The solar industry needs more comprehensive reliability testing standards for modules, according to participants in a webinar hosted by manufacturing industry body SEMI.
Participants in SEMI PV’s The convergence of PV materials, test and reliability: what really matters? discussion heard almost a quarter of PV modules carried defects once out of the packaging, according to data from consultants SolarBuyer.
Amid fears that the race to the bottom in cost terms is encouraging module manufacturers to cut corners, Conrad Burke, of U.S. chemical company DuPont, told the webinar the module reliability assumptions of investors were far short of actual performance.
Burke said U.S. performance figures indicated a 5% annual power degradation from modules whereas financial models are based on only a 0.5% annual figure, a disparity which, according to Burke, adds up to a 60% or more reduction in expected net present value versus plan, for solar projects.
Sarah Kurtz, of the National Renewable Energy Laboratory (NREL), said the figures proved the existing International Electrotechnical Commission (IEC) standards are insufficient and do not accurately predict performance in the field.
NREL colleague John Wohlgemuth invited solar industry representatives to sign up to international PV material Q&A task force groups for standardizing several aspects of module performance and testing.
The nine Q&A standardization groups address: PV manufacturing similar to ISO 9001; thermal and mechanical fatigue stress levels; humidity, temperature and voltage stress levels; diodes, shading and reverse bias; UV, temperature and humidity; communication of PV QA ratings; wind and snow loading; thin-film module testing; and CPV testing.