The verification of the Solar Keymark certification delivered by SP Technical Institute of Sweden has now been completed. Due to uncertainties in the original process of measuring the performance values of Arcon-Sunmark’s collectors, a risk of inaccuracy in the original test results has been identified. However, witnessed by a neutral third party auditor, SP Technical Institute of Sweden has conducted new tests which have validated the results of the original test:
“We conclude that the differences between previous and new performance test results are well within the laboratory’s measurement uncertainty and thus well within the 10% limit according to the Solar Keymark scheme rules. Consequently SP Certification’s decision is that the four current certificates; SP SC0840-14, SP-SC0841-14, SP-SC0842-14 and SP-SC0843-14 including their contents are valid.”
Arcon-Sunmark appreciates the effort done by the parties involved, in particular the teams of SP Technical Institute of Sweden and TÜV Rheinland Energy GmbH.
To benchmark performance the solar panels are submitted to outdoor tests, under quasi dynamic conditions. The power output is then calculated using a multi linear fit to the recorded data. The output is the final number of thermal coefficients. Due to measurement uncertainties in the process two tests can never be 100% identical – there will always be deviations. However precision and transparency are indispensable values of Arcon-Sunmark. Therefore Arcon-Sunmark has requested – despite the verification of the existing certifications – that SP Technical Institute of Sweden issues a new set of certifications on behalf of Arcon-Sunmark. The updated certifications will include updated thermal coefficients based on the verification results. Despite that the variations between the two tests have been deemed minor, Arcon-Sunmark insists that it is in everybody’s interest to issue new certificates as soon as possible. The respect for and the importance of the Solar Keymark certifications outweighs the inconvenience of this decision.