Solar roof mounting

[mojavemike]

quote:Originally posted by WorkerB

Hi Mike,
As Hamrad said earlier on this post I added 6 panels to the Monty a few days ago. Since installation I have not had a perfect day of sunshine so I can't speak from experience. We had one fair day since installation and I was excited to see my 4 AGM batteries fully charged in 4 hours. The rest of the day ran the inverter, 5 cu. ft. freezer 2 laptops, electric coffee pot, printer, lights, TV & Satellite receiver. These were use as needed but not all at once. I will post some pictures later today. We are at Quartzsite and need to run to town. The cost was reasonable but I shopped around and found great deals. Some folks like to save the money and do it themselves. Others pay more and have their system installed. Either way you will not be sorry you installed solar. We may still be here when you arrive so keep in touch and you can climb on the roof and have a look. Regards,
John

John, That sounds great! Would be nice to see your setup. Haven't recieved word yet on when our Monty will show up here. Sure getting the rain now. Thanks, Mike

[mojavemike]

quote:Originally posted by mojavemike

John, That sounds great! Would be nice to see your setup. Haven't recieved word yet on when our Monty will show up here. Sure getting the rain now. Thanks, Mike

John, just got word that my Monty won't be here until the 3rd week of February. Appears that other besides me are starting to spend their money. You will probably be gone by then. If you are heading this way, I have plenty of room with a view, for a stop over on where ever you are going. Mike

[7.3Ford]

quote:Originally posted by HamRad

Mojavemike,
You should be here at Quartzsite. John, WorkerB, and the Q group are installing 6 panels on his rig. They made great progress yesterday and will probably finish today. He should have all the power he can use once they get the panels all dialed in. Hopefully there will be some pictures.

We are all still waiting on pictures, would love to see how you did your install.

I hope to have all the parts in two weeks. I went with two Uni-Solar PVL 136 Watts and two 68 Watt panels (four 136 Watt panels wouldn't fit). These are the ones that sick to the rubber roof. The reason I went that way, was they are the only panel that is shadow tolerant, and we camp around trees a lot. There is an outfit that use the 68 Watt panel, and put a nice rubber edge around it that you screw into the roof, but the price is three times as much. The panel is rated for 130 miles per hour, so I don't think you really need it. Time will tell, but getting the roof clean is paramount.

[lasater]

7.3 Ford. I went the same way with 2 68 watt panels. We only run a few lights, the refer, and DW's laptop with our system. However, we run the laptop on battery for a couple of hours then plug it in and charge it for a couple of hours. That way, I still have enough power left in the batteries to run my 750 watt coffee pot in the morning. The coffee pot was the main reason for going with solar. Not polite ot crank a generator too early.

[7.3Ford]

quote:Originally posted by lasater

7.3 Ford. I went the same way with 2 68 watt panels.

How long have you had them on there, and have you had any problems.

I know others express concern when I was researching, and was already to go with Glass panels, til I found out that if as few as three cells in the panel got shaded, it could knock out the whole panels output. This is because most only have three by pass diodes, where the Uni-Solar has a by pass diode on each cell.

[lasater]

Had them put on at Q this year. No problems at all with them. I do check the batteries pretty often to make sure they have plenty of distilled water.

[WorkerB]

Mike,
I came across this thread again and something I missed in your question should be answered. You asked about attaching the panels. My research turned up that you want to use stainless screws when attaching the panels. If you have ever seen a rusty screw in plywood it is not a good thing. I used #10 stainless steel pan head screws. 1 1/4" long. First I located the roof trusses and attached the front panel legs. The back legs only screwed into the plywood wherever they landed. Dicor on the roof then the legs then more Dicor to finish. By having a solid attachment at the leading edge of the panels wind won't be a problem while driving. Hope that helped. BTW the pictures taken of the installation are general in nature. Nothing specific as to the mechanical connections or wiring. Here they are.
John

[WorkerB]

quote:Originally posted by 7.3Ford

How long have you had them on there, and have you had any problems.

I know others express concern when I was researching, and was already to go with Glass panels, til I found out that if as few as three cells in the panel got shaded, it could knock out the whole panels output. This is because most only have three by pass diodes, where the Uni-Solar has a by pass diode on each cell.

Mike where did you get the info about the diodes? I would like to look into that.
Thanks,
John

[7.3Ford]

quote:Originally posted by WorkerB
Mike where did you get the info about the diodes? I would like to look into that.
Thanks,
John

John,

I read it a couple of different sites... I did a Google and found this link to a lab exercise.
http://www.learnonline.com/pdf/The%2...l%20Output.pdf

Easy way to tell is look at the spec sheet, and look for how many diodes are in the panel. If a panel has 60 cells and 3 diodes, then you would have 3 parallel circuits of 20 cells in series. If just three cells are shaded (one in each of the series) the whole panel is 0 output. See PDF above near end, explains it.

Now the Uni-Solar has a diode on each cell, so you will lose a .5 volt (drop across the diode) for each shaded cell, but doesn't cause an open circuit.

I think the links where I was reading are on my other computer, which is not started... I will post the those URL's.

PS, thanks for posting the pictures. My panels shipped today, will be here next Tuesday.

[7.3Ford]

John,

Here another link, this one is by Kyocera, when I was looking at there 205 Watt Panels.
http://www.kyocerasolar.com/learn/modules.html#shading

Here is something from Norther Arizona Wind & Sun, see "Are some panels more shade tolerant?" about halfway down.
http://www.windsun.com/Photovolaic_S..._solar_faq.htm