Solar Panel mount options?

Ahoy,

I have been reading all of the recent solar related posts and I would like some opinions on an aspect of the installations that seems to get little discussion.

I am planning to install 2 Panasonic 325W solar panels on the roof of my pilot house. I am investigating mount options and am coming up a bit frustrated.

These are fixed frame glass panels about 62"x44". There is enough room for them, but I'm not sure what would be the most correct, and aesthetic, method to attach them to the boat structure.

I have done this before on my sailboat, but that was a much different animal. There is no crossover, other than the proper electrical installation. Using screwed in L or Z brackets seems crude and a source for future leakage.

Ideally, I would want a somewhat invisible method that would still be strong enough for marine conditions.

Any suggestions?

Mutt,

This is what I did, pretty much invisible. Screwed into the roof and bedded with 4200. There is about a 1/8" gap under the edge of the panels at the roof curve.

Bob

You want at least a small gap underneath the panels for air circulation to keep them cool. Heat causes the panel's output to drop.

So, on a buddy's boat with a pair of 250 watt panels we used sections of angle aluminum that we bolted to the edge of the panel. Then we used a tube of West Systems thickened epoxy to glue the aluminum angle to the roof top. No nead for screws.

For your bigger panels, I would use one bracket on each corner and two more in the middle of the long dimension.

If you are concerned about epoxy being too permanent, then use 4200. It will hold them on very well without screws.

David

I used these on a 320 watt panel. Three year now and no problems, zero hole in boat, except for wires.
https://rvsolarstore.com/index.php?route=product/product&product_id=112

Panels I fitted 6 years back have right angle metal angle screwed to them, the other angle flat is screwed to teak block mounts 1" high, the blocks are attached to the deck using Sikaflex(? = 5200). Not only do you not penetrate the deck, the Sika takes up any unevenness, avoiding the risk of stressing the panel frame and glass by screwing to the deck.

I mounted 4 panels, 2 onto each of my hardtops. I secured the center sections of two panels directly to the the hardtop and the outer edges were lifted about 1 1/2" using PVC boards that I cut to that width.

The purpose of raising the outer edges was to keep the panels flat and avoid the hardtop's curvature. I used silicon caulking compound for the adhesive. MY panels are SECURE with silicon. For those who want to avoid silicon, there are numerous other adhesive such as 5200.

Personally, I don't want any unneeded holes anywhere especially for tiny clips.

See http://www.trawlerforum.com/forums/s32/need-advice-canvas-contract-35378.html post #12

Somewhere there is another post of mine showing the actual panel installation.

I wanted no fasteners in the roof so used hollow plastic garden sleepers cut into sections about 100mm wide.
These were about 40mm thick allowing good airspace.
Being hollow I could bolt the panel to it and then simply sanded the plastic where it sat on the roof and sanded the roof where the plastic foot sat and sikaflexed them down.

9 big 250w panels have seen several 50 knot and a 80knot storm with no issue.

Wow, some great ideas.

I've never heard of sleepers before.

I particularly like the self sticking, adjustable height mounts (post #4).

Thanks to all.

Bill

I'm really delighted to hear about you guys having real-world success with adhesive-only mounts!

As mentioned in another thread: “I bought $20 of angle aluminum and pre-drilled then cut off 1.5" pieces with a chop saw. I bolted 2 pieces together in a "U" with washers and nylock nuts, bolted these to the 4 corners and then glued to the pilothouse roof with 4200. Prior to positioning I put blocks of wood in place so the panel supports would rest 1/8" above the roof so all the 4200 wouldn't squish out. They are solid 2 years later. I figure if I have to rebed every 5 or so years, that's fine.”

A fellow KK42 used an industrial double sided tape which worked well for him.

This is my setup.

Would rigid solar panels, raised for air circulation, survive a four foot snowfall? We get 3 foot snowfalls at least once a winter and had 7.5 feet of snow in two days a few winters ago.

The 5km road to our marina is usually closed during these heavy snow events, so the panels would have to fend for themselves until I could get down there to shovel off Badger.

Yes NP at all

Bob Cofer said:

Mutt,

This is what I did, pretty much invisible. Screwed into the roof and bedded with 4200. There is about a 1/8" gap under the edge of the panels at the roof curve.

Bob

Click to expand...

Why not use 5200 without the screws? If you ever need to remove it, it's easier to grind 5200 than to patch screw holes...and no risk of creating a leak source.

Rebel112r said:

I used these on a 320 watt panel. Three year now and no problems, zero hole in boat, except for wires.
https://rvsolarstore.com/index.php?route=product/product&product_id=112

Click to expand...

That's what I'm talking about!! Another nice solution product from the RV industry!

MurrayM said:

Would rigid solar panels, raised for air circulation, survive a four foot snowfall? We get 3 foot snowfalls at least once a winter and had 7.5 feet of snow in two days a few winters ago.

The 5km road to our marina is usually closed during these heavy snow events, so the panels would have to fend for themselves until I could get down there to shovel off Badger.

Click to expand...

If I lived where there was that much snow, I'd be more concerned about the ice loads. I'd cover my panels for the winter to protect them from the snow/ice load. If practical, a sloped cover to allow for load shedding would be helpful.

Has anyone done any sort of hinged mount so you can tip the panels up for access and cleaning under them? I've seen on very nice solution with fabricated stainless hinges, but it was many times more expensive than the panels. I'm trying to come up with something more practical.

I just have to undo two bolts and losses the other two and mine should tilt up, depending on the amount of slack available with the wires.

FlyWright said:

Why not use 5200 without the screws? If you ever need to remove it, it's easier to grind 5200 than to patch screw holes...and no risk of creating a leak source.

Click to expand...

I had a real life experience removing 4 each 145W panels last summer to replace them with 4 each 295W panels. Removing ANYTHING secured with 5200 is no walk in the park. I DO NOT RECOMMEND 5200 FOR PANELS unless they never need to be removed.

foggysail said:

i had a real life experience removing 4 each 145w panels last summer to replace them with 4 each 295w panels. Removing anything secured with 5200 is no walk in the park. I do not recommend 5200 for panels unless they never need to be removed.

Click to expand...

ok....4200uv?

MurrayM said:

Would rigid solar panels, raised for air circulation, survive a four foot snowfall? We get 3 foot snowfalls at least once a winter and had 7.5 feet of snow in two days a few winters ago.

The 5km road to our marina is usually closed during these heavy snow events, so the panels would have to fend for themselves until I could get down there to shovel off Badger.

Click to expand...

My panels are secured completely along the panels long edges. I doubt 4' of snow would hurt them but here in Massachusetts I have my boat shrink wrapped.

FlyWright - screws are just my personal choice. Too much time in the big waters, “if it ain’t bolted it ain’t secure”.

"I DO NOT RECOMMEND 5200 FOR PANELS unless they never need to be removed."

Usually the Hull to Deck joint is seldom removed , everything else is PM.