John, I know you were concerned about thread-napping, but I felt that your topic was deserving of its own thread. Thus moved here. Good topic, sure to get lots of answers and hopefully some photos.

I put ours on the davits, it just seemed to make sense, big area of space there pointing straight up. Doesn't interfere with using the ladder or stern platform even though it's the biggest panel I could buy (230 watts - 64" X 39"). Shades most of the dinghy keeping rain water out and prolonging life of cheezy PVC rubber parts. Not totally happy with the mount I have yet, am looking into a mount that will let me tilt the panel plus it is sitting a touch low, it gets shaded by the bimini earlier in the evening than I expected it would.

I'm not a fan of arches on sailboats for mostly aesthetic reasons but also because I think that's a lot of weight to be adding way up high and it's bad for the CG but certainly that'd be a good choice as well. I ruled out mounts on the lifelines because I think the panel would get damaged sooner or later out there. Deck just didn't seem practical for a big panel. Stick didn't seem to be able to carry near the size of panel one needs to actually make useable power.

After much thought and planning, I am installing two panels on top of the Bimini as I do not have Davits. The weight still worries me, but there seems to be little alternative.
John Meyer
Hilbre 2135 San Pedro, CA

Top of the bimini was my 2nd choice. Duane Ising has a really neat setup with panels on both davit mounts and bimini mounts. We're adding wind gen so hopefully a single 230 panel is all we'll need. If we do need a 2nd panel it will go above the bimini. Not much other choice really.

John,

I have been swamped and did not post pics of my installation yet. I will try to do that tonight.

Our PO had bimini framing installed to hold two 120W panels near the aft end of the bimini. When hurricane Charley Cat 4 came right on top of us in 2004, the bimini, dodger, and all sails were off the boat, but the solar panels were left on as they are pretty permanent. They panels were unscathed, which was pure luck with all the flying debris, BUT the important part was that the framing was not distorted or bent despite all that wind loading.

We later added more framing forward of those panels and mounted a third 120W panel athwartships just behind the boom end. I then added davits and later a fourth (and final) 120W panel on top of them.

It works for us.

Here's some pics of our installation. It is very busy at the back of the boat now with the davits, solar, BBQ and tank. Davits came from Stainless Outfitters in Barrie, ON, they make a nice unit 1 1/4" tubing and all the mounts are made custom for individual boats but included in the price. Also got the extra bracing for the stern rail from them which makes a nice place to carry two extra jerry jugs of fuel and also makes good handrails when coming up the swim ladder. The panel can be shifted fore and aft easily on the davits so it doesn't interfere with using the transom platform and ladder. Davits have two braces across them so a very good surface to mount panels on.

Next up (hopefully next week) the wind gen, having Stainless Outfitters make a custom mount for it that includes a built in crane for the dinghy outboard so it is taking some time to get done.

I well know what you mean by "busy at the stern." If you are a cruiser, that's pretty much what it has to be.

Bud:
Thanks, these were really helpful pictures as I had also been wondering where to store/mount an auxilliary LPG tank for long cruises and Bingo, there is my answer, a great location.
John Meyer
Hilbre 2135, San Pedro, CA

Glad to be of unintended help. That's a 20 lb aluminum tank. We had been looking for another 10 lb for a spare and at the Toronto boat show last Jan. a dealer had 20 lb tanks for 79 bucks, 10 lb tanks were $239. Kind of a no brainer, except it won't fit the propane locker. So I built a mount that will carry either tank, we run off the 20 lb and keep the 10 lb full as a spare in the propane locker. Had the 10 lb upgraded with the new style valve and got it re-certified.

That is the working tank, all the original propane plumbing was moved to the stern, the pass through nut for the hoses now comes out the top of the transom. There is a 'T' on it so it runs the stove/oven and the BBQ. Ran all summer on that 20 lb tank, every weekend since May 24th and 3 weeks of holidays.

Can't solar panels be mounted on a platform a few inchs high beteen the mast and the cabin hatch? This would have a lower center of gravity and the weight would not be on the stern which slows the boat down. I realize the panels would be partially shaded by the boom, but even if we don't race we still appreciate a better preforming sailboat.

Could do but I don't think a panel the size of ours would fit there what with all the blocks and lines coming from the mast. It would have to be fairly high to clear all that stuff. I guess it depends on your priorities.

We don't notice any difference in the way the boat sails since we put all that stuff on the stern. In fact I can't even see any difference in the waterline. Though the pictures don't show it, that 1" white line between the bottom paint and the boot top is still above water. It is for now anyway, I'm going to paint it over next spring, hate the way it goes all brown, rather not have it not there than have it look yucky.

The shading problem will be bigger than you expect since it will occur at all times, not just at beginning or end of day. In mast furling would reduce it but with a sail or sail cover above it, there will be a lot of shade. That much shade is going to significantly reduce the panel output, possibly by as much as 50% depending on the size of the panels. For us, the loss of panel output is more of an issue than the effect on the performance. Maybe it's because we are used to 28 foot speeds and this boat is just so much faster than the 28 was. But for someone who is more tuned to the boat performance than I am it may be an acceptable trade off.

We get 14 amps max out of that panel and it's the biggest I could find and using an MPPT controller that is a very recent design. That's under ideal conditions for maybe 4 or 5 hours a day. Less before and after that, a lot less when its cloudy. Cut that in half and its a big hit.

I have to agree with Bud. If you care enough about being energy independent for cruising away from shore power, then small sailing performance decreases are insignificant.

To me, with the potentially substantial investment in the panels, controller, wiring, and mounting hardware, I want to optimize their performance with the best location. If you rarely spend much time at anchor, avoid the weight and expense of a separate passive charging system and just use your engine's alternator and some fuel.

I honestly believe one of the best locations to mount a solar panel would be on top of the bimini. In doing so, it would always be out of the way and would have the best chance of catching as much of the sun as possible. I have been contemplating the idea of adding another solar panel to my boat. I presently have a very small one that trickle charges a battery that is dedicated solely to the backup bilge and a radio in the cockpit and it works like a champ.

If a panel is mounted above the bimini you would have to ensure that you could take the canvas off (like we did here in North Carolina, in anticipation of Hurricane Earl) who BTW, didn't really make landfall and couse problems for us.

I mounted twin 120 watt power panels on top of the bimini. They are connected to the batteries via a solar controller and a battery combiner. They pump out a fair bit of power (I have not measured it yet).

Photo attached.

OK, my pics, finally. Sorry for the delay. The shot from the mashead shows all four panels. The side shot was before I added the last panel.