Last winter I have mounted two 235W Sanyo solar panels, one which can be rotated on the davits and one on the bimini. It has worked wonderfully last summer during our return trip Netherlands-Portugal. With sun on both panels I have seen 25 ampere produced.
I got a lot of inspiration from Cotemar's description, but of course I wanted to (hopefully) improve on his system...
I have described the system and the davits construction in posts 47, 50 and 52 of this thread.
Now I want to inform you how I mounted the second panel on the bimini.
I mounted it more forward than Cotemar did. Reasons:
- Less chance of the bimini flapping against the frame (because the rear corner of the solar panel is closer to the mounting)
- Wires could pass through the roof neatly
- Weight more central
- Fewer holes required in the bimini.
But admittedly 4 holes have to be made in the roof: 2 for the threads and 2 for the electrical
wires, with cable glands.
Front mounting: I made 2 blocks from massive PVC using saw and file. This took some patience, the upper and lower surfaces of the blocks are not parallel. I could have used tropical wood but don't like to paint
See attached drawing. I tapped thread 8 mm in this block, using studs to mount the PVC block with sealant
to the roof. A nut is on the inside of the ship. The solar panels are connected to the PVC block with 2 bolts and nyloc nuts in recessed holes. Note that with this construction (and the nylocs) it is difficult for thieves to take the solar panel off without going inside to remove the 8 mm nut.
On the rear side I have used two Gemini
split type side mounts just as Cotemar did, see post number 20 and previous of this thread. In the bimini I made 2 holes strengthened with stainless steel
rings with 17 mm internal diameter.
The 18 mm tops of the Gemini
side mounts had to made oval with a file to allow them to go through this 17 mm hole. (next size was 25 mm, that's too big).
Around the stems of the Gemini side mounts I mounted short pieces of hose, cut open on the side. I used two inside each other of different diameter. The inner one is a tight fit around the stems, the other one a tight fit around the inner. They are fixed with tie-wraps. The length is chosen so that they press the eyes in the bimini on the Gemini side mounts.
They prevent wear by flapping of the bimini against the sides and corners of the solar panel, and also prevent rain water
getting through the holes in the bimini.
Under the solar panel the electrical cables
pass inside the cabin
using cable glands.
To remove the bimini for the winter: for this the rear mounting has to be detached, the bimini has to be lifted over the Gemini side mounts. Despite the rigid front PVC mounting, there is enough torsion in the solar panels to lift
the solar panel 1-2 cm to slip the bimini over the Gemini side mounts. First you need to detach the port hexagonal-headed bolt fixing the solar panel to the Gemini side mount. Then you slip the bimini over the Gemini side mount. Then re-mount this bolt. Then repeat the process for the other bolt.
The electrical wiring
can nicely be brought to the port engine
room through an existing duct and the navigation
table furniture. It is only visible just under the roof.
If somebody wants a description of this let me know.
Of course this solar panel is especially useful for sailing west in the northern hemiphese, especially with southerly winds. But combined with the davits panel we get enough electricity, even on gloomy days.