Solar

[Blue~Go]

I prefer a design like that to the Z brackets - and in fact my home-made (well, home designed and farmed out) brackets are somewhat similar. Having the top part of the foot attach to the bottom edge of the panel rim is a plus, because that's where any stock holes usually are, and you can drill others. Often (always?) the "side wall" is a dual-thinner-walled construction.

One difference on mine is that a Rivnut will go into the base part of the foot, so then there won't be a nut/wrench needed on the "back side" when putting them together. But it's the same principle.

[HoosierB]

Yep, I had the same thought. What about something like this?...no tools needed...

[Blue~Go]

I'm not sure I see how those last ones work. Is there a second piece? But regardless, I think we're on the same page. Even if you never plan to tilt your panels, there are times you might want to clean under them, check wiring connections, or etc.

I also think that the stock panel could have had a bit more air space under it - some mounts put them pretty close.

I did an experiment where I set two of my glass/aluminum panels on the roof on wooden blocks at the corners, a different height for each panel. I compared panel temperature, roof temp under the panels vs. open roof, and ceiling temp inside. The gist was that I felt it would be best to have them at least 1-1/4" above the roof (the bottom of the frame at the lowest point, not the back of the panel section), and more would be better. Less than that trapped a lot more heat. This was done on something like an 75º sunny afternoon.

[HoosierB]

Is there a second piece?

Yes, similar to that other 2-piece bracket, but with a thumbwheel knob/screw (no-tool needed).
This one would also appear to have the necessary height adjustment you're referring to.

With 1 1/4" or more air space between the panel and roof surface, would you need an air dam in front of the panel to eliminate any "lift" potential?

[Blue~Go]

Yes, similar to that other 2-piece bracket, but with a thumbwheel knob/screw (no-tool needed).
This one would also appear to have the necessary height adjustment you're referring to.

Ah, okay, I see. I would wonder how much you have to "clamp" it to keep it from moving in the slot (mine will just have one hole once I decide on the exact height). Maybe it'd be fine. (The AM Solar brackets have multiple holes for adjustment, but no slot.)

Not sure what they are made of, but one thing to be aware of (you may already be) is that stainless on stainless can gall. Meaning they sort of fuse together; not fun. You can use a product like Tef Gel on the threads to prevent this, which is fine if you are only going to install once and move them seldom, but kind of a messy pain for doing/undoing on a regular basis.

With 1 1/4" or more air space between the panel and roof surface, would you need an air dam in front of the panel to eliminate any "lift" potential?

You would think so, but in reality that doesn't seem to be the case. I'm no flow engineer, but I think that maybe a similar amount of air flows over the panel as under it (when driving) so it's not just constantly trying to peel up (?). That's not to say they shouldn't be fastened down of course! Just that they don't seem to "tear off" in the way you might intuitively think that they would.

I have seen or heard of very few failures, and that includes the AM Solar feet which have a relatively small area for VHB. (I still wanted a bit more surface area for the VHB because, why not, there doesn't seem to be a downside to me.)

Speaking of "air dams," I'm about to try the latest of my "stop the wind noise!" attempts on the original Chinook Fantastic Vent (which makes the noise due to being located too close to the front edge). "Footage at ten" (or whenever I get around to making the test).

Back to panels: Compared to many installations, 1-1/4" is actually a fairly close gap. I want my panels to go as close to the roof as possible without crossing some invisible "line" that makes them get hotter than necessary, and to me 1-1/4" seemed to be about that number. Maybe 1-1/2". My buddy's panels on AM Solar feet were higher, although I forget the exact number. Maybe 1-3/4" or 2"? My original Siemens panel was practically touching the roof, but then nothing about that installation was ideal (however I'm not dissing it as it was done at a different time, had a different purpose, etc.).

One note is that the tier we're speaking of actually slopes slightly outboard. So if the brackets are drilled identically the panels will slope slightly outboard. I suppose that would be good for drainage, but it looked slightly odd to me, so I may drill my brackets to make the panels more level (will have to see how I feel at the time).

BG

PS: I just checked AM Solar's brackets and they have either 3 or 5 adjustment holes depending on the size you get. The holes are at 1-1/8”, 1-1/2”, 1-7/8, 2-1/4” or 2-5/8” . The smaller bracket just uses the first three hole heights. There is also a higher one that goes from the mid-2's to the upper 3's. Their brackets use a "clip" that mounts to the side of the solar panel, so the panel would be slightly lower than the equivalent bracket mounting to a downward projecting ear.

