CNPV Formalises Positive Tolerance Gains For Modules

CNPV Solar Power SA, has formalised their on going practice of providing their solar photovoltaic modules with a positive tolerance.

CNPV, routinely supplies their solar PV modules with a positive tolerance based upon the solar PV modules rating label. Their historical written commitment has been to provide modules with a +/- tolerance as is common industry practice. The previous written commitment has a wider tolerance than their operational activities and is therefore being repositioned to reflect their ongoing commitment to provide increased value for large area modules.

Mr. Bypina Veerraju Chaudary, CNPV's COO explained 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. " 

There is a counter-intuitive element to this feature, sometimes based on individuals perception that a bigger number is a bigger benefit. In the case of positive power tolerance this is not the case. A -3%+3% tolerance has a 6% potential variation. By utilising 1% sub-binning for the modules, the latent module mismatch within the pallet/string is reduced from 6% to 1% with a resultant net effect of a 2% gain on power harvesting.

CNPV modules will continue to be supplied in line with their strategy of providing the largest possible financial gain for the capital invested when utilising crystalline photovoltaic technology. The formalisation of the positive tolerance process warrants that as of November 1, 2011, all modules leaving CNPV's manufacturing facility are contractually ensured to encompass the three positive gains noted.