I'm a solar designer and contractor and my friend Pete asked me to post to this forum.

I've decided to write about the new Sharp 165W STC panels. The Sharp panels are a solid price/performance product. They are equal in quality to Kyocera, but not at the same level as Siemens (now Shell), BP Solar or Astropower. Also, if these are to be used with a Sunny Boy 2500W inverter (9 panel strings), be warned that the input voltage may drop below the inverters MPPT threshold on hot days.

Otherwise, aggressively shop the price and you will find one of the lowest $/W products out there in a reasonable quality package.

I was speaking with John Bernder (SMA) and he expalined that the lower cost was due to the solar-cells are thinner than even the Kyocera panels.

Does sharp have any reliabilty data on these new puppies ??

My KC-120's have been flawless for a year now

Also .. 9 panels seems small for an SB2500U ... the minimum number of 12volt panels that can run here in florida is 20 ... below this and the array voltage underload goes below 240VDC. I ***ume the sharp panels are 24Volts ?

Yes, the Sharp panels are 24VDC nominal. Open circuit is about 41VDC and under load you'll see about 35VDC. However, on hot days, we will see the 9 string voltage drop to the low 240's. Recall that the Sunny Boy likes to see a min. of 250VDC and their MPPT algorithm will cut out before the unit does, usually around 244VDC.

Yesterday I measured the mppt at 12.75
volts (51 volts , on the 4 panel string). So I am agreeing with you and the 18 panel (or 9 for the sharps) is a definite no no for warm climates !!


I guess I should start a thread in the SMA section on this one !!

Acording to www.sma-america.com website string sizing sheet I should use 10-12 of these panels. Maybe 9 just isn't enough.
The temperature I used was 23'-113'F as the ambient temperature for my location.