Right then, how shall I mount my solar panel?

A 12 watt solar panel will not keep you cool box going!

The maximum current you can expect from the solar panel will be around 3/4 amp and that will be for a limited number of hours only.

A Peltier element cool box will draw about 4 amps contiuously.
 
Iain

what size batteries are they please, and in what condition ?

The wind genny and pvpanel you have are little more than top up devices for the out-of-use periods. As VicS says, they will not provide the beef needed to run a cool box over the weekend, but.... if you have say two fully (fully) charged 110 AHr batteries you might be able to run the box for quite a lot of the weekend, without knackering them both. Though if one is the engine start battery...:(


Can I suggest you stick some of the maths together ? Battery capacity, type, and configuration (domestic, engine, 12B switch, etc), and then a realistic pattern of power usage for lights, coolbox, instruments). Then a hard look at the efficiencies and likely charging patterns of the Forgen and the pv panel.

It's looking very much in the balance as to whether your total outputs match the inputs, and you don't want to over-discharge the batteries.
 
and you don't want to over-discharge the batteries.
Click to expand...

Not more than 50%, unless they are genuine deep cycle batteries

It means that if you power you cool box from the battery and recharge that once per 24 hours you need a battery with a capacity of around 200Ah + the means to recharge it from 50% in a reasonable period of time
 
I was looking ar the Forgen wind generators mentioned in this thread.

Who would pay over £400 for a wind generator that only produces a maximum of 18W?

surely if you are serious about a wind generator, then not a lot more gets you a Rutland generator with something more like 100W or more of output.
 
maplin panel

i bought one of these panels last week, thought i would clear a few things up...

They seemed to have a 12w and a 15w panel on offer when i went in to Maplins so i opted for the 15w one at £49.99

The weight quoted at 4kg is because it comes with a very solid metal frame to hold it up at an angle on a permanent install, that is a seperate bit that needs assembling , i put it striaght in the bin. Without the frame, it is pretty light.

As for output, I was just chucking it up on deck, laying flat when moored up and it managed (much to my surprise) 1.0 amps at 12.7v at the weekend at about 1pm in full sun, generally it was managing a useful 0.3-0.7 amps in fairly cloudy weather and was still showing 0.1amps till pretty much sunset.
 
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consider how the boat lies with the tide, hopefully the river you are on is E/W . . .

you have got to get the panel to face into the direction of the sun for it to produce a good output

i have my panels near vertical on the side of the cabin, gives a better return than straight up, unless your boat is in africa, not, by the looks of your attire ;)
 
I am a bit of a minimum boater. I have mounted my panel on the pushpit overhanging the transom. Ive only got 20ft to play with so anything outboard is free space. See attached pics
 
I have been playing with a pair of 40W rigid monocrystalline panels recently (£160 for the pair on EBAY). (ie 80W nominal in total).

Under ideal conditions (clear, midday, panels oriented optimally) each panel produces around 2.5A into the battery.

In reality if the boat is moving around, the best compromise (given my mounting options) seems to be one panel each side at about 30deg to horizontal, which gives an average charge around 2A in total. (ie you actually achieve around 25W from a nominal 80W of panels). Still very useful.

My experience with this type of panel is that even the SLIGHTEST shadow reduces the output dramatically. (no experience of the amorphous sort).

Vic
 
I like your idea for the backstay mount. Gets it out of the way and no shadows if the sun is coming from the rear of the boat. I would do the same except our backstay is adjustable. The rigid panels are badly affected by even a small amount of shadow so deck mounting means they never deliver much charge. I plan to mount ours using the bimini struts on mounts that allow it to be either over the bimini and shaded by the backstay but less obtrusive or behind the backstay and unshaded.
 
Right then, the backstay idea is dead. It would have worked just fine, apart from the fact that this weekend I was making a mental not how many times I would have hit my head on it, and the answer is "lots"! I also quite like standing right at the back of the cockpit between the split parts of the backstay, which would not have worked!

I am going to install it though, just as a cheap and cheerful way of keeping things topped up between trips, so I will be making a "hoop" for the pushpit to mount it (and a fee other bits) on.

Can you bend 316 grade stainless pipe with a plumber's pipe bender? And does anyone know of any ready made s/s clamps that I can join it to the pushpit with?
 
We keep ours here when not sailing:
5743605417_2ef99ceda8_z.jpg
 
I'm not in favour of these temporary installations. Best to find a permanent place for it attached to the boat not the rigging even if the aspect is not optimum. Many solar panels are OK to tread on (although I try to avoid it).
BTW I notice that Plastimo are now selling PV panels at quite a good price.
 
Iain C said:
Can you bend 316 grade stainless pipe with a plumber's pipe bender? And does anyone know of any ready made s/s clamps that I can join it to the pushpit with?
Click to expand...

You can bend 316 tube with a good professional/hired pipe bender but not with a DIY one. Many liveaboards just make up arches or supports using standard elbows and Tees. I use Baseline for them, they seem to be competitive on price and very good to deal with.

I have found plastic blocks on sale for the mounting job but they were horrendously expensive, something like £14 each, four to a panel. I designed a simple system in stainless and had a local shop weld them up, the cost for the five I needed was very reasonable.

Mounted mine like this, using the radar pole as a support.
Panelsandradar.jpg
 
Vyv

Thanks for the pointer to baseline, I'll be able to make something up from there. My stern rail is very crowded with outboard, various bits of MOB kit, antennae etc so it will be useful to be able to space it all out a bit and mount the panel somewhere out the way.
 
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