Hydrogenerator for power

[Wckoek]

I am looking for a solution to generate power other than solar to save deck space, had anyone had any experience with these hydrogenerators?

Cruising hydro generator

[GordMay]

Greetings and welcome aboard the CF, Wckoek.

[UNCIVILIZED]

Welcome to CF!

You might do some reading here http://www.cruisersforum.com/forums/...e-33857-2.html

[barnakiel]

WattSea. Seen a dozen but never fitted one myself.

Early models had bracket issues. Now believed to be sorted out.

Used by racers and by many cruisers as well.

The models vary - different screw for different boat speeds. You do want to travel faster rather than slower - similar to wind speed for wind gens. No good in a slow boat.

Cheers,
b.

[Stumble]

Hydro gens work very well, but you need a high average speed to make much power. So it is really boat dependent. Some boats can make more power than they would every use, others struggle to make enough to justify them.

[Jim Cate]

Originally Posted by Stumble

Hydro gens work very well, but you need a high average speed to make much power. So it is really boat dependent. Some boats can make more power than they would every use, others struggle to make enough to justify them.

Depends on what you mean by "high speed". We had a home brew trolling generator on our previous boat, and it produced 10 A at 6 knots through the water. Went up steeply above that speed, but the prop would jump out of the water so frequently that it became useless.

If you know that you will be sailing at lower speeds, you compensate by using a larger prop of appropriate pitch... even at say 4 knots, there is a large amount of energy available. The harder thing is to design a system that works well over a wide speed range... I sure was not successful!

Jim

[GILow]

Originally Posted by Jim Cate

Depends on what you mean by "high speed"....

....

If you know that you will be sailing at lower speeds, you compensate by using a larger prop of appropriate pitch... even at say 4 knots, there is a large amount of energy available. The harder thing is to design a system that works well over a wide speed range... I sure was not successful!



Jim

A towed generator is on my list of things to build. I figured the simplest solution to wide range of speeds problem would be a number of different propellers that could be easily swapped in depending on forecast conditions. Am I dreamin'?


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[Matt Johnson]

Seems that there are a lot of functional, but noisy, used wind generators available for cheap on craigslist. Should be a good base to start with.


We're converting an Ampair 100 wind gen I have lying around to towing. Any suggestions on pitch and size to start with?

Matt

[Jim Cate]

Originally Posted by GILow

A towed generator is on my list of things to build. I figured the simplest solution to wide range of speeds problem would be a number of different propellers that could be easily swapped in depending on forecast conditions. Am I dreamin'?


Sent from my iPhone using Cruisers Sailing Forum

Originally Posted by funjohnson

Seems that there are a lot of functional, but noisy, used wind generators available for cheap on craigslist. Should be a good base to start with.


We're converting an Ampair 100 wind gen I have lying around to towing. Any suggestions on pitch and size to start with?

Matt

For both Matts,

What I used turned out to be a second-hand 6HP outboard prop. I got it for free from a prop shop, as it was too badly dinged to be repairable for propulsion use. So, that sort of price means that one can do some experimentation for little investment. My generator was a 32 volt permanent magnet ex-tape drive motor, which were available then very cheap from surplus houses. I think that using a wind generator unit would work ok, but I dunno how fast they need to turn to produce useful power. PErhaps the OEM could tell you that, and you could then work out the necessary pitch to get the proper rpm at your design cruising speed... all kinda ad hoc, but should get you into the right ball park.

Jim

[GILow]

Originally Posted by Jim Cate

For both Matts,

What I used turned out to be a second-hand 6HP outboard prop. I got it for free from a prop shop, as it was too badly dinged to be repairable for propulsion use. So, that sort of price means that one can do some experimentation for little investment. My generator was a 32 volt permanent magnet ex-tape drive motor, which were available then very cheap from surplus houses. I think that using a wind generator unit would work ok, but I dunno how fast they need to turn to produce useful power. PErhaps the OEM could tell you that, and you could then work out the necessary pitch to get the proper rpm at your design cruising speed... all kinda ad hoc, but should get you into the right ball park.

