Wind Generators

Inachos486

Inachos486

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Can anyone please give me some advice regards best buy wind generater model for 48ft yacht with 5 domestic bats (100 hr each) based in the Ionian. Can generally rely on 4hrs plus steady afternoon winds 3/4/5 most days and more out of season. want to keep bats topped up without the need to reley on engine.
Thanks
 
depends to some extent on what lads you have, but given your large boat and large battery bank I'll stick my neck out and say you've probably got a lot of gadgets.

go for something pretty big - if your estimate of wind is reasonable, you can work out how much energy you'll get out of your shortlist of turbines using the power curve that's usually published in the brochure. it's probably worth estimating what you'll use daily, typical and worst case, and comparing these.

for a big boat/system i'd also suggest considering some solar too, so you have a bit of diversity of generation, and can keep your engine off even more.

some names to look at would be:
D400 by Eclectic energy (also consider the Duogen, same alternator and blades but doubles as a towed generator)
AirX
KISS
rutland 913 (a bit smaller)
the ampair range
Aero6gen

I have the first and chose it because it generates more at lower wind speeds, and is alegedly quieter than the competition, both points because of the large sweeped area and more blades than the competition. can't comment on the others.

hope that helps
 
You should consider Forgen too, in the larger size. They are silent and more or less no vibration. www.midsummerenergy.co.uk if I remember rightly, or google.

Otherwise, solar is likely to be much more effective. Ignore the rigid monocrystalline type, go for the thin semi-flexible type that can be walked on. They are a little less efficient, but more tolerant of shade. However, make sure you get an MPPT controller, not one of the older types, if you use solar panels.

Hope that helps

Mike
 
Inachos486 said:
Can anyone please give me some advice regards best buy wind generater model for 48ft yacht with 5 domestic bats (100 hr each) based in the Ionian. Can generally rely on 4hrs plus steady afternoon winds 3/4/5 most days and more out of season. want to keep bats topped up without the need to reley on engine.
Thanks
Click to expand...

I have a Rutland 913 on my 32ft boat which I am very happy with - no noise and good performance. I have often thought that if I were to have a bigger boat, I would fit two 913s on a rear portico (rather than one bigger wind generator from another manufacturer).

When sailing, my single 913 always generates more power when it is to "windward", so having two would give me the same output on both tacks.
 
The usual advice is buy solar for the med and wind for the windies. The output from wind generators isnt great until you get above 15 knots and in the med it doesnt blow that strong for a much of the time does it?

500 Ah of battery might easily self discharge by 40 to 50AH per week, more if the batteries are at all tired. so you need something that will put out say 10AH per 24 hr day. You usually reckon on maybe 5 hrs per 24 at the rated output so that suggests a solar panel of 25 watts. You would need 10 knots wind for 5 hours per day to get the same out of a Rutland 913
 
Bosun Higgs said:
The usual advice is buy solar for the med and wind for the windies. The output from wind generators isnt great until you get above 15 knots and in the med it doesnt blow that strong for a much of the time does it?
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10 knots of wind in the Adriatic gives me a substantial output from my Air-X, depending on my battery state. A rule of thumb for me is, that if there is enough wind to sail I can generate enough amps to balance my consumption (including a fridge).

If I have to motor then there is always enough power.

The problem comes at anchor when, as you have surmised, there are plenty of windless periods. That is when the solar panels are necessary.

And for those who complain about the Air-X noise disturbing others in the anchorage, that is so out-of-date. The later models such as mine are not so noisy and generally unobtrusive against other wind noise in the rigging when really churning out the amps. Not many other wind generators can deliver 400 watts - I once saw 51 amps on the ammeter in 25 knots of wind when the batteries were completely down.

I know that I would never bother with low-output generators that are only good for long-term trickle-charging and not keeping up with the high-current, real-time demand of a modern yacht's equipment.
 
You always were going to get a lot of differing opinions on this one. For what it's worth my advice would be to steer away from a Rutland 913. A good buy for trickle charging when you're off the boat during the week but not a viable option if you want to get usable power for day to day usage.

