Wind Vs. Solar - Best Options

[44'cruisingcat]

These days solar is much better value. You're looking at around $1200-1500 and up for a wind generator installed. And it'll produce maybe 400 watts in a gale.


That money would buy you a much larger solar array. As long as you have the real estate to mount it.

[Kenomac]

Originally Posted by Dockhead

My own experience with wind, with a highly rated wind generator, is that it produces zero useful power, while cluttering the stern of the boat and producing noise. Even though I live in a very windy place. Others I know here have had the same experience.

My own experience with solar is that it produces wonderfully useful power at all latitudes. It might work even better at higher latitudes because of longer daylight hours and cooler temperatures.

Solar is a nearly ideal power source. Except for one little thing -- there is almost no way to put a reasonable amount of solar on a cruising boat without turning it into a windage-ridden junk pile. A barn door mounted on a pile of stainless off your stern? If you don't really like to sail then maybe that's not a problem -- it was absolutely superb on my father's boat -- but for me that's just not acceptable.

Therefore, forced to choose between wind and solar, I chose -- a diesel generator.

The only problem with only using a diesel generator is the inability to top off the batteries on a daily basis if one lives on the hook 99% of the time. Our battery bank has turned to junk in less than four years, now only able to charge up to 370 amp hours when the capacity should be 800 amp hours. We like to sail, BUT... I'm not going to spend 2000€ every four years to replace the house bank and continue to listen to the generator run three hours per day, 180 days per year.

That's why we are now in the design process for a 500w solar array to hang off the back. Lightweight, Solbian high efficiency. Not the humongous ones designed for rooftops.

[Dockhead]

Originally Posted by Kenomac

The only problem with only using a diesel generator is the inability to top off the batteries on a daily basis if one lives on the hook 99% of the time. Our battery bank has turned to junk in less than four years, now only able to charge up to 370 amp hours when the capacity should be 800 amp hours. We like to sail, BUT... I'm not going to spend 2000€ every four years to replace the house bank and continue to listen to the generator run three hours per day, 180 days per year.

That's why we are now in the design process for a 500w solar array to hang off the back. Lightweight, Solbian high efficiency. Not the humongous ones designed for rooftops.

Will you be able to take it off and stow it while sailing? If I could find something like that, I'd be solar in a heartbeat.

Sent from my D6633 using Cruisers Sailing Forum mobile app

[Snowpetrel]

Originally Posted by Jim Cate

Hell, BEn, even here in the Pittwater (~33 deg S) now that winter is here, we find that we need to supplement the solar with some diesel burning. The combination of low sun angle and short days is a killer, even in mid latitudes imo.

Note that we have an Air-X wind gen too, but these last few weeks have been mostly low wind in this area.

Jim

Hi Jim, thats interesting, I must admit when I lived aboard winter was always a dark time for me, with my two little 40 watt panels being adjusted carefully to maximize the sunlight collected. And my use being carefully rationed.

I can't remember if your panels are adjustable or not? Certainly down here the difference in power gained by tilting them was significant, especially in the morning and evening. Athough it meant regular adjustment as the wind and sun shifted, and it probably isn't practical with a large array.

I had minimal needs (no fridge, only occasional laptop and TV use) which 80 w of carefully adjusted solar just kept up with over winter.

I had a wind gen on my first boat, but it was very erratic in port. It worked well at sea because I always seemed to be going to windward! It was the old style air marine with no high wind shutdown. So it would keep cranking in the power even in gale force winds. The new air x type I have since used has the high wind shutdown mode which always seems to cut in around 30 knots? And to often at sea it seemed to shut itself down in stronger winds when it would be real nice to have some charge going in.

On the trip south I only had to run the engine a few times for power, amd this was during the 5 day storm force blizzard/katabatic with heavy cloud and snow covering the panels.

The 80w or solar kept working well otherwise at 67 deg south, and even exceeded its power rating due to the low temp. But angling them right down to 85 degrees at times was critical to the success of the system.

[Kenomac]

Originally Posted by Dockhead

Will you be able to take it off and stow it while sailing? If I could find something like that, I'd be solar in a heartbeat.

Sent from my D6633 using Cruisers Sailing Forum mobile app

It won't make any difference while sailing and make a huge difference in practicality. Since the array will be lightweight and mounted over the dinghy sitting on the Davits, it won't even be seen when the boat is viewed from the side.

Removal during sailing would be silly. For most cruisers, ourselves included, very little time is actually spent sailing as opposed to enjoying quiet anchorages and site seeing.

