47 replies to this topic

[Roleur]

When we were in Horta 2 weeks ago, I got to counting all of the wind generators on sailboats. Out of 200-300 boats in the marina, I counted 54 with wind generators. That seems like a huge percentage for a product that never seems to get great reviews (noise, lack of power in preferred anchorages, danger from rotating blades, etc.)

Horta, Azores I would think is a pretty good sample of cruising boats that are really out there cruising long distances. Not the easiest place to get to.

It gots me to wondering, are wind generators really all that? I know from our passage that if we had had a wind generator we never would have run the engine to charge the batteries as our deficit with a 140W solar panel was sometimes under 50Ah for a day.

[El Crapitano]

Wind generators are used because the alternatives are compromised too. Solar requires sun. Engine needs diesel and makes noise, and using a 60 hp engine to run a 300 A/hr alternator is not efficient. Boats have a finite supply of diesel too. Harnessing wind decreases reliance on solar and engine. Given that more and more electronics are creeping onto boats for navigation and communication, keeping batteries charged is an ever increasing priority.

[Roleur]

Wind generators are used because the alternatives are compromised too. Solar requires sun. Engine needs diesel and makes noise, and using a 60 hp engine to run a 300 A/hr alternator is not efficient. Boats have a finite supply of diesel too. Harnessing wind decreases reliance on solar and engine. Given that more and more electronics are creeping onto boats for navigation and communication, keeping batteries charged is an ever increasing priority.

All true, but even given all the truths it seemed that wind generators have been very rarely used. Maybe that has changed since I last made an assessment or maybe it is a European/US thing. I find it surprising because in cruising the West Coast of the US, Salish Sea, Southern Cal, and Mexico, I would have said the number of wind generators per cruising boat was more like 1 in 100, not 1 in 5.

[savoir]

Wind generators are a European thing - British in particular.

[MR.CLEAN]

There is a direct correlation between the price of diesel and the usage of whirlygigs. US & Mex = cheap ass fuel. Azores, not so much. I haven't been there in a while, but even back in early 2000s it was the equivalent of around 9$ a gallon for diesel, and even then, maybe a quarter of cruisers had wind gennies. We did on a little 38 footer, and used it lots.

[Schnick]

Wind generators are used because the alternatives are compromised too. Solar requires sun. Engine needs diesel and makes noise, and using a 60 hp engine to run a 300 A/hr alternator is not efficient. Boats have a finite supply of diesel too. Harnessing wind decreases reliance on solar and engine. Given that more and more electronics are creeping onto boats for navigation and communication, keeping batteries charged is an ever increasing priority.

All true, but even given all the truths it seemed that wind generators have been very rarely used. Maybe that has changed since I last made an assessment or maybe it is a European/US thing. I find it surprising because in cruising the West Coast of the US, Salish Sea, Southern Cal, and Mexico, I would have said the number of wind generators per cruising boat was more like 1 in 100, not 1 in 5.

In the 'Salish Sea' as you call it, or generally anywhere in the PNW, there is a fair bit of motoring going on and the distance between docks with power is typically under 10 miles. I think that alternative energy sources are still very slow to catch on here, and it also seems to me that even most hard core sailors end up motoring more than enough to keep the batteries topped off unless they are going fully offshore. Rainy, not that windy (in summer at least) climate doesn't really do much for Solar or wind power schemes.

[PNW Matt B]

BTW, it's not just Roleur - that's the official name for the connected waterways from Desolation Sound south to Olympia, as of late 2009/early 2010. Salish Sea

[Schnick]

BTW, it's not just Roleur - that's the official name for the connected waterways from Desolation Sound south to Olympia, as of late 2009/early 2010. Salish Sea

Yeah I know but its still silly.

[redviking]

As a five year veteran of the battery wars, I can tell you that a windgen is by far the most effective source of alternative energy. Solar is cool, we have two 85 watt panels, but the windgen rules. Two alternators on the engine help, and a set of Rolls batteries rounds out the power package. The only problem is the noise and slight vibration... Turn it on when you leave, and off at night please... I know owners who run their windgens at a dock. Poor form.

[Keith]

The combination of wind power and solar are usually found on full-time cruising boats.

Its a great way to keep the batteries topped up . In the south pacific, there were many boats with wind generators and solar.

Most of these cruisers, from all over the globe had been out cruising for a long time.

[Maine Sail]

They have gotten a lot better in the last few years. There is still some junk out there so don't buy on price alone.

The three I like are:

Eclectic Energy D400 (amazingly quiet and robustly built)

Superwind 350

Air-Maax (well built, looks very promising but have not installed one or played with one up close just at a show)



If putting one on my own boat right now it would be an Eclectic Energy D400. I have installed wind gens that have produced in excess of 125 Ah's per day when the wind is 15+.... Not bad.... Today it was blowing 14+ for over 8 hours and was bright and sunny any boat with wind and solar would have done very, very well today...

