Solar panel installation - Oceanis 31 - advice

May 12, 2021
16
Beneteau Océanis 31 Christchurch
I need to install at least one solar panel to trickle charge 2 domestic batteries - I’d appreciate any advice on the best route for the cabling. I have the choice of installing a semi-flexible panel on the deck under the boom and in front of the sprayhood or to install on the sprayhood itself (my preference being the former). The two domestic batteries are located inside the engine cowling. I’ve unscrewed a couple of ceiling panels but this raised as many questions as it answered. Any advice much appreciated.
 
Nov 21, 2007
631
Beneteau Oceanis 34 Kingston, WA
I installed solar panels on my Oceanis 34 last year. At the same time, I was able to install larger batteries for the two domestics in the same location. I installed two 110 watt semi-flexible panels mounted on the top of our bimini. After completing both installations, our time away from shore power has increased from a couple of days, at most, to nearly unlimited during the summer (we are located at reasonably similar latitudes). I would recommend prioritizing the size of the panel over the preferred location. Install the largest panel that will fit in either location, and let the size dictate where it will be installed. I ended up running the cable through a water-tight deck gland, installed near the lift-up seat on the port side. I had to drill a large hole and run the cable forward to the batteries, but it has made our time away from the dock MUCH more relaxing!
Good luck!
 
May 12, 2021
16
Beneteau Océanis 31 Christchurch
Thank you for your advice. I guess at the back of my mind was the thought that cable routing might help me make a quick choice but I think you are right - I need to make power requirement a priority and think again. Our previous boat had one panel and a lantern wind generator and whilst these were fine for topping up they didn’t really support running the fridge. Having to use the heating on occasion at the moment in the Oceanis makes this more of a challenge. We don’t have a bimini fitted at present but it’s something I should maybe have prioritised. Thanks again.
 
May 17, 2004
5,032
Beneteau Oceanis 37 Havre de Grace
@LRsunnyB I’d be careful about putting a panel under the boom. Solar panels are very affected by shading; more so than you’d expect just based on the percentage of the whole panel that’s shaded.

@SoSound how did you have the panels attached to your Bimini? I gather that you’re happy with the quality of the panels and their durability so far? I remember the thread last year talking about the wiring and now we’re considering making the same upgrade to our 37.
 
Nov 21, 2007
631
Beneteau Oceanis 34 Kingston, WA
The panels are still only attached using a couple of loops of small line and bungees which criss cross the canvas on the bimini. I'm still planning on installing velcro around at least three sides of each panel. I found that charging dropped way off when the angle of the sun got low last fall, I think that I would like to be able to release one end of each panel so that they are not as curved, and end up being flatter relative to the sun.
Solar panels - 1.jpeg
 

Alfa

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Mar 19, 2015
38
Beneteau 31 North Vancouver
I need to install at least one solar panel to trickle charge 2 domestic batteries - I’d appreciate any advice on the best route for the cabling. I have the choice of installing a semi-flexible panel on the deck under the boom and in front of the sprayhood or to install on the sprayhood itself (my preference being the former). The two domestic batteries are located inside the engine cowling. I’ve unscrewed a couple of ceiling panels but this raised as many questions as it answered. Any advice much appreciated.
 

Alfa

.
Mar 19, 2015
38
Beneteau 31 North Vancouver
I installed on my B31 two semi-flexible 100W panels on rigid frames above bimini. Cables run along back Bimini tubing and enter the hull inside Life Raft compartment.
The frame for each panel is made from discarded fibreglass hockey sticks, providing light and rigid base for each panel. Each panel is attached to 1” OD SST tubes above Bimini fabric. In this design, I have room for future installation of additional two 100W panels (400W total). In winter, boat is covered, therefore Bimini and panels are removed.
 

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Jan 7, 2014
396
Beneteau 45F5 51551 Port Jefferson
I installed my flexible panel on the deck under the boom. My boat is on a mooring, the sun, the boom the boat all need to be aligned to cast shade on the panel. It rarely happens and it won't happen all day every day so I tolerate it. For me that is the best location since I don't always sail with the dodger and bimini up. The panel is fastened with exterior hook/loop type velcro so I can remove it and because I don't like putting holes in my boat. I remove it in the fall and screw it to a piece of plywood and place it outside my winter cover to keep the batteries topped up in the winter.
I was able to run the cables under the traveler and hidden along the edge of the companionway hatch, then down a flat white pvc conduit into the engine compartment and down to the controller and battery bank for a neat install.
 
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Dec 28, 2015
28
Beneteau Oceanis 31 Le Crouesty Brittany
I installed 2 x 110W solar panels on my O31. They are mounted on orientable supports fastened on a monotube stabilized to the bimini structure.
The monotubing arch is hinged to the rear pulpit.
The overall installation looks quite light which is fine on a small boat.
 

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May 12, 2021
16
Beneteau Océanis 31 Christchurch
I installed on my B31 two semi-flexible 100W panels on rigid frames above bimini. Cables run along back Bimini tubing and enter the hull inside Life Raft compartment.
The frame for each panel is made from discarded fibreglass hockey sticks, providing light and rigid base for each panel. Each panel is attached to 1” OD SST tubes above Bimini fabric. In this design, I have room for future installation of additional two 100W panels (400W total). In winter, boat is covered, therefore Bimini and panels are removed.
This looks like a good solution - being expandable and removable is also a good idea. Extremely useful to see your photos too. I don’t have a bimini fitted at present but it’s on my wish list - I’ll have a look for a neighbouring boat with one next time I’m in a marina and explore further. Many thanks for your response.
 