[valhalla360]

In high latitudes, diesel with a small solar array seems a fairly practical arrangement.
- Run the diesel first thing in the morning for an hour or two to bulk charge and assuming it's set up, you can get hot water and maybe a little cabin heat off the engine cooling lines.
- With the bulk charging done by say 9am, a small solar array should be able to keep up with daytime loads (fridge shouldn't draw as much being cooler out) and top up by late afternoon eliminating concerns with damaging batteries by letting them drain too much.
- Because you are planning on a daily motor charging, you don't need to size the battery bank to accommodate multiple days of poor solar/wind charging, so you can use a smaller bank to begin with.


Wintertime might be more of an issue but I suspect most people stay at docks in that case where shore power can handle everything.

[Dockhead]

Originally Posted by Kenomac

It won't make any difference while sailing and make a huge difference in practicality. Since the array will be lightweight and mounted over the dinghy sitting on the Davits, it won't even be seen when the boat is viewed from the side.

Removal during sailing would be silly. For most cruisers, ourselves included, very little time is actually spent sailing as opposed to enjoying quiet anchorages and site seeing.

What you say about the amount of time at anchor vs sailing is certainly true, but dinghy, davits, and solar panels present a lot of surface to the wind -- and generate a lot of windage. Remember you are heeled going up wind. The wind also swirls around between dinghy and solar panels, generating turbulence and even more drag.

When I got my dinghy out of davits and folded up on my foredeck I noticed a huge difference in upwind performance, and it also has a big effect on boat motion. I'll never go back to sailing long passages with a dinghy in davits.

I saw a picture of a boat with walk-on-able solar panels built into the cabintop. I guess there would be shading issues but perhaps you could switch between sets of them to get the shaded ones offline.

That would be perfect for me. I don't really care about making my whole power budget with solar; I would just love to be able to top off the batteries without irrationally long generator runs.


Besides the generator, I get a lot of my power budget from my second alternator. The Oysters I saw all had the same setup as I do -- second school bus alternator for bulk power production -- I bet you also have this?

The alternator not only produces a lot of power every time you depart or enter a port, or do any motoring, but also helps to solve the "topping off problem", because it will give a sustained topping off charge any time you do much motoring. So I give my batteries a good topping off charge at least a couple times a week either by motoring or from shore power, which seems to work pretty well, if not perfectly. But I think I move more than you do -- we migrate about 3000 miles in the course of the summer, so that might play a role.

That of course also affects my attitude about sailing performance, as I often have to make hundreds of miles upwind. The trip back from Finland to the Solent is almost like Cabo San Lucas to Portland -- it's a hell of a bash, 1500 miles normally upwind. It really makes you look at windage differently.

[Dockhead]

Originally Posted by valhalla360

In high latitudes, diesel with a small solar array seems a fairly practical arrangement.
- Run the diesel first thing in the morning for an hour or two to bulk charge and assuming it's set up, you can get hot water and maybe a little cabin heat off the engine cooling lines.
- With the bulk charging done by say 9am, a small solar array should be able to keep up with daytime loads (fridge shouldn't draw as much being cooler out) and top up by late afternoon eliminating concerns with damaging batteries by letting them drain too much.
- Because you are planning on a daily motor charging, you don't need to size the battery bank to accommodate multiple days of poor solar/wind charging, so you can use a smaller bank to begin with.


Wintertime might be more of an issue but I suspect most people stay at docks in that case where shore power can handle everything.

Yes, I think diesel for bulk charging and solar for topping off is a great combination. They are totally complementary power sources.

I live on board in winter without shore power a fair amount -- at least a few months every year. I have no problem making my power budget with roughly 3 hours a day of generator use, but topping off the batteries is a problem I wish I didn't have. It means that I have to go into a port and hook up to shore power, at least once a week, if I'm not motoring anywhere. This is different from my summer pattern when I'm on the move all the time. It is a factor in deciding to move off my mooring and into a marina, which I always do by about January every year. Solar would definitely be an advantage, and even with the short days up here in winter, people get a decent amount of power. As someone mentioned, it is important to be able to angle them, at this latitude, especially in winter.



It should be mentioned at this point that solar power and lead-acid batteries go together like cookies and cream, because of the way lead-acid batteries are charged, with their very low charge acceptance rate at the end of the cycle, and because of the fact that they like to be held in fully charged condition.


This is all out the window when and if we ever change to LiFePo batteries. Those batteries DON'T like to be kept a full charge, and they have no tapering off of charge acceptance like lead acid batts do.

