2 double DIY 72 cell solar panels and one single 36 cell panel on roof

[Thomashamka]

Hi, how did you connect these? Is this 24 volt system or 12 volt? As i got cells for one 72 cell panel and one 36 cell panel and im thinking if i should do 3 - 36 cell panels or the 72cell and 36 cell panel.

[wiboater4]

@Thomashamka It depends on the type of charge controller you have. I have a 500 watt MPPT controller. I have a 12 volt battery bank. The 72 cell panels are in series for 24 volt and the 36 cell is 12 volts. The controller brings them all in at 12 volts but ups the amperage so nothing is wasted. It is a BZ charge controller.If you have a large enough glass to do a 72 cell go with 72 cells, My other panels are 60 cell panels on the garage using enphase inverters.

[Thomashamka]

@wiboater4 Could you tell me what kind of cable did you use FROM the solar panel?

[wiboater4]

@Thomashamka I bought junction boxes with cables from everbright solar on Ebay.

[sdbvideo]

Air bubbles... would it be somehow possible to put resin on the cells 1st and than (maybe after a little drying time) put them in the resin bath that is the front glass.?

[wiboater4]

@sdbvideo I have the bubble problem pretty much solved now . look at the other video's showing the laminating oven I use and I use EVA now instead of the Sylgard. Also on the larger 4 panels on my garage roof the one that looks the worst with the most air pockets on it actually puts out the most wattage. I'm probably not going to build any more panels because I think it cost almost as much to build one right as it does to buy one.

[sdbvideo]

@wiboater4 Yeah i was a bit afraid of that, costing more than (and not even counting the ours work).

But well its a nice experiance to make one that exualy works;)

I thing im going to buy the panels and break my head over a very light trackingsystem, i beleive that those make greet sence.

Good luck with your projects!

[wiboater4]

@sdbvideo The tracking setup is worth it if you build your own. They want to much for the commercial ones. 

[wiboater4]

yes , in April the 2 larger panels on garage roof that aren't shown on here yet produced 39 KWH's even without the tracker . That isn't counting the ones on the house roof shown here. They probably put out close to the same but I don't have the Kill a Watt meter on them right now because they feed into my battery bank. I expect to get more this month because of better sunlight and adding a tracker.

[zackbridgman]

realistically before i invest in doing a similar set up have you noticed a change in your electric bill using a grid tie inverter??

[wiboater4]

they are completely covered in sylgard 184 so they are protected on the back with that. It's clear so you can see thru it so it looks like there isn't anything there. I've built 2 more larger panels 78" X 35" That I did with Tedlar on the back like the factory ones.I used EVA on those too instead of sylgard because it was cheaper.

[Cedarworkshop]

Hi, what were you going to use for the backing?

[wiboater4]

I went up and checked the sells, each one is putting out 20 volts. I checked kind of early in the day( not full sun) and got 48 watts from the small one with the thicker 1/4 tempered glass. The other 2 doubles each checked out at 55 watts for each half of the panel. So they are all consistent. The cells were supposed to be 2.4 to 2.6 watts each. I'm sure there is some loss thru the glass and I tested with a grid tie inverter and a kill a watt meter. so there is loss there also

[wiboater4]

The mounts are lag bolted into the roof. I tried to hit the rafters but am off on some on one side. I'm going to add a cross piece inside later for extra strength. The roof is pretty strong though because it's an older house with boards on the roof instead of blandex.

[wiboater4]

Make that 13 volts.

[sjh7132]

12A at how many volts? How did you attach to the roof so that they don't get yanked off in a high wind? Nice job!

[wiboater4]

@sjh7132 Just checked it now, not full sun about 10 amps and 13.5 volts while feeding into the battery bank. This is with a meter with a needle not a digital readout so I'm probably off a little. I'll be testing the panel output later for open voltage in full sun for each panel seperatly.

[wiboater4]

Thanks, I have to modify the upper mount attachment a little so I can tip them up a little more for winter.

[michael970]

Very nice setup .I cant wait to see them tracking great mounts.I hope they work out great for you.TAKE CARE