What size solar panel/panels for a single handed sailing.

[Geoff A]

I use a Ray marine ST 2000 tiller pilot, I tend to use it rather than being stuck to the tiller, I balance the sails as best as I can to keep power usage down. I have a 27ft long keeled boat. The instruments I use are depth sounder, mast head wind with cockpit display, VHF radio, the appropriate lights at night, I have a Samsung 8inch tablet from London Chart plotters. Steve of LCP has been very helpful and given me an approx amp hour usage over a 24hr period at 120w used. I hope to be doing a couple of longish over night trips in the spring. I can run the engine to top up the batteries when running at night or when the weather is overcast. The boat has two 100ah batteries. Any helpful advice welcomed.

 

[Sea Change]

Just fit the biggest panel(s) you can, in a convenient place. Hatch garage is the obvious location, one each side of the cockpit hanging off the guard wires works well too.

The technology is so cheap these days that there's no point trying to minimise the size and cost of the installation.

Rigid panels tend to be much better value than flexible ones, they last longer and need no further support structure.

A few years ago I spent nearly £100 on a 10w panel. Today you can buy a rooftop type panel for about £50, and it will produce over 400w. Smaller panels suitable for a 27ft boat will cost more per watt but you get the idea.

 

[Sandy]

Hello @Geoff A have you worked out your power usage in 24 hours?

I sail a 10.10 metre boat, 33 feet in old money, and have 2 * 100 watt panels and that usually keeps up with my usage.

House bank is 390 Ah giving 195 usable Ah + engine battery.

 

[PaulRainbow]

Just fit the biggest panel(s) you can, in a convenient place. Hatch garage is the obvious location, one each side of the cockpit hanging off the guard wires works well too.

The technology is so cheap these days that there's no point trying to minimise the size and cost of the installation.

Rigid panels tend to be much better value than flexible ones, they last longer and need no further support structure.

A few years ago I spent nearly £100 on a 10w panel. Today you can buy a rooftop type panel for about £50, and it will produce over 400w. Smaller panels suitable for a 27ft boat will cost more per watt but you get the idea.

400w panels for £50 ?

 

[Buck Turgidson]

I sailed 18 days nonstop from UK to Valencia using a tiller pilot / sheet to tiller / Hand steering on my twister.
Similar instruments to you Nav lights are LED. 110w of solar with occasional engine charging on the overcast days. 200ah AGM.
You don't need much. Night time with Tiller pilot off my load was 1.25A. With tiller pilot on it depends on the sea state but worst average load was 4A.

2x 55W flexi panels on the spray hood in series to a victron 75/15 MPPT. still going strong.

 

[vyv_cox]

In springtime in UK your panels will not develop anywhere near their rated power. In May, June and July in Greece my 125 watts will run my fridge indefinitely but outside those months, especially if it clouds over, rarely, we need to run the engine.

 

[doug748]

I use a Ray marine ST 2000 tiller pilot, I tend to use it rather than being stuck to the tiller, I balance the sails as best as I can to keep power usage down. I have a 27ft long keeled boat. The instruments I use are depth sounder, mast head wind with cockpit display, VHF radio, the appropriate lights at night, I have a Samsung 8inch tablet from London Chart plotters. Steve of LCP has been very helpful and given me an approx amp hour usage over a 24hr period at 120w used. I hope to be doing a couple of longish over night trips in the spring. I can run the engine to top up the batteries when running at night or when the weather is overcast. The boat has two 100ah batteries. Any helpful advice welcomed.

I have a similar set up and requirements. I agree with post two, anything at all would help and you really need nothing at all, as long as you set off with reasonably charged batteries. If you have a rough 24 hours you may want to engine charge esp if the batteries are a bit long in the tooth.
I have a 10 watt panel which works for me, it's unobtrusive and sits on the pushpit.

.

 

[MontyMariner]

As in #2, fit as much as you can. You don't mention a fridge, so that's quite a saving.
Put in a twin output regulator to dual charge house and engine banks, as when the engine bank is full, all the power is directed to the house bank, so nothing is lost.
I don't use a dedicated engine bank, I have two banks of 2x120ah batteries, but I can reconfigure to 3 house for long Biscay passages, and 2x80 watt solar which seems to cope with my extravagant needs - fridge (but not run cold enough to make ice or stop cubes melting) and a TV used at anchor plus all the normal nautical equipment, including AH5000+, CP, AIS transceiver and occasionally the Radar.

