SilentWind Gens Spec Update

[Mike OReilly]

Originally Posted by Delfin

It does, thank you. Just to be clear though, on those overcast days when solar isn't putting out much, are you saying to might get 100 Ah? That would be material for me....

If it’s blowin’ a gale, then yes. But no, not usually.

But with the wind gen running throughout the bad solar days, and nights of course, it takes the edge off the battery drawdown. Looking at this past season, the four times I had to pull out the gas generator coincided with the rare times we had heavy overcast AND no wind.

Have you looked at the Silentwind website? When I last looked they provided a power curve vs wind speed which seemed fairly accurate. It’s very much an exponential output curve, so at 12 knots I’m seeing about a 1/2-1 amp. By around 16 knots we’re making 3-4 amps. By 20 knots it’s up to around 8-9 amps. By 25 knots we’re up over 15 amps. I’ve seen sustained 25 amps coming off the wing gen in gale winds.

[Delfin]

Originally Posted by Mike OReilly

If it’s blowin’ a gale, then yes. But no, not usually.

But with the wind gen running throughout the bad solar days, and nights of course, it takes the edge off the battery drawdown. Looking at this past season, the four times I had to pull out the gas generator coincided with the rare times we had heavy overcast AND no wind.

Have you looked at the Silentwind website? When I last looked they provided a power curve vs wind speed which seemed fairly accurate. It’s very much an exponential output curve, so at 12 knots I’m seeing about a 1/2-1 amp. By around 16 knots we’re making 3-4 amps. By 20 knots it’s up to around 8-9 amps. By 25 knots we’re up over 15 amps. I’ve seen sustained 25 amps coming off the wing gen in gale winds.

Merci!

[Erik de Jong]

I also have a silentwind (bought in 2014) on "Bagheera", no solar as I'm too far north to make that effective.
I have no diesel generator onboard and have a 400Ah@24V battery bank.
When there is enough wind to sail, the wind generator can keep up with all my demands for underway. (Radar, Autopilot, Lights, nav instuments and computer). With the only exception of downwind, then the appearant wind is not strong enough, the moves, but the generator has not started up yet. Only with more than 16-18 knots of true wind will the generator do anything useful on a downwind course.

Bagheera is 52' and is used for charter / research projects in the High latitudes.

[George DuBose]

INHO, SilentWind generators are a poorman's version of the SuperWind 350. Just looking at a SilentWind one can see the abundance of plastic.

My SuperWind is the single most maintenance item on my boat. 10 years and I have had zero issues, other than once a crew stuck a wooden oar into the blades and broke one.

SuperWind shipped a new blade set out and I had it in two days after the incident.

Buy cheap tools and you buy them twice...

[Mike OReilly]

Originally Posted by George DuBose

INHO, SilentWind generators are a poorman's version of the SuperWind 350. Just looking at a SilentWind one can see the abundance of plastic.

My SuperWind is the single most maintenance item on my boat. 10 years and I have had zero issues, other than once a crew stuck a wooden oar into the blades and broke one.

SuperWind shipped a new blade set out and I had it in two days after the incident.

Buy cheap tools and you buy them twice...

Seven years with my Silentwind … zero maintenance.

[Erik de Jong]

Originally Posted by George DuBose

INHO, SilentWind generators are a poorman's version of the SuperWind 350. Just looking at a SilentWind one can see the abundance of plastic.

My SuperWind is the single most maintenance item on my boat. 10 years and I have had zero issues, other than once a crew stuck a wooden oar into the blades and broke one.

SuperWind shipped a new blade set out and I had it in two days after the incident.

Buy cheap tools and you buy them twice...

Absolutely no maintenance here either (has only been 4 years, but they have been tough years with a lot of icing up), I'm not sure what you refer to as an "Abundance of plastic". Except the blades there is no plastic on the thing what so ever. And the Superwind has plastic blades too. The silent wind is actually a lot stiller than the Super wind, my neighbor had one and I could easily hear that one over mine.

[rgleason]

I was wondering why you don't just heat you domestic hot water when you have extra power. It is a pretty good place to dump extra power and wouldn't the resistanxe coil accept whatever voltage/amps you can produce?

