400 watts of solar on roof

[Lcavalletti]

My roof is now a serious energy maker with 400 watts of solar on the roof, two 100 panels mounted to roof racks, and 2 - 100 panels mounted to the hardtop front and rear. With this much power I can have hot water, a cold fridge and my vent running 24/7

other components include a 300 AH LIFEpo, renogy solar controller, dc to dc charger and 3000 watt inverter.

You can see my new Aus J 12 Volt water heater in the bottom corner there. Works amazingly well and uses very little power.

My concern with panels on the roof was not being able to put surf boards and rafts up there without touching the panels. so the panels all sit lower than the rack by design

[N147JK]

That is awesome - a lot of power. Question about the mounts.. I'm probably overthinking this, but should the Z-mount brackets be on the long side of the panel, the short side, or does it matter? The way you have yours on the left and right sides, there's a bit less aerodynamic drag. My panels will have to go on long side across the roof, same as yours. - Thanks

[Lcavalletti]

the panel is mostly tucked behind the major area of wind resistance as the CCV high top that you see them mounted to protrudes up a bit at the front, acting as a wind fairing. I have the front and rear panel mounted with your standard Z brackets, ( dont use the Renogy Z brackets) they were a thinner diameter aluminum than the standard made in China ones I found on amazon.

I used Marine 4200 to seal the brackets to the roof and 2 screws per bracket with 4 total brackets. , so they should be on there permanently, without issue, The brackets are all at high spots on the concave roof, so there shouldnt be any standing water where the brackets sit.

I believe the front panel has brackets on the long side and the rear on the short side ( in rear and long side in front) Had to do this to keep all the brackets in the high spots. . .

[N147JK]

OK thanks for the good info. Do you have a link to the brackets on Amazon?

[N147JK]

I found the following in the installation manual for the Renogy Z brackets:

3) If using a panel oriented such that the distance between Z-Brackets along an edge exceeds 39 in
(1 m), it is advisable to add Z-Brackets for mid-span support. Lack of mid-span support can cause
excessive stress in the module under load and may result in solar module damage.

So I guess that answers my question.

[Lcavalletti]

so the front panel is a new 9bb panel at 38" inches long, so Im probably pushing it not having a center support. I guess well see if its up there securely only time will tell.

[N147JK]

Kind of a pain to install at this point, but could you add a center Z-bracket that faced rearward? That is, turn the bracket around so that the flange contacting the roof would be under and behind the panel edge. That might enable you to have one in the center along that leading edge.

I'm going to use VHB tape only, but, also install a safety tether made of stainless safety wire. The wire will be secured to the roof vent assembly and hopefully hold the panel, just in case the brackets ever come loose (heaven forbid).

[Lcavalletti]

hmmm, I could install a straight 90 degree bracket by drilling a hole through the front center of the panel frame , that would give me additional support in the center, probably worth while doing having one more hole in the top for safety.

[Twoxentrix]

Have you considered using a front wind deflector? wide variety available, or could make your own (or altar an existing one a little to make it work) .
https://www.amazon.com/Kargo-Master-...0-4513d670b6bc

[boywonder]

Nice..I have a pair of 100W renogy panels and was going to add a couple more, but ended up buying one 400W panel to replace them...it saves me about 16 lbs on a manual SMB penthouse top.

Have you done the math to see how well the different panels play together? Sometimes you can get really close to 100% efficiency if the panels have similar specs.