How much solar do you have?

[B27]

Don't forget that peole managed to enjoy cruising under sail before solar power.

It's nice to vastly reduce the occasions when you run the engine because your batteries are low, but if you get a few cloudy days in a row and end up motoring around the bay to charge the batteries, it's not the end of the world.
Diminishing returns become a thing, 50W of solar powers my fridge in nice weather, 100W will do it in mediocre weather, to achieve zero dependence on engine might need 300W of solar, which is probably pointless as we will probably want to motor somewhere anyway.

 

[noelex]

That's true up to a point. Liveaboards tend to go to places with abundant sun (sweeping generalisation...). For those in Northern latitudes solar alone is less likely to provide year round reliability, particularly if heating is wanted.

That said, this is an interesting thread and is making me think before I consider replacing any bits of my system.

My wife and I enjoy cruising both tropical and cold locations. Each cruising ground has its appeal.

Heating the boat with electricity derived from solar power is not practical. Here diesel heating is the best option if shore power is unavailable.

This energy option can complement solar power. Tasks such as heating water for showers and cooking can be done using diesel or diesel/propane in colder climates and electrically using solar energy in warmer climates. The energy needed to refrigerate and freeze food is also reduced in cold climates so the energy balance can still be made to work without a generator or shore power even in areas of relatively poor solar insolation.

 

[noelex]

My latest boat - 38ft - you'd think that it would be easy to mount more than enough solar to not need shore power ... but the boat is not destined for a cruiser only life ... its a Cruiser Racer ... so last thing I want is a bimini / arch etc. ....

You should always set up your boat to suit your particular needs.

I don’t advocate every boat should be generating all their electrical energy from solar, but it is an option that should be considered rather than dismissed as unachievable or impractical.

 

[Refueler]

You should always set up your boat to suit your particular needs.

[/QUOTE]

Absolutely - that applies to so many things not only solar on boats !

I don’t advocate every boat should be generating all their electrical energy from solar, but it is an option that should be considered rather than dismissed as unachievable or impractical.

If you read my post as dismissal of installing - then you misread my whole point.

 

[Roberto]

luxuries such as electric cooking

Vade retro Satana, rather seems a curse to me, anywhere

 

[LiftyK]

120W portable, southern England

 

[Kelpie]

I'm surprised that, after four pages, I've still got the largest amount of solar. Not bad for an old 39ft boat.

Here in the Caribbean, 1kw+ of solar is by no means unusual. The bigger cats simply sling four big panels above their davits to give ~1600w. Although every so often you do come across a boat running a generator. Disturbing the peace, producing pollution, and wasting money. But some people are strange.

 

[geem]

I'm surprised that, after four pages, I've still got the largest amount of solar. Not bad for an old 39ft boat.

Here in the Caribbean, 1kw+ of solar is by no means unusual. The bigger cats simply sling four big panels above their davits to give ~1600w. Although every so often you do come across a boat running a generator. Disturbing the peace, producing pollution, and wasting money. But some people are strange.

The worst ones are those petrol suitcase generators they stick on the sugar scoop so they can't here but everybody else can

 

[Neeves]

I'm surprised that, after four pages, I've still got the largest amount of solar. Not bad for an old 39ft boat.

Here in the Caribbean, 1kw+ of solar is by no means unusual. The bigger cats simply sling four big panels above their davits to give ~1600w. Although every so often you do come across a boat running a generator. Disturbing the peace, producing pollution, and wasting money. But some people are strange.

Don't be quite so harsh.

The gen set came with the yacht, they could scrap it and use the money they have been saving for a....?? (trip to Labrador/Alaska/Patagonia).

These are 3 yachts plying Patagonian waters. The cat has a decent array on the cockpit roof (and considering they are normally based in Tahiti its almost minimalist). The 2 monos have insignificant solar and they were not alone with their small solar panels (but all, including the cat, had copious ground tackle). All the yachts (excepting the cat) had a decent chimney (the cat may have had a chimney, hidden).

I don't know how many amps each yacht needed - but solar was not a top priority (and I suspect either the engine or a gen set filled the gap






Different priorities, horses for courses.

There is a large part of the world in northern high latitudes and a significant part of the world in southern high altitudes. Many of the respondents to this thread are based in low latitudes where sunlight is guaranteed. Without the guarantees you are camping or need another source of power (other than solar) and this includes place close to 'home', Scotland, Tasmania,

Don't knock the gen set, yet.

And as I ponder further - everyone is quoting, I suspect, ideal conditions and not mentioning how the solar panels cope when actually sailing. It depends on how you live 'at sea' (not much video ) but lots of Nav equipment and an AP to soak up any extra amps. Personally when at sea hydro generation beats solar hands down (and justifies use of wind gen (as it converts to hydro). Eclectic...??

Jonathan

 

[john_morris_uk]

I'm surprised that, after four pages, I've still got the largest amount of solar. Not bad for an old 39ft boat.