LiFePo batteries go together like cookies and cream, on the contrary, with large capacity diesel generating capacity, using this in the most efficient possible way. In fact, a giant alternator on your main engine may be all the power source you need, if you have LiFePo batts -- even the diesel generator starts to become obsolete.

So another thing to keep in mind is that solar may lose much of its relevance, if we ever make this switch.

[Kenomac]

Originally Posted by valhalla360

In high latitudes, diesel with a small solar array seems a fairly practical arrangement.
- Run the diesel first thing in the morning for an hour or two to bulk charge and assuming it's set up, you can get hot water and maybe a little cabin heat off the engine cooling lines.
- With the bulk charging done by say 9am, a small solar array should be able to keep up with daytime loads (fridge shouldn't draw as much being cooler out) and top up by late afternoon eliminating concerns with damaging batteries by letting them drain too much.
- Because you are planning on a daily motor charging, you don't need to size the battery bank to accommodate multiple days of poor solar/wind charging, so you can use a smaller bank to begin with.


Wintertime might be more of an issue but I suspect most people stay at docks in that case where shore power can handle everything.

Correct, that's exactly what we're trying to accomplish. Run the generator for one hour in the morning and 1/2 hour in the evening. Then let the solar take care of the rest.

[BobnCamie]

We were on our boat for near 2 years full time. Had 150 w. solar and a air max wind gen. kit. Was enough to power engel refridgeration but when we added another engel for freezer found we needed another 150w. solar. Wind was ok at roughly 450w.,I believe, but as far as I am concerned, throw wind away. Newer solar is so efficient even on cloudy days. 300 w. Of solar more than enough to power both Engels and everything else we had in boat. I would not allow a converter on the boat. Nothing but batteries killer ,IMOH, we powered all iPads,phones,etc. with 12 v. and very seldom had to start Honda gen to supplement the sun. Wind is problematic at best(wind either not enough or way too much) and one never tries to be in the wind much while at anchor. We are going back to boat in another year, plan is to add another 300w. of solar put in a 12v. water maker. Wind is way over rated anymore, as I said, in my opinion.


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[Kenomac]

Dockhead,

I can install a lot of solar and burn a lot of diesel for the price of only one lithium ion battery.

[Mike OReilly]

Originally Posted by DDabs

Get this man some coffee!

Nailed me DDabs, WUI: Writing Under the Influence

Meant to say "Often no sun days means more wind."

OK, my experience sailing in high latitudes (Lake Superior, just south of the 49th parallel) is that wind and solar are needed for long-term self sufficiency. Solar is great, but it only pumps serious amps for six to eight hours a day. Wind in anchorages is usually light, but the turbine turns 24 hrs. Over that time can produce significant amps. And of course, when it blow we've got more power than we can use.

The problems of wind are (for me) #1, Noise! And #2, Energy output. Both can be easily solved with the right generator. Our Silentwind is both quiet, and puts out lots of usable amps. There are other good ones out there as well. No ... not cheap, but neither is a good solar installation (I know, b/c I'm adding to ours right now).

Problem with solar on a boat (as Jim, Dockhead and others have said) is that it's hard to find enough good real estate for all the panels on the typical modest-sized cruising monohull. Added windage is a real issues, and shading is ever-present. This reduces the usable watts of most installations most of the time, even when the sun is shining bright.

A windgen typically takes up far less space, will produce 24 hours a day, and often works better when solar is working worse (overcast/stormy days). Like I said (or tried to say ), I'd prioritize solar first, but a good wind generator is a excellent compliment to any generating system.

[daletournier]

I have solar and a wind generator. Would never spend money on a wind generator again. I'd find space for another panel first. Obviously where you cruise has to be taken into account. When I was cruising between Cairns and lizard island the wind generator was great, since then I've just carted it around for 1000's of nm's.

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[Jsta_Rebel]

Originally Posted by vonchris7

Hi,

I am considering the options to provide power generation on my sailboat to live off the hook in the Caribbean. Looking for feedback/opinions on which is better - wind generator vs. solar panels.

I have both. 400 watts of solar, and 400 watts of wind generator. We live on the hook, and I promise you will need both to effectively live comfortably on the hook.

[Dockhead]

Originally Posted by Kenomac

Dockhead,

I can install a lot of solar and burn a lot of diesel for the price of only one lithium ion battery.

Absolutely. That's one of two reasons why I still use lead acid, and just dropped a bunch of money on a brand new set of lead acid batteries.

The other reason being that I don't want to be an alpha tester for not yet fully developed technology.

But eventually we will all be using them because the technology is clearly superior.