What does the term "tolerance" mean, when used regarding PV panels?

Is 5% tolerance better than 10% tolerance, or just the other way around?


  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: "Tolerance"

    that is basically the deviation from the manufacturer's specified wattage output and is given in a + and - percentage. when no + and - is given then the percentage given is automatically for both + and -. for example a 100w pv with a 10% tolerance can vary +10w(+10%) and - 10w(-10%) from the 100w given by the manufacturer making it range from 90w to 110w straight from the factory. this also means that the manufacturer can legally pass off 90w pvs for 100w pvs with severe doubts 110w pvs will be allowed out of the door as 100w pvs. the 5% tolerance would be + or - 5w from the 100w specified giving a range of 95w to 105w. for those giving + and - %s the +% means added to the original wattage and the -% means subtracted from the original wattage. i hope you understand now.
    in addition, most pv manufacturers use the standard irradiance of 1000 watts per meter squared and is incorporated in stc ratings.
  • System2
    System2 Posts: 6,290 admin
    Re: "Tolerance"

    Thanks, Niel.

    I do understand, now.