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Hi folks, I have a new 4.0 KW DC (STC) array that was approved for PG&E interconnect two weeks ago and switched on for about one week now. Panels are 16 250W REC Solar units with Enphase M215 microinverters on nearly south-facing roof. I'm in the Northern Cal Bay area.
I do have some morning and afternoon shading from nearby trees including some year-round coast live oaks that drop occasional leaves, so I was up on a stepladder to blow the leaves off and up close to the nearest panels. I noticed from a few inches away that the actual blue solar cells have a splotchy, mottled coloration of darker and lighter blue, almost like hard water stains. I see no evidence of actual condensation under the glass, and the pattern looks like it is on the cells, not on the outside or inside surface of the glass above the cells. Is this just the polycrystalline structure of the solar cells and normal? I've never looked at PV panels up close before.
In the first day or so I was able to check the output on the Enlighten website on a sunny day, and production was slightly above PVWatts projections (actual derate factor of 0.8, vs 0.76 assumed by PVWatts) for the brightest days. So the panels seem to be producing to spec. Unfortunately now I'm hitting the two months of the year where the sun ducks behind neighbor trees for much of the day, so between that and clouds I've not been able to re-verify the output on a sunny day.
I do have some morning and afternoon shading from nearby trees including some year-round coast live oaks that drop occasional leaves, so I was up on a stepladder to blow the leaves off and up close to the nearest panels. I noticed from a few inches away that the actual blue solar cells have a splotchy, mottled coloration of darker and lighter blue, almost like hard water stains. I see no evidence of actual condensation under the glass, and the pattern looks like it is on the cells, not on the outside or inside surface of the glass above the cells. Is this just the polycrystalline structure of the solar cells and normal? I've never looked at PV panels up close before.
In the first day or so I was able to check the output on the Enlighten website on a sunny day, and production was slightly above PVWatts projections (actual derate factor of 0.8, vs 0.76 assumed by PVWatts) for the brightest days. So the panels seem to be producing to spec. Unfortunately now I'm hitting the two months of the year where the sun ducks behind neighbor trees for much of the day, so between that and clouds I've not been able to re-verify the output on a sunny day.
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