Solar ....again!!

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daveg45

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Hi All


I am trying to fit some panels to a Dufour 425 and a frame at the stern isnt a practical or cost effective solution. One option is to fit 3 * 36 watt flexible panels to the deck infront of the sprayhood. My concerns are shading from the boom and attaching something which could develop faults to the deck of the boat. Also seems a lot of work/cost for a small input. (sailing area Galicia then the med)

I wonder if anyone has used this location with success or any other ideas around.
 
Strange, I can offer a comment to both ideas here as I have one 30 Watt panel (all I need) which I move around, ie: not fixed. It sits happily just forward of the canopy, luckily in a recess on the cabin top so I don't secure it down other than a light lashing. When under way it is usually in the sun when the boom is to one side, but the problems begin when the boom is amidships and I then have to move the panel into the sun.

I've got a couple of home made brackets which allow it to hang outboard on the sunny side of the after rails which works well at anchor or alongside. Even as I type this there is a German boat opposite me with some big panels permanently rigged as Happydaze points out, swung out at angles on his rail. Looks a bit damage vulnerable to be though, like a Viking Longship with shields over the side..:D :D
 
When anchored, wrap the bendy solar panel round the boom. Neatly out of the way and in the sun. Underway, hang it off the guardwires.

Cheaper and esthetically pleasing when compared to the scaffolding one sees.
 
michael_w said:
When anchored, wrap the bendy solar panel round the boom. Neatly out of the way and in the sun. Underway, hang it off the guardwires.

Cheaper and esthetically pleasing when compared to the scaffolding one sees.
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Nice as a fashion accessory but for the panel to work well, most of the panel must face the sun or within 30 degrees of it, so a bendy panel wrapped around the boom will only produce low voltage all day and will not do it's job.
 
daveg45 said:
Yes I thought of that one. I wasn't sure how successful it would be.
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It would be very successful indeed, all you need think about is the actual wiring and make sure or get advice on robust but very flexible (pun intended) wiring which will withstand constant movement. ;)

The idea that solar panels have to be facing the sun and angled at exactly 30° etc, etc is a little bit of a myth. :confused:

The will work quite well but will not give 'full' current output. That does not mean the output fall away dramatically but it will be less but not seriously less. It might be 20% down on current output but at least it will work and you can always get a further panel or two to make up the deficit. There isn't a yacht afloat which can guarantee to point their solar panels to the sun constantly it will always be a compromise and a trade off. :rolleyes: :)
 
In practice, the boom option is very effective. Obviously, if the sun is shining from ahead/astern it pays to move your free range panel accordingly. As you don't need an expensive frame you can afford to get more panels or a wind/petrol generator too.:cool:
 
daveg45 said:
Hi All


I am trying to fit some panels to a Dufour 425 and a frame at the stern isnt a practical or cost effective solution. One option is to fit 3 * 36 watt flexible panels to the deck infront of the sprayhood. My concerns are shading from the boom and attaching something which could develop faults to the deck of the boat. Also seems a lot of work/cost for a small input. (sailing area Galicia then the med)

I wonder if anyone has used this location with success or any other ideas around.
Click to expand...

I have a 60w panel just forward of the sprayhood on a Dufour 40, not sure exactly what it is delivering as the boat is fairly new to us.

The flexible panel is screwed to the deck but I would not envisage major problems or damage if it were removed
 
Happydaze said:
You could put 1 or 2 panels on the guard wires towards the aft quarters that will swing out and be propped in position when at anchor or in light winds.
Click to expand...

I considered this option on our Dufour 385, but for Med use where we normally go stern-to, the risk of damage seemed too great. Have seen two damaged solar panel mounted in this position and have seen a couple of near misses. We ended up going with a stern arch and 2 x 100W panels. Not cheap, but once fitted you can just forget about them.
 
We have gone through many of the options. Our original panel was 38 Watts, on deck aft of the mast. It was in shade for a large proportion of the day and never performed very well. We still have it for keeping batteries topped up in winter, boom removed, through a controller.

Next we added a 32 Watt flexible. It worked well but was a PITA, we always seemed to be moving it around. With an awning it was difficult to attach on the boom and when sailing it needed six lines to hold it down on deck. On the foredeck at anchor it was in the way quite often, often needed moving and still saw some shadows.

