Wind Generator on Monohull Bow ?

[JonathanSail]

Hello Cruisers,

I've gone back and forth over possible mounting locations for a wind generator on my 28 foot monohull. The solar panels on the stern are a higher priority but I'd still like install a wind generator if I can find a place that won't cause too many problems with panel shading, or other systems on the boat.

One installation setup that I've been considering is to set the wind generator up to minimize the hassle/time to erect it and then to set it up on the bow for times when I need the power and will be at a windy anchorage for a while. The boat would still be moveable/sailable with the genny up but most of the time the genny would be down and stowed below.

I've already got the wind generator and the poles/etc. and have found places to store the genny/blades/poles so storage when not erected is not an issue. I also am familiar with the inconvenience that will be involved in raising/lowering the genny but for occassional use when the genny will be up for a week or more I think raising and lowering the genny if needed may be worth it.

I'm not planning to use the boat on long passages where the genny would come in handy for underway power but I guess sailing with the genny up isn't out of the question. Also, I plan to have enough solar to meet my daily needs power wise under normal conditions but since l need to do computer work every day I want to make sure that I have enough power for the laptop even when it's been cloudy and overcast for a week or two. Running the engine from time to time is an option, as is getting a small honda/yamaha generator.

My question is, why don't folks install wind generators on the bows of monohulls? Is it because of problems they would cause while underway, at anchor or both? Mounting one on the bow seems like it would offer some nice benefits including getting the noise away from the cockpit, putting the genny in undisturbed wind and, most importantly, the solar panels on the stern wouldn't be shaded out. Let me know what I'm missing in my thoughts on this.

Thanks,

Jonathan

[sailorchic34]

I can imagine a loose jib sheet shredding the blades or the blades shredding a spinnaker. To much flapping going on at the bow I think.

[sww914]

On my trimaran I hung mine from a spare halyard at the top of the mast out to a cleat on the back of an ama. The width allowed me to keep it far enough away from the leech of the main and away from the backstay. I realize that you don't have that luxury of width but maybe if you tie from the top of the mast to a corner of your stern rail you can get away with it.

[markpierce]

All the wind generators I've seen on sailboats have been in the area of the stern. Little doubt there is a good reason for this.

[David_Old_Jersey]

I like a bit of "Blue sky" thinking

Apart from I think sailing (using a foresail) would be pushing yer luck, I don't see why not (if you can live with the dismountable PITA angle / storage - on that note, no reason why it could not be stored complete on the stern (maybe for use underway? - where shading the solar might not be such an issue?). Options is always good

My only caveat would be not to restrict access to the Anchor etc, just in case you drag at 3am

If you go for the bow - let us know how it works out

[Vasco]

Windbugger used to make a "portable" wind generator which most folks used to hang in the foretriangle. Also I know of a trawler that mounts a KISS on the bow when at anchor.

[smj]

Windbugger used to make a poleless version that would attach between the jib or spinnaker halyard and a foredeck cleat. Seems it would be a lot less hassle to remove than a version with a pole.

[Blue Stocking]

Saw a boat with a simple stainless A-frame pivoting on 2 foredeck stanchions with gen mounted. Raised A-frame with spin h/yard while in port.

[bene505]

If you have a boat that tacks at anchor, like our Beneteau 50, you will NOT want any more windage up front. It will make the tacking even more pronounced.

Our Fourwinds-ii wind generator on the stern actually prevents all but the slightest tacking -- and we previously tacked through 90 degrees on windy nights. Yes, 90 degrees.

(On a 30-knot-wind night we had a Hanse 49 rafted-up on one side and a 30' sailboat on the other side, and we still tacked an anchor all night. I didn't sleep much that night. BTW, in the morning I dove on our CQR and saw that it made a bit of a plowed furrow and dug in so the shaft was 3" below the sandy soil.)

So I'd check to make sure you won't cause your boat to tack at anchor.

Regards,
Brad

[Blue Stocking]

The tacking is a good point to make.
Brad, do you lock your helm over about 15 degrees.
Thats how I stop mine from sailing about. Seems to heave-to on one tack, and round up on the other.

[witzgall]

Wind generators can be very dangerous devices. Imagine that you are forced to be on the bow of your boat to deal with a dragging anchor. Now add a huge swell, making the bow movement up and down very pronounced. Would you want that spinning hatchet blade anywhere near your head at this time?