[Blye]

The combination of wind power and solar are usually found on full-time cruising boats.

Its a great way to keep the batteries topped up . In the south pacific, there were many boats with wind generators and solar.

Most of these cruisers, from all over the globe had been out cruising for a long time.

IMHO the more choices you have available, the better you will be able to keep the steaks chilled and make ice for that sundowner.

We have both wind and solar and they each fill in now and then... but there's the crux, even together sailing the Caribbean/ East Coast / Great Lakes, they are not charging 100% of our meager needs all the time.

[Roleur]

The cost of diesel in Europe versus the US makes a lot of sense regarding the difference in popularity.

I really like the D400. I've seen several of them and they seem to be near silent. Practical Boat Owner liked them as well. It's going on the "list".

[Jon Eisberg]

Wind generators are a European thing - British in particular.

I don't know, if you travel up and down the US East coast, they sure have become popular among snowbirds spending heading south for the winter and beyond... Hell, many boats are now sporting more than one...




The Bahamas in winter are the perfect place for wind power, good breezes and open anchorages with no high topography surrounding them, my generator is very effective there... Nevertheless, I'm struggling with permanently installing something as unsightly as a wind generator on my boat, and am still content to live with the hassle of rigging mine when it's needed...





The D400 is almost spooky, how quiet it is... However, it is a massive beast and rather ugly to my eye, and would be incredibly conspicuous on a boat the size of mine... At this point, if I were gonna go with a permanent installation, I'd lean towards the Silentwind... I've seen a couple out there, they're basically identical to the Air Marine, but with carbon fiber blades that are very quiet, the noise level was quite acceptable...

http://www.silentwindgenerator.com/index.php?language=en&osCsid=ceb4e5fa934b734aae51d87b3be58574

[savoir]

I had a Rutland 913 on my previous boat. Every aspect was great BUT ( there's always a "but" ) the power output was half what the manufacturer claimed. My best was 9 amps. Such a shame because it was very quiet and reliable.

After that time I read everything I could find on the subject and the two that came up tops were Superwind and D400. Please everybody don't whatever you do get an AirX. The noise will drive me, and everyone else within 50 yards, kerayzee.

[Roleur]

Jon,

Beautiful pic. We had a guy in front of us in Horta with two panels and two wind generators and yet he was running a damn Honda generator 4 hours a day every day. WTF? This was a modest boat too. He must have been growing something down below to need that much power.

I completely agree on the overall aesthetics of a permanent mount, although to my eye the D400 is the most attractive of the bunch, but I don't see an at anchor solution achieving what I'd want to achieve which is silent sailing 24/7. Running the diesel for an hour when it is blowing 20 and we are making 8 knots just sucks.

Everything on a boat is a compromise. Wind generators certainly are.

[Ajax]

I simply loathe ungainly, permanently installed shit cluttering up the lines of my boat. We all joke about the COTB awards.

What I'd like to see, is a stowable wind turbine. Basically, the hub will be easily removeable, with collapsible or removeable blades, a telescoping pole that locks into a sturdy, but not too large stern bracket, with a robust, spray proof power connector.

Compromises I would be willing to accept in this configuration: lower power output than permanent wind turbines, some degree of noise, a slightly higher cost (provided the quality is good), maybe some extra weight.

I also have this idea in my brain for a wind turbine that mounts on the mast. It's limitation is that you could only use it at anchor. However, it would eliminate heavy, unsightly mounting hardware on the stern in favor of a simple tracked collar on the mast. You attach the hub, flip out the blades, hang the wind turbine on the collar, plug it in, and you can move the wind turbine around on the mast to wherever the wind is blowing from.

Pros: Lightweight, easy to set up, less hardware, stowable.
Cons: Mainly for use while stationary, requires manual positioning, smaller size means lower power output.

I dunno... dumb idea?

[Ishmael]

I simply loathe ungainly, permanently installed shit cluttering up the lines of my boat. We all joke about the COTB awards.

What I'd like to see, is a stowable wind turbine. Basically, the hub will be easily removeable, with collapsible or removeable blades, a telescoping pole that locks into a sturdy, but not too large stern bracket, with a robust, spray proof power connector.

Compromises I would be willing to accept in this configuration: lower power output than permanent wind turbines, some degree of noise, a slightly higher cost (provided the quality is good), maybe some extra weight.

I also have this idea in my brain for a wind turbine that mounts on the mast. It's limitation is that you could only use it at anchor. However, it would eliminate heavy, unsightly mounting hardware on the stern in favor of a simple tracked collar on the mast. You attach the hub, flip out the blades, hang the wind turbine on the collar, plug it in, and you can move the wind turbine around on the mast to wherever the wind is blowing from.

