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I am in the upcoming Golden Globe Race. I'm looking to add a hydro generator to my solar power. Anyone have experience this manufacturer or any other brands. Reliability is paramount! Looking for real life experiences, including failures.

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I have zero experience with these, but do they work well at the displacement speeds that Golden Globe Race boats sail at? 

production-curve-cruising-300-gb.jpg

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I think there are different versions for that work for different boat speeds. They seem to have a good amount of spare parts available if repairs are needed. Watt & Sea was founded by VG winner Yannick Bestaven so there’s some pedigree behind the product. They have just brought out a wind generator as well

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1 hour ago, Alex W said:

I have zero experience with these, but do they work well at the displacement speeds that Golden Globe Race boats sail at? 

production-curve-cruising-300-gb.jpg

The Golden Globe boats actually sail?  Is that with or without their kelp reef?

I thought they were just shoved along by the wind and current.  

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I was wondering just how long it would take a S/A dick to show up...

If I can plan on sailing the Southern Ocean and looking up at the seas... I can ignore you!

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We have sailed offshore with one for the last four years,  I have lots of comments. Maybe PM me?

IMG_1292 small.JPG

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Posted (edited)
7 minutes ago, Fiji Bitter said:

Why not share it with all of us?

 

Because I am wordy, probably boring, and SA (often) is a somewhat hostile environment where a few folks seem to engage in the equivalent of just plain trolling?

I think they are in general... an essential piece of gear aboard or boat and the manufacturer has provided very essential and very good product support for us. 

Even though we have 600 watts of PV... We still really need the Watt&Sea on passages.

Edited by 2flit
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Just now, 2flit said:

Because I am wordy, probably boring, and SA (often) is a somewhat hostile environment where a few folks seem to engage in the equivalent of just plain trolling?

Nah--easy to filter the trolls. Many of us would like to hear your perspective and can work our way through wordy posts.

Was the W&S eventually worth the hassle?

 

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2 minutes ago, stief said:

Nah--easy to filter the trolls. Many of us would like to hear your perspective and can work our way through wordy posts.

Was the W&S eventually worth the hassle?

 

YES!~

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Just now, 2flit said:

YES!~

Were there speed limits? Imagine you looked at other boats those 4 years. See anything that made you wonder about the W&S?

(am tempted by electric drives that can charge batteries under way, and get rid of an outboard--but understand cruising speeds are too low)

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11 hours ago, 2flit said:

Because I am wordy, probably boring, and SA (often) is a somewhat hostile environment where a few folks seem to engage in the equivalent of just plain trolling?

Interesting to know your take on their regulator?

Have heard some people make it a mandatory spare. That was a fair while ago though.

Ditto @stiefon the trolls

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On 5/6/2021 at 3:26 PM, stief said:

(am tempted by electric drives that can charge batteries under way, and get rid of an outboard--but understand cruising speeds are too low)

I was thinking the same - ditch the dinghy motor in favor of the unit described by The Sailing Frenchman in the video. He measures its efficiency at 10% (10nm of sailing to charge the motor to go for 1nm). This sounds bad, but it's a round-trip, so charging-only is probably 55% (half-way). How does that compare to W&S?

 

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We just received our new Watt$Sea 2-blade 240mm prop to "Beta Test"  for them.  

It6 is a radical departure from all the previous designs that we have tried.

It has a partially serrated (about 3mm deep serrations) on the trailing edge. A semi-vortex tip/blade end, and a radical twist with a progressively curved twist.... a total departure from anything we have seen before.  AND>>> the hub has replaceable blades!!!!

YEA!!!!

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A 240mm seems more appropriate than their normal size.

I am amazed that the diameter of the normal propellor is so small. I would love to see repeatable experimental data that led to the tiny propellor.

In wind farms and water current turbines, size really, REALLY matters.

The non-dimensional power coefficient for a propellor is Cp = HP/(fluid density * RPM^3 * diameter^5). So energy generated by a hydro generator is related to the FIFTH POWER of the diameter, and only the third power (still a lot!!) of RPM. Hence, a much larger prop can spin much slower and generate far more energy. As we see with wind farms.

There are always trade-offs in engineering. A faster spinning motor can be smaller, so a smaller hub, so less parasitic drag. Putting the motor in the hub is simple, and provides good cooling due to water flowing past the hub. A generator is of course exactly a motor.  Perhaps this was their driving principle.

Still, it seems a small hub yet a larger motor would simply require a 90 degree transmission of some kind, like a 90 degree gear on a sail drive or small outboard, or a toothed belt because the HP is low (3kw is 4hp). While a little complexity and loss, it sure won't compare to the 5th power improvement in energy.

I am about to try a Brunton AutoProp to regenerate using my inboard electric motor. The ElectricYacht motor controller does support re-generation.

My prop is about 480mm diameter, so twice the diameter as this new larger 240mm diameter prop. Pitch is automatically adjusted by the AutoProp, and pitch directly effects RPM at any given speed. But let's assume the auto prop does what it does and automatically adjusts pitch for best L/D. And let's assume that W&S also sets pitch to best L/D, as they probably do if they actually engineer their stuff.  If pitch is about the same as on the W&S, then RPM will be about the same. Therefore, I should be able to generate 2^5 or 32 times as much power, if the system is 100% limited by propellor (which of course is not the case) and RPM stays the same (which it will not).

