Which 400w Wind Generator Is Best

[seandepagnier]

Hi,

I don't have time to build a wind generator, but I will need one to power my autopilot. I will have some solar panels (already ordered 30 watts) but they are not going to be enough.

I have here two possible ones:

¤ Discount Solar: Your source for low cost, high quality solar panels
NEW Sunforce Model 44444 12V 400 Watt Wind Generator - eBay (item 220370714923 end time Aug-28-09 11:19:30 PDT)


both generators look extremely similar, so is there any difference or should I go with the cheaper one? I have heard a lot about the air-x ones, but it's more expensive.

Other suggestions appreciated as well.
Thanks

[barnakiel]

You can't rely on wind / solar for your autopilot unless you have a lot of wind / sun.

Air X best value, but noisy. The new one claimed less noisy but browse recent threads as someone noticed 'less, but still a lot'.

Beware not all Air-X are marine grade - there is also an Air-X fore household use.

If you can get a windvane, get one. If it has to be an autopilot make sure your alternator regulator is of the newer smarter kind.

b.

[seandepagnier]

I would prefer a windvane, but I cannot afford more than $1000 for a working unit.

I'm pretty sure I will generate enough power to keep the autopilot on, it uses 20 watts max.

[barnakiel]

Beware the 20 Watt max may be quoted for a specific work cycle (Raymarine and Simrad quote 25 on 75 of, so if you have one of these, the realistic figure is in the 40-80 Watts range). I think the 25% is achievable only for well tracking hull in perfect conditions.

I believe the top-notch gyro models do eat less but they are more expensive and they consume more in stand-by (due to much developed brain boxes)).

Now a windvane is a completely different story - zero electrical energy consumption and nearly silent - big advantages for an offshore sailing vessel.

If you have the power and if you can afford a good auto then off course you have very good reasons to go for auto.

Remember to allow for apparent wind speed drop on the windgen if you do a lot of downwind sailing. Esp. in the trade winds area where the winds are often less than 15 knots true (below 10 apparent).

b.

[seandepagnier]

it would be quite interesting to hack apart an autopilot and control it directly with a computer program. If the program had input from gyros accels and magnetometers, and possibly the ability to lock the motor "so when waves push hard against the rudder, zero power is used, and the rudder holds. Then it would be possible to have much lower power consumption.

I would much rather have a windvane, or pendulum controlled by an autopilot would be the best, but to start out, just a regular autopilot will have to do.

[mbianka]

Originally Posted by geckosenator

Hi,

I don't have time to build a wind generator, but I will need one to power my autopilot. I will have some solar panels (already ordered 30 watts) but they are not going to be enough.

I have heard a lot about the air-x ones, but it's more expensive.

Other suggestions appreciated as well.
Thanks

I installed a a 48 volt Air X Marine on my boat. Yes it is a little louder than some of the other generators out there but, I don't find it objectionable. It has some nice features like shuting down when the battery voltage reaches a certain voltage which it constantly measures. This helps prevent overcharging the batteries. When used in conjuction with the solar panels it is usually in this shutdown mode during the day because the solar panels are keeping the batteries topped up. When the sun goes down and the battery drops below it's set point it starts operating again. Once it charges the battery back to the set voltage it shuts down again. I often notice that my Air X is shutdown while others wind generators keep spinning and spinning. Mines been operating for over a year and I've had no problems with it.

Mike
THE BIANKA LOG BLOG

[04 Marine]

Sometimes old is new. Many years ago I would drag a small prop on a cable that was attached to an alternator on the stern. Never produced much more than 300W, but it was in todays terms dirt cheap to build, easy to repair and parts were readily available at your local auto parts store. Loss of speed was a fraction of a knot. Noise was not an issue either. It's not the be all end all but it is one approach to an old problem.

[seandepagnier]

do you think I could hook up an alternator to the shaft of the inboard?

[barnakiel]

Attaching alternator to shaft of an inboard would require the shaft to be supported both before and aft of the power take-up (belt?).

You would meet with some other issues, like e.g how to replace the belt once the original one breaks (the shaft is continuous). Also, the alt has to run at specific rpm to deliver - you might need a special alt for that or a proper set of pulleys.

Also, the shaft does not turn freely - it is limited by the transmission, the cutlass and the 'inefficient' flow of the turbulent water (as compared to a screw dragged say 50 yard beyond the boat).

b.
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