Pros: Lightweight, easy to set up, less hardware, stowable.
Cons: Mainly for use while stationary, requires manual positioning, smaller size means lower power output.

I dunno... dumb idea?

Not at all. If you look at the picture of Jon's boat, he has a stowable wind turbine hung in the rigging.

[Ajax]

Oh... I'm at work, can't see the photos. My faux pas.

[Roleur]

Oh... I'm at work, can't see the photos. My faux pas.

It's a FourWinds generator, I believe. Much longer blades than the typical permanent mount, which means it cranks out the juice.

But yes, you are correct. I hate the idea of messing up the lines of our boat as I find them particularly appealing in that sleek, simple sort of way.

[Glitter In The Eye]

any of you guys have a big ugly used one you want to sell? I need one for our tailgate bus for football season, we use solar panels but they dont work for night games and the blender, 50 inch TV, XBOX with Rock Band on for the kids drains our system...we use a small honda gen but would like to add wind.

[Beau.Vrolyk]

My biggest complaint about wind generators is that I spend a lot of effort to anchor in a place that doesn't have any wind, and really prefer it.... do I put one up and then go anchor out in the breeze (which around here means out in the bumps too)? Specific examples: Wind speed off shore of Capitola on a "normal" summer afternoon is 20k. Wind speed in the cover where everyone anchors is 5k. Wind speed in Ayala Cove on Angel Island where everyone picks up buoys is about 5k. Wind speed off the point sheltering Ayala Cover 20+ knots.

Wind generators just don't match up with the places I want to spend my time on the hook. They work in areas where the geography is relatively low and lets the breeze blow through but aren't worth much in bumpy areas or in places like the PNW where there's typically not a lot of wind. That paucity of places where they work well makes them awfully expensive for the watts produced.

That said, they'd be great in the Tuamotus, low coral atolls. However, they'd suck in the Marquesas or in most of the Society Islands for the reason I stated at the beginning of the post. Similarly, they would work in a few places in New Zealand and be useless in most of the nicer coves.

I used to sit an drink my morning coffee while anchored at Uapu in the Marquesas and thank god that we were in the lee of the island so I didn't have to listen to the wind generators moaning.

BV

[Roleur]

BV,

You are bringing up all of the things I've heard for years, which is why it was such a shock to see all these wind generators in Horta. 1 + 1 is not equalling 2 here. If all of what you say is true (and exactly what I have believed) then why are there so many on all these boats that are out there really cruising? It's a bit of mystery to me. Maybe the wind in the anchorages are different over here?

My biggest complaint about wind generators is that I spend a lot of effort to anchor in a place that doesn't have any wind, and really prefer it.... do I put one up and then go anchor out in the breeze (which around here means out in the bumps too)? Specific examples: Wind speed off shore of Capitola on a "normal" summer afternoon is 20k. Wind speed in the cover where everyone anchors is 5k. Wind speed in Ayala Cove on Angel Island where everyone picks up buoys is about 5k. Wind speed off the point sheltering Ayala Cover 20+ knots.

Wind generators just don't match up with the places I want to spend my time on the hook. They work in areas where the geography is relatively low and lets the breeze blow through but aren't worth much in bumpy areas or in places like the PNW where there's typically not a lot of wind. That paucity of places where they work well makes them awfully expensive for the watts produced.

That said, they'd be great in the Tuamotus, low coral atolls. However, they'd suck in the Marquesas or in most of the Society Islands for the reason I stated at the beginning of the post. Similarly, they would work in a few places in New Zealand and be useless in most of the nicer coves.

I used to sit an drink my morning coffee while anchored at Uapu in the Marquesas and thank god that we were in the lee of the island so I didn't have to listen to the wind generators moaning.

BV

[Anomaly2]

Jon,

What are you using for your solar panel mounts, do you have a closer picture? Thx.


[quote name='Jon Eisberg' timestamp='1343734173' post='3807091'



[/quote]

[Beau.Vrolyk]

BV,

You are bringing up all of the things I've heard for years, which is why it was such a shock to see all these wind generators in Horta. 1 + 1 is not equalling 2 here. If all of what you say is true (and exactly what I have believed) then why are there so many on all these boats that are out there really cruising? It's a bit of mystery to me. Maybe the wind in the anchorages are different over here?

My biggest complaint about wind generators is that I spend a lot of effort to anchor in a place that doesn't have any wind, and really prefer it.... do I put one up and then go anchor out in the breeze (which around here means out in the bumps too)? Specific examples: Wind speed off shore of Capitola on a "normal" summer afternoon is 20k. Wind speed in the cover where everyone anchors is 5k. Wind speed in Ayala Cove on Angel Island where everyone picks up buoys is about 5k. Wind speed off the point sheltering Ayala Cover 20+ knots.

Wind generators just don't match up with the places I want to spend my time on the hook. They work in areas where the geography is relatively low and lets the breeze blow through but aren't worth much in bumpy areas or in places like the PNW where there's typically not a lot of wind. That paucity of places where they work well makes them awfully expensive for the watts produced.