Here in the Caribbean, 1kw+ of solar is by no means unusual. The bigger cats simply sling four big panels above their davits to give ~1600w. Although every so often you do come across a boat running a generator. Disturbing the peace, producing pollution, and wasting money. But some people are strange.

Running our generator (when we occasionally need to ) is considerably less polluting than using the main engine. As we’ve got a water separating exhaust and silencer I’d challenge you to hear it from more than a few meters away. It’s extremely quiet.

 

[Kelpie]

There is a large part of the world in northern high latitudes and a significant part of the world in southern high altitudes. Many of the respondents to this thread are based in low latitudes where sunlight is guaranteed. Without the guarantees you are camping or need another source of power (other than solar) and this includes place close to 'home', Scotland, Tasmania,

Don't knock the gen set, yet.

Oh absolutely. I'm originally from pretty far north myself (c.58⁰) so I know a bit about trying to rely on solar power. Mind you, I only cruised in the summer back home so it was surprisingly easy to get by on solar when it's only dark for about 4hrs each night.
Out of season high latitude cruising will clearly need to burn some fossil fuels.

What I see around here, thankfully quite rarely, is boats that are clearly based in these low latitudes yet have not bothered to invest in any meaningful amount of solar, and instead run a suitcase genny on deck for a couple of hours a day.

When you look at the cost of a generator, and the fuel and servicing, then compare it to solar, it just doesn't make any sense that people still do this. I suspect in many cases it's long term cruisers who set up their boat a decade ago when the economics were different.

And as I ponder further - everyone is quoting, I suspect, ideal conditions and not mentioning how the solar panels cope when actually sailing. It depends on how you live 'at sea' (not much video ) but lots of Nav equipment and an AP to soak up any extra amps. Personally when at sea hydro generation beats solar hands down (and justifies use of wind gen (as it converts to hydro). Eclectic...??

Jonathan

I was told by many people that we would struggle for power on our transat, that we would need to run the engine, etc etc. I picked up a secondhand Aquair in anticipation of this.
In practice, yes the increased demand of nav equipment, coupled with shading from the sails, definitely makes it much harder to run off solar alone when on passage. I stow the two 100w deck mounted panels when doing anything more than a day sail, which brings the main array down to 730w.
We switched back to gas cooking for the duration of the crossing, and used the wind vane most of the time, and would certainly have run out of power otherwise. In 18 days from Mindelo to Guadeloupe, we relied entirely on solar. At one point we dipped to 14% SOC and I was contemplating setting up the Aquair. We never ran the engine to charge, which is just as well because we can't. We run a 50l fridge and a 45l freezer, both of which stayed on throughout the crossing.

 

[geem]

Don't be quite so harsh.

The gen set came with the yacht, they could scrap it and use the money they have been saving for a....?? (trip to Labrador/Alaska/Patagonia).

These are 3 yachts plying Patagonian waters. The cat has a decent array on the cockpit roof (and considering they are normally based in Tahiti its almost minimalist). The 2 monos have insignificant solar and they were not alone with their small solar panels (but all, including the cat, had copious ground tackle). All the yachts (excepting the cat) had a decent chimney (the cat may have had a chimney, hidden).

I don't know how many amps each yacht needed - but solar was not a top priority (and I suspect either the engine or a gen set filled the gap

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Different priorities, horses for courses.

There is a large part of the world in northern high latitudes and a significant part of the world in southern high altitudes. Many of the respondents to this thread are based in low latitudes where sunlight is guaranteed. Without the guarantees you are camping or need another source of power (other than solar) and this includes place close to 'home', Scotland, Tasmania,

Don't knock the gen set, yet.

And as I ponder further - everyone is quoting, I suspect, ideal conditions and not mentioning how the solar panels cope when actually sailing. It depends on how you live 'at sea' (not much video ) but lots of Nav equipment and an AP to soak up any extra amps. Personally when at sea hydro generation beats solar hands down (and justifies use of wind gen (as it converts to hydro). Eclectic...??

Jonathan

Our hydro generator in perfect conditions (average boat speed over 7kts) will produce 240Ah per day at 12v. That is something like 3kw of power. By comparison, at anchor, our solar has produced 4.4kw. Average is about 3.5kw here in the Caribbean. Having both is great for us, as often when sailing, a lot of the solar is shadowed by sails. Just as an aside, having panels on the guardwires gives us a lot more output when sailing as we can tilt them. Especially helpful when the boat is heeling away from the sun.
The other thing to consider, is that solar is cheap. Hydrogenerators are not. You can have a lot of solar for the cost of hydro. A big lithium battery easily sees us through the night. It will be interesting to see how we fair on the West to East crossing of the pond next year with lithium.

 

[Trident]

I'm surprised that, after four pages, I've still got the largest amount of solar. Not bad for an old 39ft boat.

