checks
• Global CAPA System on Manufacturing Lines
• Timely Corrective Action Board
• Six Sigma Philosophy
• Six Sigma Certified Black Belt(s)
• FMEA - Control Analysis
• Quality Manager/Staff at Each Site
• All Sites ISO 9001 Certified
• All STR Sites are UL Listed
Please Make Sure that You Are STR Protected!
Make Sure That You Have Time-Tested STR PHOTOCAP® EVA Encapsulant Inside.
WORLD-CLASS QUALITYSTR PROTECTED
STR ESPAÑA, S.A.PARquE TEcnológico dE ASTuRiAS, PARcElA 3633428 – llAnERA, ASTuRiASSPAinPhonE: +34-985-73-23-33FAx: +34-985-73-36-62
STR MAnuFAcTuRing locATionS
1699 King STREET, SuiTE 400EnFiEld, cT 06082 uSAPhonE: +1-860-758-7300FAx: +1-860-758-7301
STR coRPoRATE hEAdquARTERS
STR, inc.18 cRAFTSMAn RoAdEAST WindSoR, cT 06088 uSAPhonE: +1-860-763-7014
STR MAlAySiA Sdn BhdPloT 20, JAlAn TAnJung A/3PoRT oF TAnJung PElEPAS81560 gElAng PATAh, JohoRMAlAySiAPhonE: +607-507-3186FAx: +607-507-3190
gloBAl REAch
www.strsolar.com
The information, statements and recommendations contained herein are based on information, data, reports or tests believed to be reliable. however, Specialized Technology Resources, inc. makes no warranty or guarantee of accuracy or completeness in connection therewith, nor, with respect to any Specialized Technology Resources, inc. products involved, any warranty or merchantability or fitness for a particular purpose or use.
www.ul.com Keyword: PhoTocAP
iSo certification iSo 9001: 2008 STR, uSiSo 9001: 2008 STR, SpainiSo 9001: 2008 STR, Malaysia
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