That said, they'd be great in the Tuamotus, low coral atolls. However, they'd suck in the Marquesas or in most of the Society Islands for the reason I stated at the beginning of the post. Similarly, they would work in a few places in New Zealand and be useless in most of the nicer coves.

I used to sit an drink my morning coffee while anchored at Uapu in the Marquesas and thank god that we were in the lee of the island so I didn't have to listen to the wind generators moaning.

BV

Roleur,

I don't know why you're seeing what you're seeing. It is certainly true that there are a few windy places, but they're sure not where I'd like to anchor. As I said, in low places like Bermuda, the Bahamas, and all the coral atolls of the S. Pac. a windmill would work fine, as it would on the Dutch coastline where the tallest thing around is a Billboard on the highway. I can't figure it out.

Beau

[Moonduster]

In my experience, the only place in the world that wind generators make any sense (and even then, not much) is in the South Pacific, when anchored inside atoll lagoons fully exposed to the trade winds.

Every time I do the math on solar, wind and towing generators, the best solution is always an 8HP diesel auxiliary with a belt driven alternator and water maker. A 1KW Honda generator is a close second, but I hate carrying the gasoline around.

[WHL]

Saw lots of wind gens over the last 2 weeks between Newport and Maine. The D400 was silent compared to all the others.

[Roleur]

In my experience, the only place in the world that wind generators make any sense (and even then, not much) is in the South Pacific, when anchored inside atoll lagoons fully exposed to the trade winds.

Every time I do the math on solar, wind and towing generators, the best solution is always an 8HP diesel auxiliary with a belt driven alternator and water maker. A 1KW Honda generator is a close second, but I hate carrying the gasoline around.

I think it is very fair to say that for some it is not just a math question. I simply will not have a boat with a diesel/petrol generator. Period. I'll stay at home before I would go that route. But for some it makes perfect sense and that is fine. Just not for me. If it is all about the math a sailboat is horrible idea to begin with, so for me, turning this into a simple math exercise doesn't really make sense.

As Clean mentioned earlier though the math might look different if you are using European diesel prices that run about $9/gallon.

[MR.CLEAN]

Remember too that there is another, very efficient solution now for those that actually sail long distances - it blows away the towing screws that have been used for decades. And note that two of this year's Vendee boats - which, by the way, need to not only run computers, BGAN satcomms, and fucking canting keels - are locking up their emergency diesel can (20 liters) and racing non-stop around the world without touching fossil fuels. I think their target is 85% power coming from their W&S Hydrogens and the other 15 coming from wind gens (over 20 knots of boatspeed they usually pull the gens out of the water) and solar for the doldrums.

But at anchor, I'll stand by what I saw when cruising Europe from Scotland to Sardinia: Wind power works pretty damned well if you have the right unit, and when it's not windy, it's usually sunny enough to get good juice out of big panels.

Then again, those li'l tiny 1-cylinder DC gensets (we used to call the 1-cylinders "thumpers") are pretty cool too.

[Jon Eisberg]

Oh... I'm at work, can't see the photos. My faux pas.

It's a FourWinds generator, I believe. Much longer blades than the typical permanent mount, which means it cranks out the juice.

But yes, you are correct. I hate the idea of messing up the lines of our boat as I find them particularly appealing in that sleek, simple sort of way.

Mine is actually from Hamilton Ferris... One of the reasons I went with theirs is the dual function that it can serve as a towed water generator, as well... That is actually by far the most effective means for me of generating power, especially as batteries are approaching full charge, water appears to trump wind in terms of "forcing" more amps through towards the end...

I'll never understand why water generators are not more popular, at least among American cruisers... They consistently get high marks in surveys like the ARC gear reviews. Lots of stories out there about spinners getting taken by sharks, etc, but I believe most of them are bullshit... For open water passages, far enough offshore to be clear of areas of fishing buoys/lobster traps and whatnot, mine works beautifully. I'd love one of the new units from Watt & Sea, but that price is way out of my league... (grin)

Your boat is looking very sweet, I can see why you'd want to keep the look clean. If I do decide to go with a pole mounted windgen, I'd still definitely try to make it as easily removeable/stowable as possible, perhaps with the use of a carbon pole that would simply drop into a bracket or slot of some sort. Wind gens do appear to have considerable value underway, it appears that for Matt Rutherford's voyage, for example, it was his primary means of power generation...

I think it is very fair to say that for some it is not just a math question. I simply will not have a boat with a diesel/petrol generator. Period. I'll stay at home before I would go that route. But for some it makes perfect sense and that is fine. Just not for me.

Really nice to hear at least someone out there still expressing that point of view.... IMHO, one of the most depressing trends I'm seeing today, is the ever-increasing prevalence of freakin' Honda 2000s on the decks of boats in anchorages everywhere...

