TÜV Rheinland Solar 2013 Quality Monitor
Photovoltaics: Fault Statistics from Module Certification Number of Certification Projects in Which Tests Were 2,000 certification projects in Germany from 2002 to 2012 (c-si and TF are shown separately as of 2007) 67% Mainly European products displayed as of 2008 (TÜV Rheinland laboratories opened in Japan, China, USA, Taiwan, India, and Korea) 54% 53% Thin-film and crystalline modules shown separately as of 2007 27% 30% 40% 39% 29% 30% 26% 21% 22% 19% 17% High number of new Chinese manufacturers in 2004 2007 Many thin-film start-ups as of 2007/2008 10% 10% 10% 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Crystalline technologies Thin-film technologies Both technologies Today, modules are being constructed that fulfill the standard. 2
Photovoltaics: Fault Statistics from Module Certification Fault Distribution by Technology (2006 2013): Crystalline (1,740 projects; inner ring) and thin-film (370 projects; outer ring) Example of Development of Individual Fault 1,580 projects analyzed with crystalline modules 50% 40% 30% 10% 12% 11% 11% 7% 3% 10% 4% 18% 9% 6% 8% 9% 9% 17% 22% 4% 9% 10% 5% 6% Incoming measurements 200 temperature cycles Moisture/thermal test Moisture/freeze test 50 temperature cycles Hot spot test Mech. load test Optional load 5,400 Pa Scratch test Bypass diode test Reverse current loading Light-induced aging Further tests (< 3%) 20% 10% 0% 2006 2007 2008 2009 2010 2011 2012 200 temperature cycles Moisture/thermal Mech. Load Approx. 50% of tests failed were climate tests > 10% of faults occurred before any load tests were performed: - Identification plate information - Workmanship quality - El. isolation Temperature cycles stress solder connections, therefore higher proportion among crystalline technologies 3
Assessment of Workmanship Quality of Photovoltaic Modules Adhesive strength before and after aging Pull-off force [N/cm] 190 130 210 210 120 150 220 140 Test 1 Test 2 Test 3 Test 4 Adhesive strength of similar samples Samples from modules with similar design 250 200 150 100 50 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Pull-off force [N/cm] Unloaded After moisture/thermal treatment There is no prescribed minimum adhesive strength. But: Great variation between samples of same type. Change due to climate load is a distinguishable quality criterion (here 30% 40%). 4
Assessment of Workmanship Quality of Photovoltaic Modules Encapsulation material (EVA) is removed from the module (destructive test). Non-cross-linked material is "washed out" with solvent. Procedure is used at manufacturers and investors to check the quality of lamination. Values are usually between 68% and 90%. Low values indicate defects, which will most probably lead to delamination. Comparison identifies isolated cases in certified module types as well. With consistent quality, problems tend not to occur during certification but during implementation. 100% 90% Level of cross-linking (values sorted into module types) 2012 2013 / 23 manufacturers / 36 module types 310 individual samples (at least two samples per module) 80% 70% 60% 50% 40% 30% 20% 10% 0% 5
PV+Test: Independent Module Test from TÜV Rheinland + Solarpraxis Main criteria and weighting 10% 5% 25% Tests go far beyond the IEC requirements. Tests are financed by the module manufacturers themselves. Modules are purchased anonymously on the market. Manufacturer decides whether the test results are published in "pv magazine": "Best of" list. Excellent instrument for observing the market. 15% Safety Resistance to aging Power output Documentation Workmanship Warranties, other 25% 20% Score (published by 12 out of 21 companies) Modules tested Very good Very good (-) Good (+) Goo d Good (-) Satisfac tory (+) Satisfac tory Adequ ate Poor Test plan Standard before 2012 New standard 19 1 3 6 5 1 0 2 1 0 2 1 1 Total 21 2 3 6 5 1 0 3 1 0 www.pvtest.de 6
Optimizing (Photovoltaic Module) Energy Yields 100% 99% Relative energy yield 98% 97% 96% 95% 94% 93% 92% 91% 90% # 1 # 2 # 3 # 4 # 5 # 6 # 7 # 8 # 9 # 10 # 11 # 12 # 13 # 14 Module type ~ 5% Compare (module) technologies and products (1 year) Measure energy yield in different climate zones Maximize energy yield depending on location 7
Photovoltaic Systems: Fault Statistics from Acceptance Results from 125 large-scale systems analyzed and inspected. 20% show serious defects (direct action required). Further 10% demonstrate high error rate. Around 50% of defects in the individual segments are installation errors. Other 14% 18% Planning More than 1 GWp checked to date Inverters Connection boxes 13% Support frame 11% 25% Modules Grounding, lightning protection 5% 14% Cabling 8
Photovoltaic Systems: Fire Risk 180 incidents of heat and fire damage, of which 65 caused by photovoltaic systems Severity of damage Causes of faults Unknown Inverters Total damage 10 21 21 Building System Components 49 56 65 DC plugs DC switches 5 4 6 Connection boxes 9 20 14 AC distribution 34 PV modules Source: Research project on preventive fire protection in photovoltaic systems At least 50% of faults relate to installation. 9
Photovoltaic Systems: Preventing Quality Defects Poor system quality must be prevented because a widespread discussion of acceptance is anticipated. It is harming the technology and its prevalence. Acceptable systems must be further optimized economically and ecologically. Safeguarding investors' profits is paramount. 10
TÜV Rheinland: Solar Quality Road Map The objectives Obtain social acceptance of solar energy Establish solar energy as a reliable part of the energy transition in the long term Stabilize the solar industry in Germany The module technology Improve quality in production Observe the market: Expand comprehensive comparison tests for modules available on the market Critically assess apparently cheap solutions in module technology and testing Develop and establish new, practical tests for special applications as well The photovoltaic systems Large-scale projects: Independent acceptance and certification as well as periodic checks/monitoring Improve the quality process in the key project steps Planning, transport, installation Accompanying module tests for assuring quality directly in the project Qualify specialist installation companies for small systems Regularly maintain small systems Raise public awareness: Greater attention to quality among consumers, investors, banks, insurance companies, operators 11