Chris

[bene505]

Note that you don't have to worry about shading the aft solar panels when the sun isn't shining.

I cut our pole from a 20' long 1.5" schedule 40 (actual Outside Diameter 1.660") pipe. It attaches on the transom, inside the sugar scoop. I left it 18 inches to long, figuring I cold always cut it later. After using it, I'm very glad the extra 18 inches are there. To get to the blades, I stand on the pushpit and have the pole to hang onto. To work on the genny (attaching the speed brake, balancing, or removing the unit) I stand on the davits, again holding onto the pole and the lateral supports. It works great.

Originally Posted by Blue Stocking

The tacking is a good point to make.
Brad, do you lock your helm over about 15 degrees.
Thats how I stop mine from sailing about. Seems to heave-to on one tack, and round up on the other.

I've tried lashing the helm, but not at any predetermined rudder angle. I ought to try more specific angles. Note that I have lots of room and so use a lot of scope. I routinely have 90 feet out in 10 feet of water. I also use 2 anchors, which helps at certain wind angles.

Regards,
Brad

[JonathanSail]

Thanks for the good feedback.

It sounds like interference with loose headsails is the biggest risk with the setup that I have had in mind, followed closely by increased sailing on anchor.

I have in mind mounting the genny on a tall enough pole that gets it up and out of the way so that it wouldn't be too dangerous when working the ground tackle, etc. This also gets the genny forward of the headstay but the risk of shredding a sail/destroying the blades is real. Sailing at anchor could probably be balanced with a riding sail/rudder tuning but more overall windage is not exactly a good thing in terms of holding.

Another idea would be to put the wind generator on the masthead. I've never seen this on a monohull either but have seen it on the aft masts of ketches. It would make maintenance a hassle and could be a problem in severe weather but seems like it would offer some benefits. Any thoughts on a masthead mount?

Thanks,

Jonathan

[bene505]

Jonathan,

Regarding masthead mounting, there are 2 issues, windage and vibration. (You already spotted maintenance.)

On land, vibration is the reason you don't see them on top of houses, but on a separate tower near a house. Not sure I'd want a vibrating thing "up there". I still haven't fully balanced our Fourwinds-ii, and I've shut it off in the middle of the night to help get some sleep. (There's one particular rotation speed which vibrates the most, probably a resonant frequency with the 12.5 foot tower it's on.) On top of the mast it might stress the rigging too, not sure about that one.

Windage would be the other reason. It's windage in the wrong spot and would affect sailing performance, comfort, and perhaps even storm survivability.

Keep thinking, these are the same thoughts that people go through when they get a wind generator.

One more thing. When I was planning more-solar versus wind, I looked at the average wind speeds for the area where we anchor. Now "living it", I'm finding that when the weather people say "average wind" for a given month, I think they mean "the average of the daily peak winds during that month". 70% of the time there isn't enough breeze to get the wind generator up to the 13 volts (plus a fraction more voltage to overcome the loss in the diode) needed to start charging.

For instance, take a look at this useful site:
Weather History

After that page comes up, substitute the 3-letter identifier for your nearest airport, right after the "K". Also substitute the date you are looking for. The above example is for Montauk (MTP) on July 31st, 2011. That's why the address has "KMTP/2011/7/31/" in it.

In that chart you'll see the average wind speed is 5 knots or lower, on 22 out of 31 days. But, if you look at data published on other sites, you'll get a completely different conclusion. Look at the July data point/range on this graph from city-data.com:



The real average is nowhere near 8.75 mph.

By the way, I love the fact that every once in a while, we get wind enough to top off our batteries. However, if I had to do it over, I'd get a 215 Watt solar panel and put it on top of our dinghy davits, or a Honda 2000 generator. Either way I'd be ahead on money (for just the mountings and fittings!) and way ahead on the many hours making a storm-worthy mounting system for the wind generator. Plus there'd be less vibration and no dump loads needed.

Finally, every post regarding wind generators needs to include this seemingly extreme statement: "Do not get an AIR-X or other noisy wind generator and if you do, stay the hell away from me." The smaller wind generators can sound like a Cessna 152 taking off. Perhaps it's the way the blades are designed to spill air in strong winds. Regardless, it's not something you want to subject yourself or others to.

Regards,
Brad