Maxeon Solar Cell Vs.
      Conventional Solar Cell
                 Maxeon Solar Cell (Back)                                            Conventional Solar Cells (Front)
                                                      Thick                                                                    Thin lines of
                                                      copper-plated                                                            baked-on
                                                      foundation                                                               metal paste
                                                                                                                               Soldered copper 
                                                      Strain-relieved                                                          ribbons
                                                      copper bar 
                                                      connecting                                                               Ribbons 
                                                      cell-to-cell                                                             connect
                                                                                                                               cell-to-cell
    1. Thick copper (tin-plated) is robust against corrosion.                 1. Very thin screen-printed metal lines on the front of the cell are 
                                                                                 susceptible to corrosion over time
    2. No soldering along the length of the cell
                                                                              2. High-stress solder joints between the long copper ribbons and 
    3. Copper bar connecting cells has robust copper-to-copper                   the crystal solar cell
       soldering, strain-relief, and double-redundancy.
                                                                                   • As the panels get hot in the day and cold at night the copper 
    4. Solid copper foundation maintains the cell energy production                  expands but the silicon cell does not.
       even if the silicon cracks. 
                                                                                   • Over time, this repeated stress causes cells to crack and 
                                                                                     solder bonds to break.
                                                                              3. Single points of failure on copper ribbons between cells.
                                                                              4. Screen-printed metal paste has no strength to hold the   cell 
                                                                                 together when the silicon cracks
      Cracked Standard Efficiency Cells in the Field
                                      Conventional Panels                                                            SunPower Panel
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                                                                                  B
      Likely damaged in installation     Likely damaged from               Left side has broken copper              Even with a crack, all parts of 
      or from repeated hot/cold          poor soldering process and        ribbons between a pair of cells.         the cell are running (no black).
      temp cycles                        hot/cold temp cycles.
      Conventional panels commonly fail from hot/cold temperature 
      cycles that crack solar cells, solder joints and copper ribbons 
      over time.
     Common Ways Conventional Solar Cells Degrade
                                                  
                                                                      Corrosion
                                                                      Cell or Interconnect Breaks
                                                                      Output Lead Problems
                                                                      Junction Box Problems
                                      Corrosion                       Jbox Delamination
            Cell or                   45.3%                           Overheated Wires, Diodes, 
            Interconnect                                              Terminal Strips
            Breaks                                                    Mechanical Damage
            40.7%                                                     Defective Bypass Diodes
    Wohlgemuth, J. “Reliability of PV Systems.”
    Proceedings of SPIE, Aug, 2008.
     Unmatched Reliability:
                                                                                                    Cell or 
                                                                                                    Inter-
     Unique MaxeonDesign                                                                            connect 
                                                                                                    Breaks
     • No cell-to-cell interconnect breakage
     • Cell cracks have essentially no impact on energy output
         105%
         100%                                                                         SunPower (Current)
      n
      o
      i
      t  95%                                                                          Conventional Modules
      a
      d
      a
      r
      g  90%
      e
      D
       
      r
      e  85%
      w
      o        Certification
      P        Standard
         80% 200 Cycles
         75%
             0           500          1000         1500         2000         2500
                   Number of Cycles: -40 to 85C (-40 to 185F), 5 cycles per day
    The unique design of the Maxeon cell makes the                                      Non-SunPower data from Koehl, Michael, et. al. 
                                                                                        “PV Reliability: Accelerated Aging Tests and 
    Panels impervious to hot/cold temperature cycles.                                   Modeling of Degradation.”  Fraunhofer ISE and 
                                                                                        TUV Rheinland.  Presented at EUPVSEC, 
                                                                                        Valencia Spain, Sept 2010.
        Unmatched Reliability:
                                                                                                                                                                               Cell or 
                                                                                                                                                                               Inter-
        Unique Maxeon Design                                                                                                                                                   connect 
                                                                                                                                                                               Breaks
        • No conventional panel data is available for comparison for the
            world’s most challenging accelerated test: cycles of hot-and-humid 
            followed by rapid freezing – that design cannot survive.
        • The certification standard is a challenge for most panels at 10 cycles.1  
            SunPower panels are almost unaffected after 280 cycles.
               100%
               90%                                                                                                      SunPower (Current)
                                                                                                                        SunPower (Previous)
               80%
           n   70%
           o
           i
           t
           a
           d   60%
           a
           r                                                                                                    For certification testing: “The top 4 
           g
           e                                                                                                    failure rates for c-Si modules were 
           D   50%
            
           r
           e                                                                                                    related to damp heat, thermal cycling, 
           w   40%
           o                Certification                                                                       humidity freeze and diode tests.”1 
           P
               30%          Standard
                            10 Cycles
               20%
               10%
                      0            50          100           150          200          250           300
            Number of Cycles: -40 to 85C (-40 to 185F) with ice and humidity, 1 cycle per day
       The unique design of the Maxeon cell makes the 
       Panels impervious to water-freezing cycles.
                                                                                                                                                1  TamizhMani, B. G. “Failure Analysis of Module Design 
                                                                                                                                                  Qualification Testing – III,” 36th IEEE PVSC Conf, 2010.