I think their brackets are probably the nicest of the "store bought" ones, and I even bought a set, but I ultimately decided to go another way.

[HoosierB]

WoW! The AM Solar website has a lot of great info and videos. The SP100 panel w/rocker mounts looks like a winner... even the panel size would work (41 x 20.9").

[Blue~Go]

From everything I can tell, the SP 100 is the new version of the Grape GS-100. I bought a pair of the latter panels from them a couple of years ago before they went to the black version, and then became unobtainable. Now they are back. They are very small in size for the 100 watts (reason is because they are efficient enough that they get 100 watts out of 32 cells vs. the usual 36). Spec-wise, these look nearly identical to the newer Renogy Eclipse. However, the Eclipse has a glossy black frame, whereas the SP-100 has the more typical anodized natural aluminum color frame. I prefer the silver color, but that's subjective.

The mounts are nicely made, but they don't come cheap. I don't mind spending for good stuff, but since they didn't quite work out for my project, I ended up making my own (because it didn't make sense to me to buy expensive mounts, then change them all around anyway).

They used to also have a "matching" (dimension wise) 135 watt panel. It was ~21" x ~58". When I thought I needed all the solar I could pile on (before actually trying it). I had bought a pair of the 135's and a pair of the 100's. But putting one of each on each side tier, I would have had 470 watts. I later found out that I didn't need that much on the roof -- andI don't want to give up a pair of ground panels because I like parking in the shade and/or the ground panels are very easy to tilt/orient in the winter, when I want to milk the little there is, but I don't have to try to orient the Chinook a specific way (thus I can orient it better to the other site features).

So now I have the ground panels (some lightweight Grape 100-watters they used to sell), and have used the rigid 100 watt panels on another project. That leaves the pair of 135's for the roof, although in some ways I'm tempted to just get a pair of the SP 100's just because 100 is so universal. OTOH, I can fit the 135's and another 70 watts won't be a problem. It's really one of those "we'll see what happens when I actually get to doing it." It's easy to put off when I have other interesting things to do and the ground panels give me more power than I need (but roof panels will still be super handy for certain situations).

This is what my mounts look like at the moment. The little "drop ear" piece will be fastened to the bottom horizontal rim of the solar panel with two 1/4" fasteners. Then a 1/4" Rivnut (nutsert) will go into the larger center hole. The bigger right angled pieces will go on the roof with VHB, with the part that contacts the roof tucking under the panel. Then when I decide just where I want it, I'll drill a hole in the upright of the larger piece. A shoulder bolt with then go through that hole and into the Rivnut.

Still to be proven in actual use, of course.

[kdarling]

I see what you're saying. But, the length, gauge, and connectors for the wires are unlikely to be correct for the Chinook project ...

The gauges are correct for the wire length they send, for those panels. So making them shorter would be fine. Now sure, if they're are not long enough, that changes everything.

Or maybe I'm just a curmudgeon

By this age, we're all curmudgeons

• replace/controller charger with something like a Sunforce 60023 30amp (temporary and inexpensive, but more efficient than existing with no modifications for fit)

IMO, that one would be just throwing good money after bad. It's still PWM, so you could be throwing away 20+ watts of your 100 watt panel.

If you're planning on expanding later, might as well get an MPPT controller now. Preferably one with programmable charge points and optional temp sensor (like the one in the kit, or one that Blue recommends).

That's why I was saying that Renogy kit isn't so bad for someone who wants a decent plug and play setup.

Cheers, Kev

[HoosierB]

Per Mr. Rooney, I looked up HANDY BOB'S blog.... a very, very interesting read.

https://handybobsolar.wordpress.com/rv- ... ck-answer/

[Blue~Go]

www.jackdanmayer.com also has some good info. I liked his way of addressing things.

The basics are gaining the sun energy (panels), not losing it on the way to the controller or from the controller to the batteries (wire size), getting the most out of what comes in (controller), being safe (fuses). And also keeping an eye on things (monitor(s)).

The monitors are especially helpful in the beginning. Once things are rolling along you typically don't have to watch it like a hawk (but by then it's fun to watch as you silently gain power!). After a short while it's more like your gas gauge on a trip. When you first get the vehicle, you don't know its habits, and you watch it constantly. After a while, you get to know it, and then you only glance occasionally, and even when you are not glancing, you still have a pretty accurate idea of where things stand. It's just kind of automatically in the back of your mind.