Wind generators

[diamondjim]

Can anyone shed some light on Wind generators? Specifically, (1) electro-mechanical (load dumping) vs computor controled units? (2) Do they interfer with the boat's performance? (3) Recomendations on wind generator?
Thanks,
<> Jim

 

[escapade]

the wind blows free?

Jim;
I have no personal experience, but my good friend/duck hunting partner does.
He has one on his 42 Whitby ketch (mounted on mizzen). It does work, but balancing of the blades is critical. Also, there is the expense of maintaince/initial cost, extra weight aloft, etc. He and his wife cruise the Bahama's for 6 months a year, living aboard the full time. This year he rebuilt his generator (new bearings & brushes) & has bought a Honda generator. He expects to use the Honda & solar panels for the bulk of his energy needs. They run refrigeration all the time (not a cold plate) from a bank of 8D lead/acid batteries. Plans on using the wind generator until it blows up again & then getting rid of it. I guess it depends on your situation, but from what he has said it sounds like it's a lot of trouble for what it's worth.
Hopefully someone else can give you another perspective. It may just be his unit. Phil is usually pretty resourceful but this has driven him to give up on it after 3 years of messing with it.
Have fun & sail fast
Bud E34 "Escapade"

 

[Nigel Barron]

Electrical Needs

Ok, so this is going to be a lot of questions, but mostly I am looking for someone to direct me to a place to find information (Lauren?).

I am getting ready to start working with a friend on the next phase of our racing program, a double-handed Pacific Cup or Transpac. What I am curious about is if there are general numbers you can use to assume electrical use during a 24hr day. I assume these items: cabin lights, running lights, SSB, weather fax, laptop, instruments, stereo. For our purposes, we are thinking solar and one of those little Honda generators (which one?). I just don't know where to begin on trying to figure this stuff out. Thanks for any directions.

Nigel

 

[gareth harris]

Jim - I can't shed much light for you, but 1.5c worth: a lot of units can not be used underway, as the strain on the bearings from the precession is high. Some can.

Nigel -
I just finished rebuilding my electrical system over the summer. I recommend Nigel Calder's book, which has a lot of heavy reading explaining everything in detail, available a lot of boating shops.

Pretty much everything electrical you buy tells you somewhere how much power it draws. Nigel Calder has some tables in his book that answer your exact question, but I recommend looking at every circuit you have on your boat, and making a list of its current draw, and how much you will run it. For example, a typical marine tungsten bulb uses about 0.7A, so your three running lights, on for 10 hours, will use 21 Ah. Stereo depends a lot on the volume, if you have an ammeter in the system you can turn on such items and see how much they are using.

My book, and all my calculations are in storage right now, otherwise I would pass them on, but I did figure that by going to LED lighting (running lights, anchor light, cabin lights, a tiny fraction of tungsten filament power draw), I could run everything except refridgeration off a solar cell mounted on the cockpit stanchions. Bear in mind that is planned for latitudes<33N. I had one 4D, and then I kept one small house battery for engine start only, so running the alternator was my backup.

Take a look at my post on refridgeration a few minutes ago for my thinking on battery capacity. This winter I was planning to install a fridge, and towed water generator to power it, but bad weather has stopped play.

Gareth
Freyja E35 #241 1972

 

[gareth harris]

Nigel - Something else that may be helpful:

Power = Voltage X Current. I.E. for a marine device that lists its wattage but not its current, divide the wattage by 12 (assuming 12V system). Thus a 12W device draws 1A of current.

Forgive me if I am stating the obvious to a man with a physics degree....

Gareth

 

[eric35II]

load calulations

i agree with gareth. you have to list every electrical peice of equipment that's on the boat. when i worked on ocean racing boats one of the requirements was that the absolute minimum battery power was 3 hours ssb key down time. ssb draws 30 amps key down. then list every piece of equipment. don't forget the bulbs in all the instruments. there not mentioned in the power draw of the instrument. once you've gone over the boat twice then add it all up and don't forget the 90 amps for the ssb. that is your absolute load. from this point you can walk thru your daily routine and determine what your working load is going to be + 10 %. i would recommend a high quality battery monitor. it will take the guess work out of the battery condition.
to charge the batteries the most popular generator is the honda's. compact and quiet. gareth had a good idea using the water generator. solar panels only work during the day and are most efficient in bright sun. so are only useful during the day. a wind generator although noisy work 24 hours and depending on the wind have varied output. the water generator also works 24 hours a day. they are more prone to failure then the other two. because it is in the water.
you will have to determine at what percent to recharge the batteries. is it better to run the generator more frequently for a shorter period of time or run it less frequently for longer. if you determine that 75% is the charge point it wouldn't take long to bring the batteries to full charge. you will have to determine by the daily load and the charge rate of which ever means you are maintaining the batteries when to recharge the batteries.

that's my 2 cents
happy boating
greg