[Jon Eisberg]

Jon,

What are you using for your solar panel mounts, do you have a closer picture? Thx.

My panels are intended to be deployed temporarily, as well, and are stowed below decks when not in use...

To get the max out of such a setup, and a relatively modest array, you must be able to articulate them fully. Particularly in a place like the Bahamas in winter, many cruisers wind up being very surprised how little time each day the sun is actually high overhead...

I use a sort of ball-joint mount with a locking lever made by Magma, designed for holding their bait/fillet tables in a rod holder... I have a pair of rod holders on my pushpit, and extensions that raise the height of the panels... there's a fair amount of wide angle distortion in this pic, they're not as high as it may look, but I usually place them lower on a shorter set of extensions, anyway...




I generally don't have the panels set up when sailing offshore, certainly not if I'm expecting any weather... But I can if I want to, with a tiller-steered boat they're pretty much out of the way, the only thing they really interfere with might be my movement back to the stern to fiddle with the vane...

All in all I'm very happy with this set up, but it's probably only a workable arrangement for a small boat with modest electrical demands, to begin with...

[Anomaly2]

Thanks Jon. I'm very much in the smaller boat (33'), very modest electrical system/demands and have the makings of a small array underway. Tiller-steered.... So I find that many of your "solutions" are very relevant and appealing. The rod-holder swivel mounts are a case in point. I know that James Baldwin offers a custom fabricated swivel mount but your approach accomplishes the same thing and I like the stowability factor.

Love the shot of your panels and the Sailomat!

Jon,

What are you using for your solar panel mounts, do you have a closer picture? Thx.

My panels are intended to be deployed temporarily, as well, and are stowed below decks when not in use...

To get the max out of such a setup, and a relatively modest array, you must be able to articulate them fully. Particularly in a place like the Bahamas in winter, many cruisers wind up being very surprised how little time each day the sun is actually high overhead...

I use a sort of ball-joint mount with a locking lever made by Magma, designed for holding their bait/fillet tables in a rod holder... I have a pair of rod holders on my pushpit, and extensions that raise the height of the panels... there's a fair amount of wide angle distortion in this pic, they're not as high as it may look, but I usually place them lower on a shorter set of extensions, anyway..

[Diarmuid]

It may be that wind turbines haven't got so much better -- they have, incrementally, but their fundamental issues for boating remain unchanged. Rather, wind turbine marketing has sharpened up its game. Sailboat owners are easy touches for wind power: we like wind-driven stuff (duh); we're always trying to live a condominium lifestyle on a 36'x12' tube & so always desperate for electrons; and we're up there with golfers for throwing money at problems.

I love our home wind turbine. A recent, unprecedented spell of windless days has proven just how essential it is to our power needs. Solar's great, but wind does the grunt work around here. No wind = sad batteries. Still, I'm not seriously considering a wind genny for the cruising boat when we buy one. The math on any turbine under ~8' diameter is really dismal, and 8' is impractical for any boat smaller than a Wally. Tow generator on passage, solar w/small generator at anchor, I guess. PV prices and power densities are improving lots faster than wind turbines are.

Wind remains a viable choice for some sailors. As with anything energy-related, tho, you gotta start by casting a cold eye on demand. How much power are you using, & how much do you really need to live happily? Do recall that not very long ago, boats sailed all over the world without 1000Ah of AGMs, twinned HO alternators, a Panda in the laz, and a 30gph watermaker.

The calculus changes for each person. But we've lived with a wind genny for nine years now. I respect both its capabilities and limitations, & present inclination sez we don't want one on our sailboat. Might change our minds; but nothing changes the brutal realities of swept area. Twelve square feet isn't gonna make much ice, not outside the Bahamas in December. If you are all about the Bahamas in December, getchoo one! Hell getchoo two, like that boat pictured above. That way there's a fair chance one will be working.

[blackjenner]

I'm watching all this very closely, as we continue to outfit Brigadoon for a circumnavigation in a few years. I'm holding off on purchases of stuff we don't need now, but will need later. Technology seems to be really moving ahead. I see quieter wind generators, smaller water generators, and flexible and efficient solar panels.

I think it's likely that, when we leave the PNW (known for low winds in the summer and cloudy days most of the winter) we will make use of passive generation of electrons for our battery. It makes sense not to have to run an engine or a generator just to top the batteries.

So, we are playing a waiting game, watching the technology, and working out the right electric package (batteries, solar, wind/water gen) that can get us around the world.

[Kenny Dumas]

Diarmuid, please tell us about your home wind generator.

[soma]

I was a bit surprised to see the MOD70's had wind gens. Obviously they sail at apparent wind speeds much higher than most of us experience on the stormiest of nights. with that said, though, the hydro gens are fantastically effective.

