A Down Side to String Inverters

[BruceM]

A roof system using the backside of the PV panels for hot air heating could be an interesting cogen system but when you need the heat, it's cold and your losses from the front surface would lower temperatures terribly.   The panels would need to be redesigned so that the cells moved back from the glass, having a trapped air space to reduce losses through the glass while allowing the heat to be collected from the back. (Back only to avoid dust on the PV cell surfaces.) 

Best suited to a large flat commercial roof, I suspect, due to large air duct issues. 

[LowGear]

I don't want carlb laughing too hard but I did get up to MEL (Menehune Energy Lab - a tru TLA) yesterday which has the two strings of panels on the roof - Properly mounted I might add.  Sometimes doing a nice job is worth the dollars.  You may not remember that carlb informed me about the internal fuses.  I was so excited when string #2 fuse was indeed blown.  I switched in one of the unused and tested to work fuses but put it in the wrong holder.  Yeah, mr. blind man leading failed to notice that #2 fuse holder was up there in the hard spot and not over in the easy to work place.  One of my personal mantras is "No glasses - No tools".

I am not inviting multi-page rants about the climate but this has been the wettest - coldest January, February & March we have witnessed since immigrating to Hawaii in 1999.  (Weather - Okay)  I bring this up because I'll be lucky to get 5 or 6 KW out this 6 KW inverter for the whole day.  These months usually have 25 KW days and every once in a while poking past 30 KW (Okay, barely).  30 is worth almost $10.

Carry on.

[LowGear]

It's about noon on a somewhat overcast day.  Where you can see shadows but sun glasses would be over dressing.  Got up to MEL and there it was.  5,7nn Watts and the cooling fan humming right along.  Thank you again carlb.  Glasses are just as important as fuses.  I even found the extra fuses I bought off eBay for a couple of bucks each.  A nice day here at Camp Aloha.

Casey

[Carlb]

so i guess it is working correctly now?   Those fuse holders definitely require glasses to spot for anyone over 55 years old.   If you have big hands like me that are also a pain to get to.  Hope you array is working ok now. 

[Carlb]

nice sunny cool day here yesterday,   Both of my 5kw SMA  inverters were humming away at 5100 watts each much of the day.

[LowGear]

Checked out production yesterday at about 5:00 PM.  22 KWH but the sun actually came out and said hello. 

Yes, all is well in MEL land.

Thanks,