Wind Generator or Solar

[Wynand N]

When cruising the deep blue, which is superior to keep the batteries charged?
Solar panels or wind generator

[Ssor]

Consider the following: solar is effective when the sun shines, which doesn't happen at night or during days that are overcast. In the high latitudes the days can be quite short during the winter and will be quite long in the summer.
The wind blows without regard for day or night, or cloud cover,or it may not blow at all. It doesn't care how long the daylight lasts. Solar may require more deck space per ampere hour than wind. Wind may require more maintainance or repairs than solar.
When you finish weighing all of the pros and cons you may end up deciding on one or the other for cost considerations or because you like the look on one more than the other..Which is best? I expect each has its advocates that can argue convincingly for the rightness of their preference.

[D'ARTOIS]

Wynand, regarding the Solar Power issue, you must take a few given facts into consideration. This I learned from an old electrical engineer who owns now a solar cell company in Holland.

I will look up where I have put his calculations, I kept those, not for a boat but for my house in France that I want to make autonomous and independent from any outside source.

After you have calculated the overall loss you have, - a loss depending on many factors - a moderate number of continuous output will remain. I understand that you know the basic elements of the photovoltaic system, and that you know that the energysupply depends on daylight and the intensity of daylight, expressed in degrees Kelvin. When the sun is on a vertical angle, between 1200 and 1300 you have about 5600 degr. Kelvin. A moderate system supplies you with 2 amps per hour over daylight, less when the sky is clouded etc. The solar system therefore, won't work all the time.
The other options are: a windgenerator and a powergenerator connected to your propellorshaft. That is free energy too.
Make to begin with, an E-balance. In the E-balance are all your electrical connections listed and from this list you will take a certain number that represents the daily use of electricity.

[Skippy]

Both. This has several advantages: First of all, your power generation will be more consistent. Wind will work when it's not sunny, and solar will work when it's not windy. Second, this will allow both sysems to be smaller and lighter than they would be otherwise, since you can charge the battery more slowly and evenly. I think that's also good for the battery. Third, you then have a redundant system, so if one breaks down, you can still limp home with the other one. It's also conceivable you might be able to get by with a smaller battery, since it shouldn't have to go as long a time between charges.

[D'ARTOIS]

Yes Skippy, I failed to mention your point.

You really have to get replys from other boaters who have each type IN YOUR SAILING AREA. Sails and salt spray block a lot of light from hitting the cells. Sails block the wind a lot or reduce it's power to the generator. Top of the mast limits size. Dragging the prop should be much more effective than the other 2 combined.That can provide a lot of constant power. Electric generator is out of the salt spray, should last the longest.

[MikeJohns]

Go for the lot, prop or towed alternator, Solar panels, and a wind generator.
Wind generators vary considerable in quality output and noise. Some are prone to fly apart, they do not work in strong wind and need to be locked.
Rotating props tend to pick up debri ropes nets plastic. Solar panels are very good for a low power budget but need supplementing.
Towed rotor driven alternators can be a pain to retreive without a cone snubber but are much easier to clear of fouling than a boat propellor.

There is one brand that can be used as a wind or a towed rotor alternator.

[finavar]

http://www.ampair.com/htdocs/

go to 'Yacht-based Power' then click on the Aquair tab at the bottom for more info.

These have been around for a while and have the support of some very experienced blue water sailors.

finavar

I do not know how fouled the prop gets. BUT. If you mount the prop INTERNALY, with a pipe facing foward below the water line and exaust the water. It can be BACK FLUSHED while at speed as often as needed. Simple to service. I won't bore you with the obvious. Call me if you would like some help. -----------------You realize all these systems are probably useless in a storm. When you need them most.