[savoir]

Careful. A cruising version Wattandsea was 7k last year and probably more now. The racing ones are carbon and cost more again.

[Diarmuid]

Diarmuid, please tell us about your home wind generator.

Not much to tell. It's a Bergey XL1 1000W unit, 8.2' diameter, ~70lbs not including the 5" diameter guyed tower. Important facts #1 & #2: higher-output turbines are heavy, and their lateral loads require more than a 1.5" monopole. Or you get this:



Upper guy wire fatigued at a cable clamp.

Output is 3-phase wild AC, rectified at the turbine to DC. Slip rings allow the turbine to yaw w/out wrapping the wires. Important fact #3: get water or wind-driven snow in slip rings, and you have a direct short of 40 amps. Looks like this:



The Bergey uses extruded FG blades -- no twist, no taper, tho losses are less than you might think -- which might be okay if they attached them properly. Blade failure at the roots is systemic with these machines. Important fact #4: long blades spinning at 600-1000 RPM need to be bonded to the hub really well.



Bergey uses a boost MPPT controller to start generating at around 7mph; real amps don't begin flowing til ~14mph (which, by the way, is true of any wind turbine, regardless of scale -- lower winds simply don't have enough power for the turbine to reap). When it's really cooking (25-30 mph), you can see 45-50A at 24VDC. That's real output! Keep it up for three days straight, and you are ready for a trip to the copper recycling center:



Important fact #5: High amperage, low voltage DC power is hell on conductors.

You are probably getting the general drift, here....

[MR.CLEAN]

Careful. A cruising version Wattandsea was 7k last year and probably more now. The racing ones are carbon and cost more again.

$20k++ for the racing version. Big difference is that it automatically adjusts pitch for maximum efficiency, and creates significantly less drag. Though the cruising version makes a lot less drag anyway compared to a prop-on-a-rope generator.

Shocking amounts of juice come off these things.

[narecet]

In the design of the Acciona Open 60, they worked out expected available energy or amounts obtained (the meaning is not clear) from the solar, wind, and hydrogenerator systems according to the different parts of the voyage. It was an interesting chart: different sections of the circumnavigation were expected to have quite different balances of power available. Sometimes much more was expected to be available from the wind generators than from the hydrogenerators.

http://www.accionasa.../Acciona-lr.pdf (the last page)

The text indicates that actual draw of power isn't expected to be as shown in the chart:

While the maker states these [the Watt and Sea hydrogenerators] have a start-up speed of seven knots, Javier Sanso says he does not use the hydrogenator below ten knots' boat speed because of drag. Each leg produces 450W at 12 knots of boat speed. The output levels off at higher speeds through the use of a variable-pitch propeller that automatically feathers the propeller blades to minimise drag.

Two 350W Air X wind generators can be fitted on poles above the transom, although Sanso says he will only ever use one generator fitted to windward and is more likely to use the hydrogenator owing to the units' high windage.

Perhaps for example with the wind across the beam, then the windage of the wind turbines doesn't matter much and might be more acceptable than drag from the hydrogenerators.

But for that matter, exactly why say 30 lb of windage upwind would be worse than 30 lb of drag from the hydrogenerators, I can't figure. Downwind, the wind turbines have the advantage, if there's still enough apparent wind I suppose.

Don't know. Interesting.

Anyway, it may be that even with the best currently available solar and hydrogenerator systems, wind turbines still have a worthwhile place in at least some areas, not just at some moorings. Probably not that many have both a high efficiency hydrogenerator and a high efficiency wind turbine to be able to make the comparison.

[Diarmuid]

BTW, I just helped a friend install a Kestrel 3kW turby. Seriously nice piece of kit. It's made by a subsidiary of Eveready Batteries, so there is some R&D money in play. Most wind turbine companies to date have been garage-shop affairs. Kestrel ticks the right boxes for me: good blade shape, passive blade pitching, axial-flux alternators, and a tip-speed ratio in the sweet spot between output and liveability.

His Kestrel is on a tilt-up monopole the diameter of a mature douglas fir. Which it needs to be, since the turbine weighs 500# and experiences 340# of lateral thrust in 20kt winds. Think about what that would do to a sailboat's handling: that's why there's a practical cap of ~600W peak output on marine wind turbines. From which sized machine you can expect an average output of ~25% peak -- call it 150W in a reliably breezy location (mean wind speed 14kts). That would provide 3.6 kWh/day, less losses at charge controller (in) and batteries (out), figure a shade under 3kWh/day useable power. About half that goes to refrigeration at anchor; autopilot would use most of the rest on passage. Output drops steeply in lesser wind regimes.

