Stion Corp of San Jose, CA, USA says that its CIGS (copper indium gallium selenium) photovoltaic module has passed the 'Thresher' test performed at the Renewable Energy Test Center (RETC) in Fremont, CA.
The Thresher test is intended to simulate at least 25 years of real-world exposure to evaluate long-term durability and performance. Harsh conditions induced over a six-month period expose the modules to damp heat, humidity, freezing and dynamic mechanic load. To date, less than five of the world's top 30 photovoltaic module makers have passed the thresher test.
The Thresher test consists of four individual tests during which modules undergo rapid temperature changes from as much as 194°F (90°C) under 85% RH (relative humidity) down to -40°F (40°C):
The Humidity Freeze test consists of five different sub-tests including a UV soak, 50 hours of thermal cycling and 30 humidity freeze cycles; The Thermal Cycling test consists of three different sub-tests including a total of 600 cycles, during which STC peak power current is simultaneously applied. The Damp heat test consists of two different sub-tests for a total of over 2000 hours of continuous damp heat (at 85°C and 85% RH). The Dynamic mechanical test consists of three different sub-tests that test Stion frameless clamps by applying 1000 Pa of downward and upward pressure over 1000 cycles that last 30 seconds each.
Post-testing degradation levels were well below the threshold limit needed to pass the thresher test, notes Stion.
"The thresher test is the most demanding test in the industry and has been difficult for even the largest solar manufacturer's to pass," says chief technology officer Bob Wieting PhD.