Here in the Caribbean, 1kw+ of solar is by no means unusual. The bigger cats simply sling four big panels above their davits to give ~1600w. Although every so often you do come across a boat running a generator. Disturbing the peace, producing pollution, and wasting money. But some people are strange.

We have just under 2000w in three banks through three MPPT to a 700ah LifePo4 bank - runs full size fridge and a freezer, all cooking and everything else. I have two 60 amp DCDC with 2 x 125amp alternators - which I've had to use twice now this summer with the terrible weather and a Victron AC-DC charger which I tested once and used twice in 3 years . We ran over three years during Covid etc living aboard with total requirements met by solar from April to October in the UK - only in real winter did we need shore power.

 

[West Coast]

I have 200W on a 44' AWB, comprising 2 panels of 100W each mounted on the guard rails on hinge brackets. New to me this year, but have made a huge difference in keeping our lead acid house batteries at around 90 - 95% up when away from marinas and anchored for a few days. Main elecy use when anchored is fridge, blow air heating, lighting.

I am based in Scotland, and pondered between a wind genny, briefcase type genny and solar. This from Nigel Calder persuaded me - see at 55min40s His conclusion that in Scotland his solar outperformed his wind genny by 2:1 is most interesting

, .

 

[geem]

I have 200W on a 44' AWB, comprising 2 panels of 100W each mounted on the guard rails on hinge brackets. New to me this year, but have made a huge difference in keeping our lead acid house batteries at around 90 - 95% up when away from marinas and anchored for a few days. Main elecy use when anchored is fridge, blow air heating, lighting.

I am based in Scotland, and pondered between a wind genny, briefcase type genny and solar. This from Nigel Calder persuaded me - see at 55min40s His conclusion that in Scotland his solar outperformed his wind genny by 2:1 is most interesting

, .

If you spent as much on solar as you would on a wind turbine, the solar will massively out perform it. The only problem is finding enough space for it all.
Our wind turbines contribution to our boat is tiny compared to the solar

 

[West Coast]

If you spent as much on solar as you would on a wind turbine, the solar will massively out perform it. The only problem is finding enough space for it all.
Our wind turbines contribution to our boat is tiny compared to the solar

Indeed, this is especially the case in sunnier climates, but particularly interesting to note Nigel Calders findings in Scotland following the comment by Neeves earlier in post 69.

 

[noelex]

Solar in high latitudes during the cruising season can work well.

The long daylight hours are a great help.

 

[Neeves]

One reason solar is rated more highly than wind is because the cost of solar has dropped and become more efficient and wind has remained the same. Go back 20 years and solar was expensive. And for the China bashers - one reason solar is cheap is because its now almost exclusively made in China, 20 years ago the best solar was from Germany. Now, without searching for the Best Buy, I can buy a folding 250 watt solar panel with regulator for stg80, including tax, and a flexible 200 watt panel with a 10m extension cord for slightly less, stg75. I'm sure if I shopped around I could reduce these prices (our tax is 10%)

You only need 3 days of bad weather and wind makes an interesting contribution, particularly when at sea. The advantage of wind is - it takes up no space but if you choose judiciously it will convert to a hydro gen. Our Aero4aquagen makes 10 amps at 10 knots in hydro mode, and at night - we would not be without it. We only wish we had bought the bigger model and 2 of them (the unit is now 25 years old).

We are on our third generation of, flexible, solar panels - yes the wind/hydro gen is, was, much more expensive but do the costs over 25 years and you might come to a different conclusion. That 250 watt folding panel is cheap as chips but it only works in daylight hours (and not all of them) and will it last 25 years and counting?

Again - horses for courses.

Jonathan

 

[noelex]

One of the the problems with wind generation is that it hard to position the generator where it will not shade the solar panels.

 

[Neeves]

One of the the problems with wind generation is that it hard to position the generator where it will not shade the solar panels.

Lateral thinking.

I'd be more worried about the sails, boom, mast shading the solar panels - about which you can do nothing.

Careful planning means you can ensure the wind gen does not shade any panels, ketches are ideal (masthead or spreaders). It is very easy to have a pylon constructed that is offset/cranked so the wind gen is well outboard (and it is then also clear of the sails) - lots of options. All you need is a good imagination.

Our original pylon was on the port quarter and could be swung well outboard (and swung in board if we were rafted up or in a marina). We moved the location to the centre of the bridge deck transom but the pylon was cranked so that the wind gen was located well aft of 'anything' and well over and aft of the davits and caught the wind off the main as long as we were not running.

This is our wind gen on the transom, the pylon is secured to the aft of the bridge deck transom with large 'U' bolts and big backing plates. The wind gen does not produce any shadow over the solars, but the boom does . Since then we added a single 200 watt panel to the roof, in the obvious 'empty' space, and a roving 250 watt panel. I cannot recommend flexible panels - but they offer the sensible way to use the saloon roof and still allow work on the main. Solid panels are better, which could be mounted on the davits - except we hold the kayaks on the davits


Jonathan