Kestrel makes a little 600W unit that looks like an update of the venerable Rutland, but you can be sure it has many of the same performance compromises of any small turbine. Specifically, at less than 7' diameter you are forced to choose between torque (lots of fat blades) and a low speed alternator, or low solidity and a high-speed alternator. The latter (see Air-X) spools up fast (TSR ~10) but is prone to failure; the former has a nice, low cut-in speed but struggles to reach max output due to blade drag. Both count on turbulence to govern speed: no room for pitching or furling mechanisms in the small hub. The Air-X also uses alternator braking. Which means dead-shorting the stator to slow the blades. See photo of blackened stator, above. Drag-governing (or aeroelastic blades) is inherently noisy.

Dunno if the little Kestrel is marinized. Weighs almost 70#, too. Ouch.

[Ajax]

Bumping this to push the spam further down the list.

[Diarmuid]

Perhaps for example with the wind across the beam, then the windage of the wind turbines doesn't matter much and might be more acceptable than drag from the hydrogenerators.

But for that matter, exactly why say 30 lb of windage upwind would be worse than 30 lb of drag from the hydrogenerators, I can't figure. Downwind, the wind turbines have the advantage, if there's still enough apparent wind I suppose.

Because the weight and windage of a wind turbine are at the top of a tall pole. That's where the good wind is; since power increases as the cube of wind speed, a couple knots makes a huge difference in output. So you want to get that genny up,up,up.

Then you have a heavy, air-resistant mass high aloft (and probably far astern) imparting both heeling and yawing forces to your boat and increasing rolling & pitching moment. See my earlier comment re: the effect on boat handling.

A hydrogenerator's only effect is drag, and drag more-or-less in line with the boat's major axis. Other hydro advantages:

* Water is ~100 times denser than air, so it contains 100 times the power and energy of an equal volume of air moving at the same speed. That means you can make more watts with a much smaller diameter rotor at a lower fluid speed than you can with a wind turbine. Water is a bit 'stickier' than air, tho. You need excellent rotor design, and you will need to keep those blades clean.

* Water flowing over a hydro-gen is only coming from one direction. There's no loss as the unit 'hunts' to find a shifting wind (an effect called hysteresis) or swings around due to wave action or heeling. You don't face the complexity of slip rings or the nightmare of twisted wires.

* Further, water flowing over the hydro-gen is moving within a narrower speed range than wind moves in, for a given boat design. Your cruising boat is probably moving between 4 and 10kts: that still represents a huge span of kinetic energy, but it is much easier to design a compromise rotor and alternator for that distribution than for the 4-40kt range of apparent wind speeds you will observe. Pitchable blades are sweet, but they add tons of complexity & cost. Fixed blades & predictable flow rates are a good pairing.

* Hydrogens are easy to raise and deploy. They carry their weight low. When batts are full, they can be allowed to freewheel w/out overspeed noise or the risk of throwing blades. They are water-cooled, water being a much better conductor of heat than air.

Downsides are they always add drag in a negative direction, they are immersed in water, and they are prone to strike damage. Or shark damage, possibly. Also, more junk on the transom.

I'd be curious about the feasibility of a hydro-gen being faired into a keel or rudder assembly. Sort of an end-plate/bulb design, with propeller. It'd be prone to damage in groundings, and there'd be fouling issues. Huh. Be nice to get it down deep, tho. Down in the clean, heavy water.

[Ajax]

Hmmmmmmm!

[Diarmuid]

Hmmmmmmm!

Of course, we should not overlook an obvious point, here -- most cruising boats (unlike RTW racers) spend ... what ... 80% of their time at anchor, in a slip, or on a mooring ball. That sound right? Hydro does squat-all for you then. A wind turbine will do some, depending on the anchorage & your willingness to listen to the fucker squeal and moan at 2AM. Sitting still is where solar PV really comes into its own, tho. I'm doing lots of thinking about how to increase solar array size at anchor. Maybe incorporating either rigid or flexible panels into a harbor awning design. Get shade and power at once.

Gonna be five-ten (twenty?) more years before film PV technology gets there, tho. It's been 'just over the horizon now' forever.

[Zonker]

Why wind generators in some locales?

I think the Brits/Northern Europeans fit wind generators because they never see the sun. When they get to the Med or cross the Atlantic to the Caribbean, they kick themselves cause it's sunny a lot. On a typical downwind passage, the wind generators are often loafing in lightish apparent winds. At anchor, you try to find a sheltered harbour. So the wind generator isn't usually running in 15+ knots of wind.

Actual time spent sailing
80% of time at anchor is probably actually low, unless you are crossing the Pacific in one season like we did.

Example:
Left Mexico April 9; arrived Australia Nov 16th = about 220 days. Total distance sailed say 8500 miles. We average about 160-165 miles/day at sea, thus 53-51 days at sea or 24%. All our other cruising has spent way more time at anchor... I bet typical is closer to 90%.

We've got friends that spent 4 years cruising Mexico rather slowly. In 4 years they did 10,000 miles. They have a kinda slow boat that on a good day might make 100 miles/day. So 100 days of sailing in 4 years = 6.8% time sailing.