There are a lot of variables but put simply, power from a wind genny is proportional to the swept area so the interesting number is the square of the radius. The radius of a 913 is 455 mm (910mm diameter) so the swept area is Pi x 0.445^2 or 0.62m^2.

A D400 (like the one on my boat) has a radius of 550mm (1.1m Diameter) so the swept area is 0.95m^2 or 1.5 times the size of the Rutland. Air-x works out pretty much at 1m^2 or 5% more than the D400.

These were the systems available when I was going through this loop a few years ago, more have come onto the market since but the take-home message is go for the largest one you can get. You have a big boat so shouldn't be concerned about the size of the unit.

IF the Air-X really has quietened down then that looks like the best buy to me but I'd need some convincing. I went for a D400 because its top end output is similar to the Air-X but it is better at the lower end. It is though a heavier and more expensive unit and I would have gone for an Air-X if it wasn't for the noise.

The other variables are the generator and blade design (can't do much about that other than assume more £ means a better generator) and the height you pitch it. Ours is 2.5m up on a pole and in 10 knots of wind (that's at the masthead of course) I'll see 1-2A. At 20 knots it'll be 5-8A or more but the number is variable with wind shifts. Output is wind speed cubed so things get very good very quickly over 15 knots or so.

My experience with the 913 (I had one before the D400) is that in 10 knots you'll get nothing useful (less than 0.5A) and in 20 knots you might see 2-3A. If I'd bought it for trickle charging I'd have been happy but I wanted useful power and was quite disappointed given the glowing reports from people. The important point is to make sure whoever is recommending you a unit is using it in the same way you will be. Also make sure you know what height they have it pitched when giving you output readings. It might see twice the wind speed on the top of a mizzen compared to a pole behind the cockpit.
 
Bosun Higgs said:
500 Ah of battery might easily self discharge by 40 to 50AH per week, more if the batteries are at all tired. so you need something that will put out say 10AH per 24 hr day. You usually reckon on maybe 5 hrs per 24 at the rated output so that suggests a solar panel of 25 watts. You would need 10 knots wind for 5 hours per day to get the same out of a Rutland 913
Click to expand...

To give 10AH a day I think he will need a bigger panel assuming its permanenlty fitted and your not going to be altering the angle every hour to chase the sun. We see about 10AH a day from a 45w panel with some shadow from the boom at midday.

Pete
 
I have a 913 Rutland and it's reliable and quiet (well quiet to other people, it makes a loud rumbling noise through the boat) however a bit diappointing on performance. As stated already it gives nothing useful below about 12 knots and really needs 15 to do much. Even in a gale it's only putting out about 6 amps (12v) and at about 20 knots it's about 3. It's fine for me as I don't use much but I'd be disappointed if I was trying to keep a big load going.
 
Depends greatly on the boat and systems in use.
Full use of fridge(which is usually one of the major drains) means lots of amps req'd.
V. sunny areas without regular wind like the Med' will probably benefit from a fair sized solar panel more than a wind generator.
My 913 through a HRDX regulator keeps engine and domestic batteries very well topped up for all my basic needs for gps, plotter, navtex,ais,....without a fridge, but I agree with all said in previous posts regards output and I could have done with a small panel recently, when boat was left for two weeks when there was much sun and very little wind .......with a light left on!!.
For a large boat with lots of electrical demands including a fridge, that you spend a lot of time on, I would get bigger and better rather than skimp.
Good luck, I wish I had your problems
:)
 
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Barnac1e said:
10 knots of wind in the Adriatic gives me a substantial output from my Air-X, depending on my battery state. A rule of thumb for me is, that if there is enough wind to sail I can generate enough amps to balance my consumption (including a fridge).

If I have to motor then there is always enough power.

The problem comes at anchor when, as you have surmised, there are plenty of windless periods. That is when the solar panels are necessary.

And for those who complain about the Air-X noise disturbing others in the anchorage, that is so out-of-date. The later models such as mine are not so noisy and generally unobtrusive against other wind noise in the rigging when really churning out the amps. Not many other wind generators can deliver 400 watts - I once saw 51 amps on the ammeter in 25 knots of wind when the batteries were completely down.