[Fluenta]

Originally Posted by Erik de Jong

Absolutely no maintenance here either (has only been 4 years, but they have been tough years with a lot of icing up), I'm not sure what you refer to as an "Abundance of plastic". Except the blades there is no plastic on the thing what so ever. And the Superwind has plastic blades too. The silent wind is actually a lot stiller than the Super wind, my neighbor had one and I could easily hear that one over mine.

To be fair to the Silentwind, the blades are actually carbon fibre. Having just taken mine apart for maintenance I can tell you the only plastic is the brush holder, the nose cone and a small terminal block. The modern ones do not even have the terminal block but rather a PCB.



We have had ours for about seven years and about 38,000 nm. No icing (!) as almost all in the tropics. Lots of miles though with the wind forward of the beam and times anchored in good kitesurf spots (therefore good wind generator conditions). We have really liked our Silentwind as it is indeed quite silent and delivers considerable power. On windward passages it covers most of our electrical requirements despite an electronic autopilot, an antique but huge fridge/freezer and a family of five onboard.


At the five year point we replaced the bearings which is fair enough considering the load it has taken. Other than that it has behaved well until a few weeks ago as we approached Majuro in the Marshall Islands it went nuts overspeeding. The latest plan is to replace the charge controller and fix the melted wiring plus perhaps some preventive maintenance as time allows. We received a shipment of parts from E-Marine so hopefully this adventure in maintenance in exotic locations goes well as we are already missing our steady stream of power to keep the boat and our family powered up. Updates to follow.


For Bagheera, thanks for your excellent website and articles. Although I had read one your articles in Ocean Navigator in the past, I found your website again this time when researching Prince William Sound. Our intention is to sail north from the Marshalls towards Dutch Harbour in June. Perhaps our paths will cross as you head off to some adventurous location and we head around Alaska towards BC.



Cheers,


Max

[CptCrunchie]

Originally Posted by Neptune's Gear

Update;
SilentWind gens now come with a new controller, the Hybrid 1000. It ups the max power of the Solar Panel connection to 550w or 40a. Also updated is the startup speed, further reduced to under 5 knots!

Remember that the controller for these units incorporates an ammeter and voltmeter, individually readable for Solar and Wind generation, and a circuit breaker is provided. These are extras on other brands..

These are the best Wind Gens available IMO, High power output, low noise, low startup speed, and include a regulator for your solar panels.

If you would, could you respond to this article?

Can not recommend Spreco Silentwind Wind Generator - S/V Gudrun V

[Erik de Jong]

Originally Posted by CptCrunchie

If you would, could you respond to this article?

Can not recommend Spreco Silentwind Wind Generator - S/V Gudrun V

It seems like the person who wrote this article had some bad luck with the controller. Not sure what is going on there, maybe an issue on the boats electrical system? We have been running the silent wind since the spring 2015 on Bagheera and two of them on Snow Dragon II since 2014 and have had no issues. We have several bluewater cruising friends that run silent winds as well and none of them had issues either. We once lost a couple of nose cones due to our own fault. When we mentioned that on a boatshow to one of the representatives of Silent Wind, we had a couple of new ones in the mail within a week free of charge.

I seriously can't complain about the silent wind. It is truly the most silent wind generator I have ever encountered and the efficiency seems to be higher than all other wind generators judiging by what I hear form other cruisers.

[Cpt Pat]

Originally Posted by Mike OReilly

My view is that you should maximize your solar first. Only after that, if you still have need for more amps, I would consider a wind gen. But sometimes the wind gen really makes a huge difference. I’m happy we have both.

Great posts, Mike. Thanks. I agree one should first maximize solar. I've managed to set up 400 watts of solar on my little Ariel (26 feet) with a combination of deck-mounted panels and two 65 watt panels hung between the lower shrouds. Don't laugh - they produce the majority of my power even though they aren't horizontal. Plus, since they're rigid conventional panels, they're far cheaper per watt. They do need bracing since they ordinarily depend on being mounted to a rigid support surface. Cross braces made from flat aluminum stock has worked fine for the eight years I've had them "up". (They've gone through gales.) Since they hang right over the CLR, they have minimal effect on yaw stability.

