the importance of backsheets when choosing panels
TRANSCRIPT
The Importance of Backsheets When Choosing Panels
q This webinar will be available afterwards at www.solarpowerworldonline.com & email
q Q&A at the end of the presentation q Hashtag for this webinar: #SolarWebinar
Before We Start
Kelly Pickerel Solar Power World
Moderator Presenter
Lee Smith Dunmore
Installation Stress
• Physically getting modules on roof • Sharp corners • Not getting shocked
Installation-challenges
Installation-challenges
Installation-challenges
Installation-challenges
Overview
• What is backsheet? • Backsheet failures • The failure rate for solar modules • Module types
– Crystalline – Thin film
• Warranties • Who is responsible if the module fails?
What is Backsheet The outermost back layer. What does it do? • Makes the module light. • Protects the installer. • Keeps the adhesive from • yellowing. • Reflects to increase
energy.
TEXTBOOK REFLECTION OF LIGHT OFF BACKSHEET TO FRONT GLASS TO CELL
Handbook of Photovoltaic Science and Engineering
Typical Backsheet Construction
PV Module Stresses Protection from:
● UV- Rays
● Temperature changing
○ - 40°F to 185°F
● Humidity and vapor
● Dryness / wind / dust / sand
● Scratches during installation and maintenance
● Electrical insulation
Internal Testing • Damp Heat Test (external TUV 85°C and 85% r.h.) • Damp Heat Test (internal 85°C and 85% r.h.) • Partial Discharge Test at TUV and VDE • Turbo Damp Heat Test (120°C and 100% r.h.) • Peel Test 90° (internal method) • UV-Test (IEC 61215) • Shrinkage Test (150°C and 30 min) • Water Vapor Barrier Test • Special UV-Test at ISE Fraunhofer Institute Freiburg (IEC 61215) • UV - Damp Heat Combination Test at ISE Fraunhofer Institute
UV - Damp Heat Combination Test
Climate chamber with UV light source - Fraunhofer
PV Backsheet Failure
Module Field Failure
Module Replacement Rates
How often can they fail? • National Renewable Energy
Laboratory (NREL) – 2012 NREL Reliability
Workshop • Workmanship Warranties
went from 2 to 10 years.
Crystalline Modules
• Typical flat panel • Rigid • Oldest type • Black or blue cells
When Thin is More • Flexible PV modules
– No need for mounting racks – No roof penetration – Higher surface area
• Ideal applications – Light weight roofs – High wind areas – Curved surfaces – Flat roof applications
Image credit: Global Solar
Warranty • Can be confusing
– Power Purchase Agreement (PPA) – Lease agreement – Engineering, Procurement & Construction (EPC)
agreement – Operations & Maintenance agreement (O&M)
• Crystal clear • Failure is on your customer’s roof • You’re going to be the first person they contact
Reputation
• Reputation of the manufacturer • Your reputation
Questions? Kelly Pickerel Solar Power World [email protected] Twitter: @solarkellyp
Lee Smith Dunmore [email protected]
q This webinar will be available at www.solarpowerworldonline.com & email
q Tweet with hashtag #SolarWebinar
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Thank You