Wind Generator Idea

[forsailbyowner]

My next project boat is going to be electric powered. I kicking ideas around and was wondering about..... Having a separate mast that includes a rather large wind generator assembly on top. Instead of having a generator head aloft, using a pinion/ driveshaft assembly and putting the generator head below. To make it really confusing Im looking at making a it 3 tube assembly. One that follows the wind direction for an autopilot capability, one fixed and the inner driveshaft for power generation. Ive never seen a windgen set up this way. Many old windmills ran a pump via driveshaft.

[wristwister]

I'm guessing the reason we don't see this sort of thing on boats is because of innefficiencies due to friction loss. You'll have at least one and maybe two 90 degree gears, plus a bunch of bearings for that long shaft and the gearing, plus all the momentum of those components, might render the whole idea too inefficient compared to a typical fan mounted directly on the generator shaft.

[Stumble]

Is the wind generator supposed to provide motive power or just charge the batteries?

Generating motive power is a terrible idea mostly because of the size of the wind generator needed and it's associated issues. As a battery charger they are well understood and while generally underperform compared to solar work well.

[dlymn]

Friction, tipping force from a heavy mass high in air
, as many braces as the mast, unpredictable winds, variable wind gusts, voltage regulators currently clumsy devices that turn off when they generated voltage hits say 14.4volts and so even when it's windy you can't capture the energy all of the time.
Deep cycle batteries very heavy, expensive, limited life (talk to a Prius owner)
You need 25 kw continuous to rival a small diesel. (12v X 2000 amphours )

[Terra Nova]

Originally Posted by forsailbyowner

...Instead of having a generator head aloft, using a pinion/ driveshaft assembly and putting the generator head below...

Once you start applying physics and engineering you'll see why wind generators are not designed that way. Too much friction losses and rotating mass.

[forsailbyowner]

Originally Posted by Stumble

Is the wind generator supposed to provide motive power or just charge the batteries?
.

The wind is just one of the battery charge methods, Solar will be maxxed out in the available space, propellor generation, and a backup diesel generator. Battery bank will be substantial.

With the larger blade capabilities comes more torque. There will be some losses yes, but having the unit belowdecks also allows for rpm adjustments during design to take full advantage of whatever alternator or generator head is used for the power production.

[skipmac]

Originally Posted by dlymn

Deep cycle batteries very heavy, expensive, limited life (talk to a Prius owner)

Off topic but since you bring it up.

First, the Prius doesn't use what is commonly referred to, at least in a boating context, as a deep cycle battery but instead a nickel-metal-hydride battery.

Then not certain what you call limited life but the car comes with an unlimited 8 year, 100,000 mile warranty and so far failure rate is very, very low, even for cars with over 200,000 miles. New battery pack is about $2600 if replaced outside warranty which I consider not all that expensive for a hybrid car battery.

[gts1544]

Stumble, I would like to point out that your operating area has a lot to do with the efficiencies of power generation, solar or wind. We have an electrical engineer within our group sailing in the Virgin Islands and he has concluded, with our steady 15 kt trade winds 24/7 and an efficient wind turbine, that wind is the way to go for us, far out stripping solar. Just another point of view! gts1544 - George

[GILow]

Originally Posted by forsailbyowner

... Many old windmills ran a pump via driveshaft.

Not sure about that one... Usually (here in Oz) the gearbox is at the top with the blades and all that comes down to ground level is the conrod for the piston, which is way below ground. The friction losses would be too great otherwise.

Matt

[GILow]

P.S., this feels like one of those cases where the wind resistance of the whole assembly will far outweigh the motive force it is capable of supplying.

[mbianka]

Vibration will be an issue too. But, hey why not build a model and see if your concept works then see where you go from there. Some things are counterintuitive:

https://www.youtube.com/watch?v=F7PNSyAfCjk

[sailorboy1]

Originally Posted by forsailbyowner

My next project boat is going to be electric powered. I kicking ideas around and was wondering about..... Having a separate mast that includes a rather large wind generator assembly on top. Instead of having a generator head aloft, using a pinion/ driveshaft assembly and putting the generator head below. To make it really confusing Im looking at making a it 3 tube assembly. One that follows the wind direction for an autopilot capability, one fixed and the inner driveshaft for power generation. Ive never seen a windgen set up this way. Many old windmills ran a pump via driveshaft.

What is the motivation for taking a fairly simple wind generator and turning into a complex assembly with a lot of additional moving parts, and then trying to install it on a 33' boat?

[Cotemar]

Here is an example to follow.

Windmill Sailboat: Sailing Against the Wind : TreeHugger

[a64pilot]

Originally Posted by skipmac

Off topic but since you bring it up.

First, the Prius doesn't use what is commonly referred to, at least in a boating context, as a deep cycle battery but instead a nickel-metal-hydride battery.

Then not certain what you call limited life but the car comes with an unlimited 8 year, 100,000 mile warranty and so far failure rate is very, very low, even for cars with over 200,000 miles. New battery pack is about $2600 if replaced outside warranty which I consider not all that expensive for a hybrid car battery.

The failure rate of the Prius "traction" battery is so low that many are available in junkyards from late model low mileage cars very cheaply because there essentially is no market for them . Some people are installing additional battery packs in their Prius and making home made plug in hybrids because it's so cheap to do.

I wonder how difficult it would be to adapt the Prius battery packs to Marine use? They are around 400 V but that can be dealt with. Readily available and relatively inexpensive, high power density and light weight?

I think the newer Prius uses a Lithium based battery?

Sorry for the thread drift, but it has to do with electric propulsion, biggest drawback to that I think is affordable electric storage capacity / weight. Hybrid car battery packs may help there.

[Tx J]

Allowing as you are apparently wanting to convert a mizzenmast to a windgen, your best bet might be a VAWT (vertical axis wind turbine): https://en.wikipedia.org/wiki/Wind_g...al_axis_design .

However, building something like this from scratch might be something of a "project".