My second source of power is a towed impeller generator. Yes, it causes drag (so does a wind turbine when sailing upwind) but the drag is directly aft resulting in no degradation to yaw stability. Once I'm up to hull speed, the bow wave is the limiting factor on speed. And the dynamic range of speeds is limited between zero and a little over hull speed, removing the need to provide for over-speed protections. Naturally, it only works while underway, but at my hull speed, it produces 8 amps (@ 13 volts) day and night. 100 honest watts. The efficiency of the towed impeller generator increased substantially when I replaced my lead/acid batteries for LFE batts, which don't waste power with a low current absorption phase. The LFEs will soak up every available watt, and don't degrade with a partial state of charge.

My last choice would be a wind turbine. The aerodynamic drag forces are far from the CLR (usually at an aft extreme) so they degrade yaw stability. The outputs are often disappointing: the worst dollar-per-watt ratio (besides an engine-driven alternator -- which I don't have). And there's the added windage, noise, vibration, maintenance, and concerns for gale survival to contend with. I just don't like the idea of having a wind driven decapitator swinging around over my head - just waiting to throw off a blade to impale me in a gale... moments before it dynamically disassembles itself from the missing-blade imbalance.

[Cpt Pat]

P.S. I forgot to mention that the long mounting tube holding up a wind turbine acts as a lever-arm to increase the angle of heel. It's as if someone tasked an engineer with devising a contraption will self-destruct in any heel angle near 90 degrees, and that will intentionally destabilize a boat while incorporating life-safety hazards and factors contributing to general annoyance.


Errata on above post. I brain-faded when I typed "LFE". I meant
"LFP" -- LiFePO4, i.e., lithium ferric phosphate batteries.

[Mike OReilly]

That’s an impressive amount of solar watts on such a small boat Pat. I have 400 watts myself, but mine is a 37-footer.

And interesting comments regarding the use of a tow generator. I’ve never used one — heck, I don’t think I’ve known any boat to use one. My impression is they were more used in the past, but that may be a false perspective. In any case, a thread comparing the relative usefulness and challenges of solar vs wind vs water generators might be an interesting one.

You’re the first to raise the issue of shifting CLR and and aerodynamic drag. I’m sure that’s true, although on my 15 ton vessel I really doubt it has a substantial, or even measurable effect. I have not noticed the difference when sailing with, or without, the windmill in place. But I can see it having an impact on a smaller, lighter craft.

Interesting you should mention gale survivability. I sat at anchor through a three-day Newfoundland gale last season. Sustained winds into the 40s. My windmill (a Silentwind) came through just fine. It has performed equally fine in shorter periods of 50+ winds. If I was prepping for a hurricane I’d take it down, but for what I’d call normal cruising weather, it seems fine.

BTW, I still say solar is best, and generally the most preferred passive charging system. But most monohulls will have a hard time finding enough panel real estate. This is where wind, and perhaps water generators can fill in the gap.

[Discovery 15797]

Good discussion and perspective.

Hydrogenerators have been around for awhile, and like wind generators they are becoming more efficient. As Cpt Pat said the output / dollar is great, but the initial cost is quite high. The Watt & Sea generators start at about $4K, while the one for a 40' boat is >$5K. Another drawback is that they are only really viable underway (they need at least 1.1 to 2 knots of water speed before start up). When you consider 'at sea days' vs. 'at anchor days' the hydro generator cost becomes even less appealing.

Yaw rotation on a sailboat is more affected by things sticking down into the water than by things sticking into the air. This becomes quite noticeable with wind vane rudders in the water.

IMHO, the added windage is no more (perhaps even less) than a radar antenna mounted on the mast and vibrations can be minimized when properly installed, and the noise of my SilentWind is less than the clanging of the halyards of the boats in the marina, and certainly less than the wind generators of the past. There have been many improvements to wind generators over the past several years. Although as Mike indicated...these annoyances may be more pronounced on smaller and lighter vessels.

Based on at sea vs at anchor days, I choose to go with 600 watts of solar and a Silent Wind. The solar generates the majority of my demand, but on cloudy days with a 10 knot breeze the Silent Wind keeps the batteries topped off.

[DeepFrz]

Randall Reeves (Figure 8 Voyage, Blog – The Figure 8 Voyage) has commented a lot on his hydro generator getting fouled with Sargassum Weed. As the sea has been warming the Sargassum has increased and spread, especially in the Atlantic. He has a Watt and Sea generator.