H/O Alternator vs. Wind Gen

[Strygaldwir]

I was pondering the difference between a high output alternator and a windgenerator. I wondered after some thought why you'd select an alternator for a sailing boat? Some of the thoughts had in comparing them were as follows:

o Cost. By the time one purchased the external regulators for the alternator the cost between a moderate 400 watt alternator and a say 75-100 amp alternator is comprable.

o Installation. The installation of the alternator is less onerous. Perhaps there are issues if you are changing the footing of the alternator such as when going from a small to a large frame unit.

o Output. I assumed that one would run the high output alternator for 1 hour or so daily to keep the batteries topped up. In that one hour 100 amp unit is going to put out about 1300 watts of usable output. the 400 watt wind generator will have to get something like 4 hours of output within the 24 hour period to equal this output.

o Operating cost. The windgerator seem like it would be MUCH less expensive over its life. There is little operating cost that I could think of. I expect the lives of the two system to be comperable. But, 1 hour of fuel is going to cost me about $2.75. So if I am using both daily, the yearly operating cost of the alternator is going to be around $1000. (I assumed $3.00 per gallon for diesel fuel and 365 day running. My engine consumes about .75 gallon per hour)

o Depreciation cost. I assumed the generators life was Identical. I know there is maintenance and depreciation on the marine engine running the alternator. I am adding about 300 hours per year of run time to my engine. If we assumed a useful life of an engine to be 10,000 hours, that would mean I would be fully depreciated in 30 years. If I take the cost of an engine, say $10,000 and spread the run cost over 30 years, I get about $333 per year of depreciate cost to run the alternator solution.

o Invironmental cost. I am ecologically aware, not a zealot. Seems like the impact of running my engine vs the wind generator on the ecology is almost a no brainer.

o Annoyance factor. I get far more annoyed when people are running their diesel engines around me in an anchorage or marina than ANY noise I have ever heard from ANY wind generator. Noise and the SMELL!!! Phew. Not to mention the danger of CO poisoning from our engines.

o Range. I can run my engines for 116 hours before I have to refill. Not a big issue. That gives me 116 days before I have to refill. But I will be competely empty. Not really that big a factor. Unless of course I want to use my engines to move someplace, that will decrease the fuel available for the alternator.

o Loads. I can run bigger loads from the alternator. Still not enough to run the Scuba compressor, but the microwave is not a problem. Hmmm.... Microwave is not a problem for the wind generator and batteries either???


o Charging while running with the wind. The wind generator has poor output when sailing down wind. Well the alternator has the same problem when SAILING down wind, or upwind, or reaching, or running...


o Charging while there is no wind. That's the gotcha. No wind, no power from wind generator. Well, I wasn't thinking of getting rid of the existing alternator. But, I am going with solar panels to resolve that issue.

o System redundancy. If I run down my batteries, for instance my bilge switch gets stuck . I can still get going by waiting for my wind generator to recharge me! I always have the additional system to provide backup energy!

So, what am I missing???? Why do we spend the money on high output alternators.

Fair winds

Keith