Finally I made up an arch fairly cheaply using standard fittings and mounted 40 and 85 Watt panels on it. It works well, is rarely in shadow and runs the fridge 24/7. I made it to tilt for maximum sun exposure but soon realised this to be quite unnecessary.

Over the course of the past six years of full-time summer cruising I have destroyed a total of five stanchions, not all of them my fault. Every incident would have wrecked a panel hanging on the guard wires.
 
Have you thought about mounting on a single pole? mounted at a rear quarter with 2 support angle posts.
Either 1 or 2 panels mounted rigid or tiltable, cheaper than an arch and easier to install.

At present the most efficient solar panels are only able to convert 15% of available light to energy so anything you can do to maximize output without having to fit many panels is a good way to save money.
 
I am 100% with vyv_cox on this. If solar power really matters to you, especially if it really matters to you while under way, I would strongly recommend going for a permanent installation with a good clear view of the sky. That usually means a frame off the back. These temporary 'floating' arrangement are ok for supplementing power at anchor, but in my experience they are a useless pain in the neck under way.
 
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A pal of mine here has a Jeanneau SO 40, and she recently acquired a large (it is 5' x 3' in plan view!) 200 watt solar panel to avoid dependence on the engine for battery charging (keeping the beers cold in the fridge was a priority.....).

The boat was previously fitted with a large conventional canvas bimini on S/S hoops over the cockpit, but we decided that this solar panel was simply too big and heavy to simply lash down on top of this bimini - also, the clearance between the end of the boom and the split backstays would have been very tight.

So we decided to have a variation on a theme of a 'T-Top' built by a local fibreglass boatbuilder and aluminium fabricator - a couple of photos are attached below.
The solar panel really chucks out the amps - however the electric fridge has now packed up and probably needs to be replaced....... :(

Bimini3.jpg


Bimini1.jpg
 
Re:Solar....again!!

Not sure if this helpful, but maybe it will give you some ideas.

http://www.sailnet.com/forums/gear-maintenance-articles/19863-choosing-installing-solar-panels.html

http://www.marine-solar-panels.com/marine-solar-panel-mounts

This uses self sealing screws and is completely flexible to fit the any deck shape and shade tolerant - will still produce a charge when shaded by sail. All amorphous panels are shade tolerant. Full Disclosure: This is from my website but I don't make money from it. I just couldn't find a resource out there where people told you what panels worked well for marine application.

http://www.marine-solar-panels.com/...panels/uni-solar-68-watt-flexible-solar-panel

Also helpful:
http://www.custommarineproducts.com/solar-panel-mount.html

These things are really lightweight and have grommet holes. The first picture is wrong. They don't have any metal. They're thin and small and light weight so I think you can temporarily mount then fairly easily with and rig it up with a quick connect so you can install and uninstall it fairly easily.

http://www.marine-solar-panels.com/.../sunwize-solcharger-small-marine-solar-panels
 
We've got 2x68W semi-flexible panels screwed down to our foredeck (Najad 391). When sailing they are often shaded by the jib, but at anchor in the Med last year they just about kept pace with normal daily consumption. I've never seen them produce anything like their theoretical 11A (no surprise), but I've often seen 6-7A in S Spain, mid-summer.
 
Ours are getting elderly (7 years now) but we have two flexibles that live on the sprayhood underway and get moved around at anchor, icnluding sitting on top of our shade cover. They crossed Biscay and have done a lot of med miels sitting on the sprayhood so they're safe, though they are shaded part of the time.

We also have a big rigid panel on a mount of a steel pole across tehd avits. This is ok and chucks in amps, but is a PITA as it means we can never go in stern to. This spring we have seen two other yachts with pushpit mounted, adjustable panels and we are now reviewing this option as both of them have been very comfortable with the arrangements. We have resisted them up to now for the damage concerns (as vyv mentions). One point is that both those yachts, as ours, have 1" diameter steel rail pushpits on which to mount the panels, rather than wires run between stanchions.

We could always do with more power - especially right now here in Portoferraio where it's been overcast/raining a lot of the last few days as well as pretty still which means the wind genny hasn't had much chance either. But hey! we're at anchor and we're managing. (I'm typing this after all!)
 
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