 

[PaulRainbow]

As in #2, fit as much as you can. You don't mention a fridge, so that's quite a saving.
Put in a twin output regulator to dual charge house and engine banks, as when the engine bank is full, all the power is directed to the house bank, so nothing is lost.
I don't use a dedicated engine bank, I have two banks of 2x120ah batteries, but I can reconfigure to 3 house for long Biscay passages, and 2x80 watt solar which seems to cope with my extravagant needs - fridge (but not run cold enough to make ice or stop cubes melting) and a TV used at anchor plus all the normal nautical equipment, including AH5000+, CP, AIS transceiver and occasionally the Radar.

A bank of 3 will cycle less and charge faster.

 

[Sea Change]

400w panels for £50 ?

Solar PV Panels | City Plumbing

that was just the first place I thought of, you can likely get better deals elsewhere, especially in bulk.

 

[PaulRainbow]

Solar PV Panels | City Plumbing

that was just the first place I thought of, you can likely get better deals elsewhere, especially in bulk.

If they get much cheaper they'll be giving them away !!

 

[Sea Change]

If they get much cheaper they'll be giving them away !!

People are already using them to make fences...
Global glut turns solar panels into garden fencing option

 

[PaulRainbow]

People are already using them to make fences...
Global glut turns solar panels into garden fencing option

Blimey, at those prices they would make a cheap shed too.

 

[William_H]

The solar PV panels in the link are made for domestic roof top PV systems. Typically a house may have 15 of them. Physically large size limited by what a man can mange on a roof top to fit,. typically 40 or more volts open circuit voltage, made mostly in China in their millions. That is why they are cheap. But yes very good.
For a boat you need the space for the large panel and of course an MPPT regulator to charge a 12v or 24v battery. Smaller more manageable sized 20v max panels for leisure become relatively much more expensive due to low demand. ol'will

 

[oldmanofthehills]

4ft by 2ft (1.2m by 0.6m) flexi panels suitable for coachroof mounting come in at about £100 inc regulator. Mine is declared 200W but I think thats china puff and its nearer 100W in practice. Still 2 of them should give a reasonable output and as each has own regulator they can be combined even if differently aligned such that one might be in part shade sometime. Modern ones dont need direct sunlight though it helps

 

[vyv_cox]

4ft by 2ft (1.2m by 0.6m) flexi panels suitable for coachroof mounting come in at about £100 inc regulator. Mine is declared 200W but I think thats china puff and its nearer 100W in practice. Still 2 of them should give a reasonable output and as each has own regulator they can be combined even if differently aligned such that one might be in part shade sometime. Modern ones dont need direct sunlight though it helps

I bought a rigid one that size last week. It was from Eco-worthy, claimed to give 190 watts thanks to a transparent construction that allows light to the back. Apparently some customers wire them together as a fence. It cost me €93 delivered (in France). I installed it on the motorhome yesterday, where it seems to be working well.

 

[oldmanofthehills]

I might stick a couple on campervan next to roofbox. Would help as usually off grid or at festival and aux bat depletes after a couple of day. Stangely smooth curved boat coach roof easier the crinkling van top

 

[Stemar]

If you're putting panels on the hatch garage - that's where mine are, use two panels in parallel, as the area will be shaded by the boom. One panel will have its output drastically reduced by this, but with a pair, you'll still get full output from the unshaded one.

 

[dansaskip]

I have a 80w panel mounted on a gantry - so it doesn't suffer much from shading. I was going to fit 2 60w panels for the reasons Stemar states about shading but at the time I could only get the 80w one. I use a Blue Solar MPPT controller but also have a VCR for balance charging on my battery bank of 2. Alp LED lights throughout.
Found this set up keeps batteries charged up on long trips without resort to running the engine - even crossing oceans. But then again I don't rely on a tiler pilot but use a windvane.

 

[garymalmgren]

RE;I use a Ray marine ST 2000 tiller pilot, I tend to use it rather than being stuck to the tiller, I balance the sails as best as I can to keep power usage down.

Tillerpilots are great when motoring , but to save on tillerpilot power usage you can you can use a wind vane (expensive) or sheet to tiller steering.
It takes a bit of fiddling , but proven.