CNPV Solar Power advised that it had refined the positive tolerance practice for its solar PV modules. The company noted that it routinely provides its solar modules with a positive tolerance based off the solar PV modules rating label. Previously, CNPV provided modules with a +/- tolerance as is traditional industry protocol, which committed to a larger tolerance than its operational activities. CNPV’s positive tolerance process was effective as of November 1 with all modules manufactured at its facility contractually ensured to provide the three positive gains advertised.
Bypina Veerraju Chaudary, CNPV's COO explained the company’s decision in greater detail, “As a result of a more stringent, tighter tolerance cell selection process, our module production delivers three key elements of major benefit to our customers; the cell power balancing for module longevity and increased harvesting ability, the module balancing for additional power gains in the order of 2% and the ability to always supply at least the value of the invoiced power rating. Our focus on delivering improved benefit in these and other areas has ensured that we have always provided the positive aspects of these topics. As of today we have broken from the industry standard and formalised our position that all modules will be of equal or greater power output than the rating label up to a maximum of 3%. Within this +3% tolerance, we have a further segregation of power outputs; we carry out sub-binning based upon the Imp (maximum power current), to ensure that each module is within 1% of its collective neighbours within the pallet. And finally, our primary binning, for cell selection, utilises a greater sorting ratio than our competitors, which ensures that each individual module's cells are balanced with a significantly higher tolerance reduction. Tighter tolerance has a major impact on the power harvesting and longevity in real world applications and is independently shown to be a major benefit to the customers goals of profit generation. “
The company noted that contrary to an some individual’s beliefs, the positive power tolerance does not fall under the “bigger is better category.” Instead, a -3%+3% tolerance has a 6% potential variation, but by using 1% sub-binning for the modules, the latent module mismatch within the pallet/string is cut from 6% to 1% with a result net effect of 2% gain on power harvesting.