What size Solar panels do you have?

Sy-Revolution

Sy-Revolution

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Hi folks,
I'm about to get a radar arch made up, well more of a solar panel/ariel arch actually, and need to have an idea of what size panels it will be designed to take. In terms of width I've got about 2500mm to play with.
We're going to be heading 'south' to warmer climes so the fridge will be running more than it is here, I'll have a watermaker, TV, Laptop and the usual boaty stuff.
I have a Honda suitcase genny (just 1000w) but don't want to use it as a regular thing and don't want to run my engine daily either (carbon foot print etc), however, we're not unused to roughing it............
There's my self, my partner and our 6 year old son, we'll be long term livaboards (inshaAllah).

So what have you got in terms of wattage and is it sufficient?


Cheers,

Crispin.
 
You could have a 100w or more.I have an 85w to run the fridge two 50w panels to run everything else and a 20w to keep the batteries up if were away for a day or two.

Solar panels are needed can be different for each boat depending on your power needs and space.We use 2 50w as one provides our daily needs in the med and 2 for the colder less sunny north or two if need be.

The 85w is to run the fridge and adds to the 50w.at night we turn the fridge off.

If you have to much solar power it will ruin your batteries or be bad for the regulater which i hate and dont use as they cut out at 13.8v best is to manage your power yourself with care and thought
 
Put up as much as you can fit BUT be careful with the choice and the other gadgets you put on the arch which may cast a shadow over the panels. There are many panels with good output for area but many of them will reduce their output by 90% with only part of one cell shadowed by an extending pole from the arch. The trouble is solar panel manufacturers seldom mention the shadowing issue because they are made for "open sky" installation not marine sky-clutter. Ask around about what panels are least affected by shadow. PBO did some tests in their Oct05 issue. Whilst not exhaustive they did highlight the shadowing problem by showing that a number of panels reduced their output 50% or more with the shadow of one halyard!

I have 2x54W Sunware panels of the "shadow resistant" version and 2 x64W Uni-Solar. The Sunware are made as 2x27W sections side-by-side on the same panel. I have them mounted on the top of the dodger. This means even if one half of one of the panels is shadowed by the boom, I still get 1.5 panel output. The 2 UniSolar panels do not provide a high output for their area but they have an internal diode between each cell to allow current to flow if one or more cells are shadowed. So even though they do not have a high Watts/sqm rating they do provide consistent output even if shadowed and are good with cloud cover too so I believe they are better overall.

I am not trying to sell you on these brands, just highlighting the issues.

Solar power does require a significant initial investment but if you are heading towards the equator you will appreciate the quiet low maintenance supply of electrons that they can provide.
Ray
 
3 x 68watt panels plus rutland 913 seem to keep up with requirements at anchor. More than this needed for sustained passage making with autopilot and nav lights - towed generator or run engine. LED cabin lights make a big difference to consumption.
 
We too were looking at making an arch to accommodate a long list of things including solar panels that could be angled to the sun for maximum output. In the end it seemed too much trouble and expense so we forgot the arch and went for the flexible thin type that you can walk on. Fitted 2 x 68 watts on the foredeck and they blend in with the tinted hatches very well. Found some waterproof deck fittings at Maplins where the cables come out horizontally which makes a great installation. They are simply Sikaflexed to the deck. We could still add more panels in other locations if we need more power, but these cop well with shadows and when used with our towing genny we arrive with more AHs than we left with, and that’s with two chartplotters an autopilot and a fridge/freezer.

The flexible panels aren’t as efficient as the rigid ones but the convenience and the appearance seem worth it. The boat also has a built-in 5W panel that is just for the starter motor.
 
Thanks for the replies so far, I forgot to mention that I also have a Rutland 913.
So the consensus so far is that it's better to have a number of smaller panels rather than one biggy and around 200 watts........

Any brand names/suppliers that are prefered?


Crispin.
 
We have just received two panels, 85 watt and 40 watt, made by Kyocera, from www.midsummerenergy.co.uk They were the cheapest we found. The panels look pretty good to me, rigid ones that will fit well on a simple arch astern.