Jim

Jim, those tape drive motors are becoming pretty scarce now, but as a metric they interest me because there is a bit of data around on their voltage characteristics against RPM. From what I read they needed at least 350 rpm to start charging a nominal 12 volt system. This interests me, because it suggests you were getting at least those sorts of shaft speeds from the 6hp outboard prop, more than I would have expected.

Also, the surface area of a 6hp outboard prop is a lot smaller than I anticipated needing for this job, I had not really come up with a credible number but I was planning to start at around the 15 hp range. Perhaps not. Thankfully I have a number of props in the garage I can pinch from various outboards I own, so the plan was to try them out, get the size right, then pop down to the local outboard wrecker for chosen size(es)

These guys have the sort of thing I would use for the generator when the time comes, very low rpm, plenty of power capacity.

Permanent Magnet Alternator Wind Blue Low Wind

Not cheap, but not too bad either.

Matt

[Jim Cate]

Matt, another approach might be to do one of the conversions of a Fisher-Pykel washing machine motor. There are several sets of instructions on the www for converting one of these to a low speed alternator. Supposedly very efficient, but no personal knowledge.

Your plan of trying all the props that live in your shed sounds good to this pragmatist! There may be an issue with shaft size. IIRC the 6 hp was 9/16 inch. I didn't bother with splines, just locked the prop between a collar and a nut, tightened down hard. Never seemed to slip... I guess the torque ain't so much!

Jim

PS Give some thought to how you will keep the prop down in the water at higher speeds. I never came up with a good plan, but a friend made a clever hydrofoil on a good bearing that hung from the fwd end of the prop shaft. He claimed that it worked well, bt he also smoked a lot of dope! Hmm... thinking back, he was using some old 1x19 rigging wire instead of rope to transmit the torque to the genny. that too might be worth thinking about.

Jim

[lifgun]

Wckoek, I use a watt and sea hydro generator cruising 600 since two years on my boat. If you are under way this thing is working just amazing great. Above 6 knots he is covering 100 % of my energy needs. After 7.5 knots I start normally producing hot water :-) . However it was a very good investment and is with every penny ! Have a look on my website - there you should find a few photos how the gen is mounted. This is in fact the only tricky thing to mount the hydro in the correct way.

[El Pinguino]

Originally Posted by Jim Cate

.......
PS Give some thought to how you will keep the prop down in the water at higher speeds. I never came up with a good plan, but a friend made a clever hydrofoil on a good bearing that hung from the fwd end of the prop shaft. He claimed that it worked well, bt he also smoked a lot of dope! Hmm... thinking back, he was using some old 1x19 rigging wire instead of rope to transmit the torque to the genny. that too might be worth thinking about.

Jim

I reduced the problem by fitting prop shaft anodes to the s/s 'log' ( that the blades are mounted on end of ) to ballast it down a bit. Other option wouuld be longer rope.

Only gets airbourne now when going a bit fastish in a biggish following sea... then it will leap out of the face of the following wave and come at you like Ahab's harpoon...

[El Pinguino]

And also..... put the zincs on the front of the 'log' to make it nose heavy.

You could also try zincs on the rope......

[Wckoek]

Originally Posted by GordMay

Greetings and welcome aboard the CF, Wckoek.

Thank you, pardon me for not introducing myself first since I couldn't think of how to introduce myself, hopefully you guy will know me more if I got to post here more, just registered after reading posts here for quite a while.

UNCIVILIZED, thank you and I've read the thread, most opinions posted there was of home made generator and I couldn't make my opinion on that, I just haven't seen hydrogenerator system personally on a cruiser but they are popular on race yachts, I just thought that they must have been efficient and reliable to be able to gain acceptance in races.

Lifgun, maybe conservatively 5 to 6 knots is about right, does the 600 produces more power than 300 in slower speed? How many watts the 600 can produce in an hour let's say 6 knots?
I imagine it wouldn't be too difficult to adjustable, of course it can't beat diesel generator but if it is worthwhile as a backup system for what it cost?