Hydrogenerator yes or no?

[Paul L]

[QUOTE=KISS;2440630]I appreciate those physical limitations, but the alternator still makes a big difference. A standard alternator produces zero power at boat speeds at which a low rpm alternator would produce something. That something, over many hours, can add up to a lot.

I wasn't trying to suggest that the commercial units could be improved upon (as I said earlier, they no doubt already use the kind of low rpm alternators I'm talking about). Rather I was suggesting that some DIYers get a bad result because they use a standard alternator.



Again, "significant power" is in the eye of the beholder.

If your energy budget is 500AH/day, 1A is trivial. If it's 50AH/day, it's another story.

Also, again, you can only put up so much solar./QUOTE]
It doesn't take a lot of solar to get 50ah a day. It takes a lot to get 250ah a day.

[Stumble]

Whoops, I messed up the formula. It should have been...

Power(in kw)=Cp * p * A * V^3 * k

P = Power output, kilowatts
Cp = Maximum power coefficient, ranging from 0.25 to 0.45, dimension less (theoretical maximum = 0.59)
p = Water density lb/ft^3
A = Rotor swept area, ft^2
V = Wind speed, mph
k = 0.000133 A constant to yield power in kilowatts

So my earlier statement of prop size was off substantially. Speed should have been takes to the third power not the second.

[KISS]

Originally Posted by Stumble

Whoops, I messed up the formula. It should have been...

Power(in kw)=Cp * p * A * V^3 * k

P = Power output, kilowatts
Cp = Maximum power coefficient, ranging from 0.25 to 0.45, dimension less (theoretical maximum = 0.59)
p = Water density lb/ft^3
A = Rotor swept area, ft^2
V = Wind speed, mph
k = 0.000133 A constant to yield power in kilowatts

So my earlier statement of prop size was off substantially. Speed should have been takes to the third power not the second.

For an 8" diameter prop, that works out to approximately:

1 kn, 0.1 A (12v)
2 kn, 1 A
3 kn, 3.4 A
4 kn, 8.1 A
5 kn, 15.8 A

That's similar to what WattnSea shows on their performance chart.

[HR42]

Whilst this one isn't as polished as the watt and sea, the mounting is resolved. The propellor is a weak point on the watt and sea so don't know about this one.


https://www.swi-tec.us/hydro-charger...r-transom.html

[Epicurean]

I'd like to second what Jim said about sails getting in the way. Also, the heel of the boat at times will make solar ineffective. Sitting at anchor solar is great, and if it's cloudy a lot of people supplement with little Honda generators. But on a passage, if it's rough, at night (or it's often cloudy when it's rough weather), and under autopilot I'm not a fan of putting a running gas generator on deck. So, if you need the amps for chart plotter, radar, refrig, and ap your only other alternative is to run the main engine. Personally, sailing with the engine on is not why I go sailing. When I've had trolling generators working it's great. Makes the trip more relaxing and enjoyable. I'd like to hear what experience people have with the Switek. And how do you attach the low speed alternator to a sail drive?

[DeepFrz]

Here is an article by a couple doing it. They love there hydro generator. Start at about 14:15.

https://www.youtube.com/watch?v=LiPq1L6e6pE

[Cotemar]

Solar is all that’s needed for electrical needs when cruising.
Its Silent, efficient, clean and maintenance free.

NO Hydro Generator or Wind Turbine is needed for any kind of cruising, including a circumnavigation.

Remember it only takes 17 to 20 days to cross any ocean and you will spend 95% of your cruising time at anchor.
.
.

[DeepFrz]

Originally Posted by Cotemar

Solar is all that’s needed for electrical needs when cruising.
Its Silent, efficient, clean and maintenance free.

NO Hydro Generator or Wind Turbine is needed for any kind of cruising, including a circumnavigation.

Remember it only takes 17 to 20 day to cross any ocean and you will spend 95% of your cruising time at anchor.
.
.

I assume that this is your experience but it is not necessarily anyone else's experience. Why not state your experience as an experience instead of pushing your views on everyone?

[Nelsonbrad]

Originally Posted by Cotemar

Solar is all that’s needed for electrical needs when cruising.
Its Silent, efficient, clean and maintenance free.

NO Hydro Generator or Wind Turbine is needed for any kind of cruising, including a circumnavigation.

Remember it only takes 17 to 20 days to cross any ocean and you will spend 95% of your cruising time at anchor.
.
.

