Aerogenerator questions

[ChrisOlson]

Methinks there was quite a bit of science went into those boats.
Controlling them is where experience counts but those boats were of such radical design I'm sure the learning curve was steep even with years of experience

Almost assuredly. Those low drag speed hulls are about like going from a VW Bug to an open-wheel Formula One car in the automotive world. Even though the principles of sailing it are the same, you don't want a novice crew on it. The Oracle AC45 has a five person crew, and there is no room on the crew for even a single novice

--
Chris

[russ]

Did anyone see the America's cup races.
They were hitting speeds of close to 50 mph in winds of 20

Just the highlights but they have been great - love it when the cats are out of the water totally - only the foils submerged.

[Naptown]

Methinks there was quite a bit of science went into those boats.
Controlling them is where experience counts but those boats were of such radical design I'm sure the learning curve was steep even with years of experience

[ChrisOlson]

Did anyone see the America's cup races.
They were hitting speeds of close to 50 mph in winds of 20

You bet. Sailing is an art, not a science. You can study books until your eyeballs bug out and you still won't be a sailor. The only thing that makes a real sailor is years of experience.
--
Chris

[Naptown]

Did anyone see the America's cup races.
They were hitting speeds of close to 50 mph in winds of 20

[ChrisOlson]

And if a boat it tacking crosswind, the wind over the sail (and to some extent over the bow) can be much larger than the wind speed.

When you are sailing on a reach, sailboats can pretty easily run 2x the wind speed. It's the same principle as to why the tips of wind turbine blades can run 6-10x wind speed. The sail has the shape of a wing - it is an airfoil and it creates lift, and you have to trim the sail so it runs at the right angle of attack, just like an aircraft wing. So the wind coming off the main sail can be up to 2x relative wind speed over the bow.

That's why people that have wind turbines mounted on sailboats mount them so the wind coming off the main sail can drive the turbine. And the reason in the first place, why those little turbines work so good on a sailboat and not so good on a motor yacht. Like our boat will do about 14 knots at best fuel economy cruise with two 600hp Cat diesels burning 15 gph each. We've been on a cruise and had sailboats, some of them bigger than our boat, pass us up on nice day with a 10-12kt crosswind, not burning a single drop of diesel fuel. I've seen some sailboats with fast hulls flat out haul and there are few motor yachts built that could keep up.
--
Chris

[wedgeantilles]

Aerogenerator questions

I think your turbine will be a lot of fun for you. But I don't know how much energy it will produce for an off-grid system. It is designed to be used on a yacht where when the boat is under way the wind will trickle charge the house batteries in the yacht. We have a 58 foot yacht moored at a marina on Lake Superior and it used to have one of those little turbines on it (except a different brand) but we took it off because it never worked very good. We put 1.5 kW of solar panels on our yacht instead, on top of the pilot house.

The main thing is that a small turbine that size is not a real high energy producer, so I would not expect a lot from it.
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Chris

Dear Chris,

The olg guy is spinning connected to the 24 Vdc batteries.

In a few days will know if he is able to charge the batteries.

We will have fun, and we will learn a lot from him, for sure.

Let's wait a few days and see if we can use some watts from him.

The rest of the off grid power is coming from solar panels and a 24 Vdc battery bank, all installed and designed reading posts from this forum, plus the little things I know by myself. Happy with it. And my friend is not a heavy consumer, this is also important.

All the best,

[inetdog]

Wouldn't the wind turbine keep changing directions. It could face into the wind pushing the boat or into the wind coming over the bow of the boat depending on which wind was blowing harder or does it even work like that?

It would indeed face in whatever direction it needs to. But if the boat is running downwind the relative wind from behind will be slower than the actual wind speed relative to the earth.
And if a boat it tacking crosswind, the wind over the sail (and to some extent over the bow) can be much larger than the wind speed.

[ChrisOlson]

Never had need for that much battery

2 group 31's was sufficient for a week long cruise.

Yep - it depends on how big the boat is and how much electrical equipment you have. Most of the live-aboard sailboats in our marina have 600-800ah 12V house banks. The ones that have wind turbines use the wind coming off the main sail to drive the turbine.
--
Chris

[Naptown]

Never had need for that much battery

2 group 31's was sufficient for a week long cruise.

[ChrisOlson]

That was not my experience in 25+ years of sailing with small diesels.
But I also modified the pulleys on the alternator and replaced with high output alternators so I could charge at lower Rpm's

Even so you're lucky to get 500 watts of charging power. Depending on the size of the boat, if you have four 4D's onboard that are half sacked you're usually looking at 12 hours to charge them up with any setup I've seen on a sailboat. That's why the little turbines are so popular. They help maintain the battery if you're going to be at sea for a couple weeks so when you do have to run the Yanmar to charge them up it doesn't take as long.

With motor yachts it's different because you have a couple 600+ hp marine diesels down in the engine room that can easily power dual 135A 24V alternators, and they're running all the while you are under way. Although I still see a few motor yachts with those little turbines - mostly Ampair 300's.
--
Chris

[Naptown]

That's right. For anybody that has done much sailing, you got some serious wind in your hair most of the time. Those small marine wind turbines are extremely popular on sailboats to charge house batteries because the small Yanmar propulsion engine and onboard generator are usually too small to charge the batteries.

Even on our yacht where we have twin Cat 3406 diesels, the alternators on the propulsion engines only charge the house bank at 28.8 volts. The solar or shore charger can absorb them at 31.9V, which is required for proper absorption charging. So the propulsion engine's alternators can only be used to maintain them when underway, never charge them.
--
Chris

That was not my experience in 25+ years of sailing with small diesels.
But I also modified the pulleys on the alternator and replaced with high output alternators so I could charge at lower Rpm's

[SunEagle]

On the average, a sailboat is unlikely to be running directly downwind all the time.

Wouldn't the wind turbine keep changing directions. It could face into the wind pushing the boat or into the wind coming over the bow of the boat depending on which wind was blowing harder or does it even work like that?

[ChrisOlson]

On the average, a sailboat is unlikely to be running directly downwind all the time.

That's right. For anybody that has done much sailing, you got some serious wind in your hair most of the time. Those small marine wind turbines are extremely popular on sailboats to charge house batteries because the small Yanmar propulsion engine and onboard generator are usually too small to charge the batteries.

Even on our yacht where we have twin Cat 3406 diesels, the alternators on the propulsion engines only charge the house bank at 28.8 volts. The solar or shore charger can absorb them at 31.9V, which is required for proper absorption charging. So the propulsion engine's alternators can only be used to maintain them when underway, never charge them.
--
Chris

[inetdog]

Depends on the direction a sailboat is going in relation to the wind

On the average, a sailboat is unlikely to be running directly downwind all the time.