Well, like I said, there are trade offs, and perhaps W&S went to higher RPM than best L/D for the prop, to get more power from the small diameter motor. If W&S went with, say, double the RPM that would provide optimal L/D on the blades to increase drag from the prop while reducing drag from the hub, then my improvement will be less: 2^5 / 2^3 or only 4 times as much power generation, but running at better L/D so less drag from the prop (more from the hub).

I currently have a folding prop, which of course cannot generate any useful energy through re-generation, even if some people claim it can be done. A folding prop is limited in regeneration to the amount of power required to overcome the inertia of the spinning blades, which is very little. As soon as even a watt or two is pulled from the spinning folding prop, it folds, instantly. I can be sailing at 9 knots, prop open and spinning at about 2k RPMs, and as soon as any regeneration is enabled, the prop instantly folds.

 

 

 

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I'll mention here that the blades on the standard 240mm fixed prop from Watt&Sea have always (eventually) snapped off at their root (at the blade hub). That prop will lose its blades on any AWS boat. I guarantee this and it is not from fish bites or dunnage/flotsam hitting the prop. Any boat that can accelerate quickly and routinely see >12-13 knots on any given day will break the 240 mm prop. And - unfortunately - the 200mm prop (we have three of those now, one with manually variable pitch to 22kn boat speed) just does not make any power at <8kn, and hardly any at 10kn.

The 2-blade (instead of 3) may help with this, or it may not, but having replaceable blades is a big step forward... If they are at least as strong at the connection of the blade to the hub; and I have some questions about that strength on the Beta prop.  

I also have to say that the design on the blades is highly evolved and production plastic moulds of this nature can be expensive to have made, W/S seems tight-ish on funds, and I think this is going to be a commercially released prop soon. It sure looks way more sexy than the old POS that they have been cranking out.

It's winter here and we sail for Whangarei next month so will have a chance in the open ocean on an overnighter to try this thing out.

For $1000's of dollars more they do produce a hydraulically controlled aluminum prop and generator assembly that was adjustable from the deck (instead of raising it, using the prop puller, and switching out props)

Oh.. and there is no 'normal' sized prop for a Watt&Sea. They have traditionally made three prop diameters, each for different boat speed ranges. The 240mm is the mid-sized diameter that they sell.

 

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22 hours ago, carcrash said:

As soon as even a watt or two is pulled from the spinning folding prop, it folds, instantly. I can be sailing at 9 knots, prop open and spinning at about 2k RPMs, and as soon as any regeneration is enabled, the prop instantly folds.

That 'hand break' that folds the prop at only that watt or two or a fraction of an amp a good translation to how much load your engine alternator produces on engine and belt.

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I have 17,000 miles with a cruising 600 long with adjustable pitch prop. Concur they are necessary down in the Southern Ocean. Not much sun down there in Summer. Only other natural way to generate power is with a wind generator. A must to have multiple methods to generate power as problems will come up.

It is fussy, but once you learn how to speak Watt & Sea you get along with it. Make sure you mount it so that you can get at the hub easily when it's up. You will be replacing hubs, blades, pitch, tightening bolts, etc. too often. I did carry a spare controller but didn't need it. It vibrates when the prop gets out of balance or when the mounting bolts are loose, so you'll be leaning over the transom from time to time. I did end up hitting something which bent the pin so far the unit pulled out of the gudgeon and was dragging behind the boat, held on only by the lifting tackle (a must). Also get the ridiculously heavy mount they sell and use loctite on the bolts. Yes, I bent that too.

Hope this helps.

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Custom mounting hardware is a very good way to go, The watt&sea mounts can be weaker than required and the pivot bolt (if they have not increased the diameter since I last looked)  is undersized for the forces involved. It's hard to appreciate the forces that develop on these things when reaching at 16 knots or more.

Ditto Ron Swanson's comment on 'You MUST be able to easily reach the hub and prop when the unit is raised'

Here is a picture of our mount. We increased the hinge pin diameter from metric 6mm to 8mm and this has not bent. It also helps to retain the unit with the stainless pivot pin/bolt tabs that you see at both the top and the bottom of each of the W&S pivot points (Upper and Lower). This is not the case the last time I looked at the W&S mounts.

detail tiller watt Sea.jpg

full side.jpg

TopView.jpg

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12 hours ago, Ron Swanson said:

Make sure you mount it so that you can get at the hub easily when it's up.

Incorporating a mount that facilitates easy removal of the entire unit at sea sounds like it is worth the effort?

Any regulator problems, heard early on there was?

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^^^^^ sorry posted this before seeing this and could have joined the two of you same question.

12 hours ago, 2flit said:

Ditto Ron Swanson's comment on 'You MUST be able to easily reach the hub and prop when the unit is raised'

 

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On 5/22/2021 at 6:36 AM, jack_sparrow said:

Any regulator problems, heard early on there was?

No worries. No controller problems, feeding LiFePO4. One odd thing was when ordering the spare controller, they needed the serial number off the generator unit. Model number was insufficient. There must have evolved things. Default programming setup for lead. Lousy programming interface via mini usb serial connection. They really need to bluetooth them.

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24 minutes ago, Ron Swanson said:

No worries. No controller problems

Thanks Ron. It was over a decade ago sounds as though it was a short lived & quickly sorted. 

To be expected with the Yannick's attention to detail.

 

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