I know that I would never bother with low-output generators that are only good for long-term trickle-charging and not keeping up with the high-current, real-time demand of a modern yacht's equipment.
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Interesting post though unless you need 20knots to sail, I doubt even an Air X will keep up with your domestic demand. My fridge alone averages 4 amps and thats in the UK.

But leaving that aside the AirX does clearly offer a lot more than the Rutland so it's of interest to me for my boat. Can you be a bit more specific about noise? My previous efforts with a windmill generated noise which was transmitted through the hull and it was junked for that reason alone . Can you hear the AirX through hull noise? Can you hear airborn noise? Do you have to turn the unit off at night? How do you have it mounted and what is your hull made of?
 
My parents have just fitted one of the new quieter Air-Breeze generators on their boat, it is moored just near my own.

When I helped fit it I was impressed by the mounting kit that had lots of rubber bushes to absorb noise and vibration. From what I can tell the Air breeze using the standard mounting kit does not transmit any vibration noise into the boat.

There is some noise from the blades, I would describe it as a swooshing sound but have only heard it in up to 15 kts and it wasn't obtrusive when sitting in the cockpit. I can imagine that on a windy night it could be noisy but then you have the option to switch it off with the flick of a switch.

Overall I was impressed by the build quality and it is considerably lighter than other wind gens on the market.
 
I reckon the mounting of the wind generator has much to do with noise transmitted through the boat.
Any resonance/vibration needs to be cushioned as close to the head of the generator as possible. Allow it to be transmitted through poles and stays/shrouds to the deck and you are magnifying the problems.
 
My Rutland 913 does 400 amp hours of start and house batteries, all of which have been charged by the wind genny for the last 4 years. An HRDX controller will also take inputs from solar panels and control that as well. We removed the solar panels because they were not needed, and the wind genny works day and night summer and winter. In the Ionian you may get a better input from the solar panels specially in the winter months..
 
Bosun Higgs said:
Interesting post though unless you need 20knots to sail, I doubt even an Air X will keep up with your domestic demand. My fridge alone averages 4 amps and thats in the UK.
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This summer I would say that typically I have had fairly consistent winds of 12-15 knots, which generates 3-4 Amps from the wind generator under sail with a well charged set of house batteries (I have 2x100A/h gel upgraded new this year). My Isotherm compressor fridge, the greatest current draw, is 48W on 12V, so say, 4 Amps when running (about 33:66 ratio of running/stopped when not opened as it is not set too cold).

Plotter and other instruments run at milliamps so not much current draw there and the other power-hungry item is the Raymarine S1 autopilot that when sailing doesn't correct the course too much as I have a stable long-keeler. I wouldn't like to even guess that consumption, but if I had to, about 3-4A/h. I'm happy to steer manually if I think it's all too much.

With winds from 15-20 knots - and that isn't always so infrequent in the northern/central Adriatic - there's power to spare.

Can you be a bit more specific about noise? My previous efforts with a windmill generated noise which was transmitted through the hull and it was junked for that reason alone . Can you hear the AirX through hull noise? Can you hear airborn noise? Do you have to turn the unit off at night? How do you have it mounted and what is your hull made of?
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There was a recent thread on this subject with my contribution here .

My Air-X is mounted on a 2.5m mast on the port quarter and braced against the pushpit and with two struts, all solid rubber isolated. There is NO vibration whatsoever transmitted to the hull, which is a very solid GRP layup, so there is no hull noise when generating.

AISmast.jpg

Can I hear the airborne noise? Yes, definitely, it is naturally tied to the windspeed, also the battery state - full battery and the vane is braked. That is perhaps the most annoying noise, the vane starts to speed up then the regulator decides it doesn't want anything and there's a clunk as it stops it.

Naturally, in a gale it does shriek a bit but that's when I throw the 'stop' switch and it just windmills silently.

Do I turn it off at night? Never, but then I sleep in the fore cabin, well away from the stern. But I've had crew sleeping in the saloon who said they didn't hear it.

HTH

Best, B.

P.S.
The OP double posted (always confusing) on the liveaboard forum - some new points of view over there.
 
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