We have had 70 watts up until now but this really wasn't enough.

We have also had a petrol generator for one season but the noise it made was deafening and wholly anti-social, so it has been returned home.
 
I have 1 x 180 watts, but would purchase more smaller ones next time due to the shadowing issue.

I know someone who has 4 x 125 watts + a wind generator.
 
2 x 130W Kyocera panels feeding a 500Ah house bank. Seemed to work fine for a family of 4 with fridge etc and didn't need to run engine for charging (at least in summer). No wind genny or petrol genny. Have never regretted spending the money on the panels.
 
2 X 125 Watt rigid Solara
3 X 68 Watt semi-rigid.
House battery bank of 440 A/H
Ampair 100 towed genny/wind genny
Got my fingers crossed for the tropics, indications are it might be enough. I have all LED lighting. The capital outlay was frightening and I could have got a 3.5 KVA diesel generator for slightly less, but last time I had a diesel generator it kept going wrong!
 
We have a watermaker (Spectra) and make all of our own water once we have left the marina in the spring. That's going to be a big item for you. What type, what does it draw, what is the output quantity and how much water do you want to be able to make?

Are you going to be substantially passage-making, at anchor, or a marina boat when not at sea?

What parts of the world are you planning to sail through?

What was the rationale for the 1000W genny - usually they only have a 700W output continuous so you might have a problem with some chargers? Have you checked?

How big are your batteries?

Do you plan to run any other big-ticket items? Laptops all day, etc.?
 
Hi Lemain,
I wondered how long it would be before you surfaced /forums/images/graemlins/smile.gif

I plan to make a watermaker so I'm not sure of the power consumption yet. We hope to be independent of marinas as much as possible and plans are Med for now but further south in years to come.
The Genny is one that we own already and use on our market stall so there's the rationale.........

I'll have around a 500ah battery bank. We have a C120, the laptop is for 'recreational' use not navigation. We have an auto pilot but use this mainly when motoring/short periods. Hydrovane to be fitted when the money tree bears more fruit!

Crispin
 
Surfaced? That won't happen for a long time /forums/images/graemlins/wink.gif

All these things are possible but we need a bit more detail. Solar is good when the sun is shining as long as you have enough capacity and if you had to make an either/or choice for the Med it would be solar, not wind.

My solar panels are huge - 185W x 2 and I could use double that. But I also have a 6kVA generator.
 
I have 2 x 80 watt BP solar panels together with a Rutland 913 fitted on a bespoke made arch at the stern of the boat (a moody 425)

The solar panels are 500mm x 1005mm and take up the whole of the beam of the boat at that point. They are mounted on a frame that can be tilted to face the sun and this really makes a huge difference.

The 913 is mounted to the same arch in the centre and offset aftwards to minimise shadows.

The arch itself is fitted direct to the aluminium toe rail at each side of the boat to minimise hole drilling to the gel coat and provide a firm strong platform.

As the arch is raked it also provides ideal davits for the dinghy.

If you want further info let me know.
 
I also find the Unisolar 64w panels good. I have two of these and they do work very well in poor light conditions. I also have two 40 watt panels that I made portable. They have sail hanks bolted to the ali frame so I can clip them on to the guardrail. They then have a notched dowel support that is adjustable for angle off the bottom guardrail. They can be adjusted a couple of times a day and provide great output because of this. In good sun light my 4 panels (208w) put up to 13 amps in the batteries. In addition we have a Duogen. This set up is suffiecent to run the fridge freezer, watermaker, lights, radar, auto pilot and anything else we can think off without ever needing to run the engine for charging.
 
>What do you people use to provide hot water? That's the thing which always forces us to run the engine.


Solar showers; worked very well in the Med but I guess it depends where you are. That and a kettle for hot water to wash up. Not the poshest solution but worked well in the med where most of the time you are happy with a cold shower anyway.

Another solution would be an Eberspacher diesel water heater.

Anthony
 
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