Power consumption:
Time at anchor is where the computer is getting a steady workout. Like 8 hrs/day when my wife or I am working. Contrary to most folks at sea we use LESS power. At sea the only power is the GPS (neglible), the autopilot (~2-3A), and LED tricolor at night (neglible). Maybe 20 minutes of time on the ham sending/getting Pactor weather. Fridge is the same at anchor or on passage. Lighting interior is less at sea.

Generation:
I prefer primarily solar (we have 420 W). No maintenance and it's almost guaranteed that the sun rises every day. Even on very cloudy days you get some power, even if it's only 2 or 3A.

I wouldn't mind a small wind generator if I could find a place to mount it where it wouldn't shade the solar panels.

I'm not a fan of water generators for the % of time at anchor I noted above. Great if you're a Vendee racer, not if you're a typical cruiser.

[narecet]

Perhaps for example with the wind across the beam, then the windage of the wind turbines doesn't matter much and might be more acceptable than drag from the hydrogenerators.

But for that matter, exactly why say 30 lb of windage upwind would be worse than 30 lb of drag from the hydrogenerators, I can't figure. Downwind, the wind turbines have the advantage, if there's still enough apparent wind I suppose.

Because the weight and windage of a wind turbine are at the top of a tall pole. That's where the good wind is; since power increases as the cube of wind speed, a couple knots makes a huge difference in output. So you want to get that genny up,up,up.

Then you have a heavy, air-resistant mass high aloft (and probably far astern) imparting both heeling and yawing forces to your boat and increasing rolling & pitching moment. See my earlier comment re: the effect on boat handling.

A hydrogenerator's only effect is drag, and drag more-or-less in line with the boat's major axis. Other hydro advantages:

* Water is ~100 times denser than air, so it contains 100 times the power and energy of an equal volume of air moving at the same speed. That means you can make more watts with a much smaller diameter rotor at a lower fluid speed than you can with a wind turbine. Water is a bit 'stickier' than air, tho. You need excellent rotor design, and you will need to keep those blades clean.

* Water flowing over a hydro-gen is only coming from one direction. There's no loss as the unit 'hunts' to find a shifting wind (an effect called hysteresis) or swings around due to wave action or heeling. You don't face the complexity of slip rings or the nightmare of twisted wires.

* Further, water flowing over the hydro-gen is moving within a narrower speed range than wind moves in, for a given boat design. Your cruising boat is probably moving between 4 and 10kts: that still represents a huge span of kinetic energy, but it is much easier to design a compromise rotor and alternator for that distribution than for the 4-40kt range of apparent wind speeds you will observe. Pitchable blades are sweet, but they add tons of complexity & cost. Fixed blades & predictable flow rates are a good pairing.

* Hydrogens are easy to raise and deploy. They carry their weight low. When batts are full, they can be allowed to freewheel w/out overspeed noise or the risk of throwing blades. They are water-cooled, water being a much better conductor of heat than air.

Downsides are they always add drag in a negative direction, they are immersed in water, and they are prone to strike damage. Or shark damage, possibly. Also, more junk on the transom.

I'd be curious about the feasibility of a hydro-gen being faired into a keel or rudder assembly. Sort of an end-plate/bulb design, with propeller. It'd be prone to damage in groundings, and there'd be fouling issues. Huh. Be nice to get it down deep, tho. Down in the clean, heavy water.

Thank you for the explanations! Definitely aided my understanding.

On your last idea, I saw something once -- I think it was for an autonomous small aircraft intended for long term operation over the ocean, using solar power and exploiting wind speed differences according to height over the ocean, swooping back and forth as the albatrosses do -- where significant though not large energy was recovered from the wingtip vortices, apparently at very little cost to drag. It had me wondering whether a bulbtip mounted hydrogenerator might likewise be able to pick up some energy almost for free.

EDIT: Found this now, claiming actual drag reduction. http://innopedia.wik...energy-recovery

And on the above autonomous small aircraft: http://www.rcgroups....d.php?t=1253152

[soma]

For a hydrogen I wonder if a Melges 32 style outboard well wouldn't be the way to go. I'm not a fan of dangly bits. Hydro or wind. I'm also pondering a telescoping wind gen. something that can hide below decks but deploys in one step. There's lotsa empty volume on a cat.

We have 1.6kw of solar, which is great, but between shade from the stack pack and limited operating time, it's not the home run it should be.

I remember reading that for most homes the ceiling fan is the single biggest consumer of electricity. Its draw isnt biggest, but it runs the longest. A fridge compressor runs 15 minutes an hour. An Xbox/computer/dvr is only "on" a few hours a day, but a stupid ceiling fan is spinning 24 hrs a day. That's why wind is attractive. Under way, at anchor, night, day. 24/7 in the tropics normally.