May 12, 2021
16
Beneteau Océanis 31 Christchurch
I installed 2 x 110W solar panels on my O31. They are mounted on orientable supports fastened on a monotube stabilized to the bimini structure.
The monotubing arch is hinged to the rear pulpit.
The overall installation looks quite light which is fine on a small boat.
This looks like another good solution - many thanks for your advice and photos too.
 
May 12, 2021
16
Beneteau Océanis 31 Christchurch
I installed my flexible panel on the deck under the boom. My boat is on a mooring, the sun, the boom the boat all need to be aligned to cast shade on the panel. It rarely happens and it won't happen all day every day so I tolerate it. For me that is the best location since I don't always sail with the dodger and bimini up. The panel is fastened with exterior hook/loop type velcro so I can remove it and because I don't like putting holes in my boat. I remove it in the fall and screw it to a piece of plywood and place it outside my winter cover to keep the batteries topped up in the winter.
I was able to run the cables under the traveler and hidden along the edge of the companionway hatch, then down a flat white pvc conduit into the engine compartment and down to the controller and battery bank for a neat install.
Many thanks for your reply. Under the boom seemed like an appealing & straightforward solution to me apart from routing the wiring, so I appreciate your advice here. I also dread making any holes (deck or down below) so thought of fixing with adhesive or heavy duty velcro. My only reservation has been that the area available to me under the boom would only allow for an 80w panel at most, which I fear may be a bit limited where I live on the south coast of England. I might have to add a small wind generator at a later date to complement - wind we have no shortage of most of the time.
 
Jan 10, 2018
260
Beneteau 331 Halifax
If you are trickle charging a 20 watt panel is sufficient. I got the panel, flipped it over and screwed two pieces of wood crosswise underneath after I had bolted these to the wood. This attaches the panel to the rail. The wires went down the SS tubing at the stern and the wire went through the back of the deck with what is called a "cable and deck connector". This has worked very well for me.
 

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May 12, 2021
16
Beneteau Océanis 31 Christchurch
If you are trickle charging a 20 watt panel is sufficient. I got the panel, flipped it over and screwed two pieces of wood crosswise underneath after I had bolted these to the wood. This attaches the panel to the rail. The wires went down the SS tubing at the stern and the wire went through the back of the deck with what is called a "cable and deck connector". This has worked very well for me.
Thanks for your reply - I’ve not seen these rail clamps before, although I did notice some boats in the marina in winter with panels attached to the dodgers; the clamps look useful and presumably they can be set at an angle too. Agree that trickle charging wouldn’t need much but I’ll need to go for higher wattage as I need more autonomy particularly in the use of the fridge (I currently switch it on when motoring but then off when at anchor and the voltage drops too low; with a couple of frozen bottles of water to begin with the temperature remains correct for a couple of days). I loathe running the engine just for charging and it’s surprising how much the water pump needs when it kicks in; fortunately heating is not needed at the moment.
 
Jan 10, 2018
260
Beneteau 331 Halifax
Thank you for your reply. Yes, go with bigger wattage for what you are doing.
Those rail clamps are very strong. There is rubber where they meet the rail. You can loosen the wingnut and adjust the tilt. They would be capable of supporting a good sized panel, and you could always fashion a strut going back to a tube.
One fellow I know had a flexible panel stitched to his bimini and it keeps his fridge going very well.
 
Apr 26, 2019
10
Beneteau Oceanis 31 Toronto Islands
To add to other posts... I have two 100 panels mounted on the bimini. Trial and error process to find the right method to mount to the bimini canvas but at the end of the day have used magnets. Six small strong circular magnets (Amazon), held to the underside of each panel with small nuts/bolt and six on the underside of the bimini. Makes it easy to remove when not cruising. I also placed some short lengths of small diameter pvc tubing between the panels and the canvas to allow some air circulation and to stiffen the flexible panel. I've had bad luck with panel cells cracking but this was mostly likely due to my first mounting attempt where the panel was positioned over the frame of the bimini. Since re-orienting across the bimini no trouble and the magnets seem to hold quite well. Wires from the panels are cable tied to the port back stay and pass under the life raft bench and into cabin. Wires are then passed under the boards supporting mattress (cable tied to existing wiring harness) and up to the engine compartment. Controller and breakers mounted above the engine access panel and wires passed through engine compartment to house batteries in engine compartment. As far as I can tell the fridge draws about 2-3 amps (but only draw approx 50% of the time) and the panels provide sufficient energy to keep the batteries topped up.
 
May 12, 2021
16
Beneteau Océanis 31 Christchurch
Thank you for your advice - it sounds like a useful and flexible solution. I don’t have a bimini at present but will bear this in mind if/when I do. Useful to know how you routed the cabling on the same boat as ours, even if it seems obvious once you’ve done it - the prospect of making bad wiring route choices is daunting. At the moment I’m leaning towards installing a small panel on the deck below the boom in front of the sprayhood (as it looks like the moulded panel unscrews) and a lantern windgen on a pole on the port stern - your wiring suggestion should work well for this. Many thanks and bon vent.