I do agree with you, But it all depends on the amount of sailing miles you do per year that helps makes this decision.

[Paul L]

Originally Posted by HR42

Whilst this one isn't as polished as the watt and sea, the mounting is resolved. The propellor is a weak point on the watt and sea so don't know about this one.


https://www.swi-tec.us/hydro-charger...r-transom.html

I saw one of these mounted on a smaller World Arc boat the other day. It looked like cleanly mounted, non-intrusive small unit.

I still have a hard time justifying one at these prices, usd$3,700. If you do a 26,000 mile circumnavigation at an average of 6kts then you get a cost of something like $1.08 per hour or 7 cents a mile.

[SV Luckyfish]

I wouldn't cruise again without a hydrogenerator. It solves the issue of solar at night on passage meaning we can keep our storage light and still meet our electrical demands (radar, water maker, chartplotter, AIS transponder, fridge, freezer, tri-colour etc etc). Here is our performance review of a 300W Watt & Sea unit on the Wharram Tiki 38 catamaran, Luckyfish.

https://www.youtube.com/watch?v=bzmHhwUI-V4

[cajucito]

I started with solar hydro and wind in aug 2016. Left Ireland in beneteau 44cc. Now in Grenada going to do another season in caribbean then into pacific. I agree go as much solar as you can fit id say min 400-500w mount in a way that they can be always perpendicular to the sun. (A 2 inch pin at 90 degrees to the panel makes no shadow) this makes a huge difference. Hydro and wind dont do much. Pretty much nothing but trouble and a waste of space and money. My solar array is on top of the stern A frame. Make sure you can lay it flat and batten it down in high winds. Get AGM batteries and as big an electrical charger as you can find. Then a small diesel genset 3-4 kw is very efficient at charging as AGM can take a very big charging current. A big alternator isnt s bad idea either But running engine to charge batteries is very inefficiet. Buy a 1200w electrical pond pump from lidl aldi wrap seal it in 4 plastic bags to keep it all dry and throw it in the bilge with a hose long enough to reach the cockpit. It will make a great emergency pump if you are unlucky enough to get holed. If you cant empty the bilge faster than water is comming in it can be very hard to find the source of the leak as it will be under the level of water now in the bilge.

Sent from my SM-J120FN using Cruisers Sailing Forum mobile app

[jamescorfu]

I have 400W for my sailing in the Med, and that is plenty for me, but make sure you look at what you are planning on using electrical wise and calculate you KWH. All the best

[ullar]

Originally Posted by Cotemar

Solar is all that’s needed for electrical needs when cruising.
Its Silent, efficient, clean and maintenance free.

NO Hydro Generator or Wind Turbine is needed for any kind of cruising, including a circumnavigation.

Remember it only takes 17 to 20 days to cross any ocean and you will spend 95% of your cruising time at anchor.
.
.

Wrong,
wrong
and
wrong.

1. Solar needs maintenance. Both, regulators and panels develop problems. But that isn't the biggest thing with them. There just isn't enough sun every day!
2. It's SO GOOD to have both - hydro and wind (additionally to solar). I'm so glad I was able to source an used DuoGen by Eclectic Energy before we started our cruise. We had many days with not enough sun on both, Atlantic and Pacific, but had enough boat speed to cover the lack of solar charge using our DuoGen. And when on anchor in a windy place, we convert it to the wind mode. I can honestly say that people who argue against the hydro (or wind) don't have a clue what they are talking.
3. It is of course possible to over live these 17 to 20 (more likely 17 to 35) days going over an ocean charging with the diesel generator or alternator on main engine and many people are doing just that. However, it's highly likely that solar won't cover all parts of your ocean crossings. (I don't know from where comes that myth of cruising on anchor? May be what people really mean under that is just living aboard?)

[daysgoneby]

Originally Posted by richard45cdo

Good day, Not sure if to get a Hydrogenerator before i start cruising the world.

Plan is to sail a new Beneteau 41 from UK to caribbean(stay for 1 or 2 years) then head of to USA for a while.

im struggling to understand if the Hydro will do much when im sailing aound the Caribbean? or should i get a wind turbine? i will have solar. will solar be enough to run basics off?

your advice much appreciated, as this is all new to me, as based in UK and not done much cruising.

I think you will love the Hydrogen. going from the UK to the Caribbean, but once there you will not get much use out of it. In your case I think going with a tow gen. would be the way to go.

Tow Generator