SunPower's E20/327 PV module has survived the rigorous 'Atlas 5+' PV durability testing programme and demonstrated a power degradation of less than 2%, the company has revealed.

The Atlas 25+ testing protocol is said to include long-term environmental exposure that requires modules to have less than 8% degradation over the testing period in order to receive SGS certification. This reflects the environmental degradation stresses that can be expected over a long-term period in the field.

The programme is designed to expose modules to a series of stresses, including UV-A/UV-B exposure, salt spray corrosion, condensing humidity, solar/thermal humidity cycle, solar/thermal humidity freeze cycle, Arizona and Florida solar tracking – including peak summer – and initial, final and multiple interval measurements.

Richard Slomko, global testing manager at Atlas Testing Services said: "Our Atlas 25+ third-party testing programme replicates harsh weather conditions that solar panels will undergo during their lifetime. We are pleased that SunPower's high efficiency solar panels not only withstood these conditions, but well exceeded the power degradation criteria of 8% in addition to testing well on all criteria. We are delighted that SunPower has received outstanding results from our Atlas 25+ programme."

The SGS test is not a standard that all PV modules have to meet and other testing houses provide their own versions of testing for module manufacturers that go beyond internationally accepted testing.

The Atlas 25+ testing protocol is a proprietary multi-dimensional durability test programme.