Solar Power?

Jerry, You are not nuts, at least in this community.

I am assuming you have a 12v system so using OHM's law  the watts needed is Amps x Volts.  Using 13 volts as a base that puts your needs as 144 watts - in the best of sun angles.  Round that to 150 watts. If you want to keep your energy needs at near zero.  Now look around at the panels available.   There are many but come in 2 distinct flavors - solid and flexible.   Solid panels have in general more power per square inch,  flexible has the advantage of going around curves.  Each a compromise.  Where have we heard that before?  You may have to do the C word for your needs. 

Spend a little time looking around and you can then self-diagnose. 

JIm

 http://news.soliclima.com/images/cont/solar_challenger.jpg

Thanks for your reply, Jim.  And, yeah, those are about the figures I came up with, so it looks like the big C is certainly operative.  A solar panel the size to produce that much power will definately NOT fit under my greenhouse, and I am reluctant to change the aerodynamic configuration of the airplane by mounting flexable panels on the outside of the plane. It looks like the most probable C is to plug in the battery charger whenever I can, consider using a smaller solar panel only on the ground as a trickle charger when AC is not available, and limiting my length of flight to what will be supported by the battery powering the bare minimum of eletrics ... radio and intercom when outside of B or C airspace, transponder only when needed and lights never....

 

 

That said... How about a RAT  (http://www.ghetzleraeropower.com/lowspeed.htm 

This device - in less commercial form - could provide you with the needed power.  A homemade one would be pretty easy. Only the mounting bracket would be difficult. 

Being a professional sailor we think about every possible way to provide the ever increasing power needs for sailboats. Naturally the RAT is on the list right with PV panels. 

http://www.nauticexpo.com/cat/water-electricity-lighting-for-boats/boat-wind-generators-underwater-propeller-power-supply-generators-IB-988.html

Water driven propellers have not been as successful as they have a tendency of getting eaten by sharks under tow. 

Might want to do a search to see if someone has already developed a unit for the homebuilder - I bet there is....

JIm

Just could't let it sit like that.

http://www.aircraftspruce.com/catalog/eppages/gennipod.php

 

http://www.pipercubforum.com/windgen.htm

 

there has to be more....

Similar - -  http://www.basicaircraft.com/turbo-alternator-bpe-14.asp

Jim and Alice,  Thank you, thank you, thank you!  I had an advertisement for a wind generator a couple of years ago, but can no longer find it, and a google search did not turn up anything that would work on an airplane.  What you two have located for me should do the job nicely.  Now I just have to decide which one to get and save my pennys.  Should be ready to go by next spring.  Thanks again.

 

some big differences in $$$ between the units.  Ask the manufacture for contacts for an honest assessment.

BTW - I got my contacts through Google.  It depends on how nicely you ask. 

j

  A semi silly question- why not see what you have to do to add a alternator?. I would think something along the lines of a small tractor alternator- or possibly a lawnmower (the ones I'm thinking of are for Kubota  engines)? I'd think somewhere around 20-30 amps would be plenty.  Rough figure of .5-.75 hp to drive (figuring 14 volts X 30 amps = 420 watts, 420 / 746 = .56 hp)

I would think your drag loss with a  ram air turbine would be much higher, and your expense higher to boot. You might talk to a alternator rebuilder and get some ideas.

 "BTW - I got my contacts through Google.  It depends on how nicely you ask. "

Guess I didn't smile broadly enough

As I remember it I searched for "wind generator" and got a lot of stuff available for blocking approaches to runways with twirling fans, but nothing that would fit on an airplane.  Thanks again for the contacts and I will do some research on the products listed.  I was intrigued by the Piper Cub answer - converting a starter to a generator by adding a propeller sounds like a fun project and should be much less expensive than the manufacured models.  The most expensive one does have the advantage in that it comes with the STC already available and no need to involve the FAA for more than a 337.

I'm just guessing that your question about adding an alternator means adding one to the engine and having it engine driven.  Not possible with the Continental A65.  There are no provisions for driving an alternator.  The Lycoming had the gears etc in place and all that was required was bolting on the alternator.  Your idea of using an alternator from a mower or lawn tractor, however, has merit.  An alternator would be lighter than a generator, and if I could find one that would accept a propeller, it could be wind driven.  This could work.  Thanks for the suggestion.  The toughest part would be getting the FAA approval.

 

 

 

  Gerald, Ah, OK, didn't realize it was a A-65. 

Regarding wind generators, this is certainly a humorous solution posted by a fellow Double Eagle builder on our Yahoo group. He recently painted his plane in a British WWI color scheme, his generator looks quite appropriate beneath.

 

LOL.  Form over function or something like that.

 

Hey Jerry, I noticed the last post on this subject was in Nov. If you haven't solved your problem yet, I have an idea for you. Any permanant magnet motor will produce electricity when the shaft is spun. You would have to use a prop with a fair amount of pitch to create enough torque to spin it and run the terminals to a small voltage regulator like the ones used on small engines but it would make a good lightweight charging system.  Hope this helps,       J.

I have an A series Continental engine on my Baby Ace and have been looking for an answer to the same question.  I found a good  way to conserve (at night  anyway) is to trade out your incandesent  bulbs for LEDS.  You can power your running lights and cockpit lighting for about  ONE amp.  If you don't care to night flying, forget that. 

 I have found a small generator and regulator for just over $110 (new).  Now I am trying to decide if I should power it with engine power or wind driven.  Can you mount a small generator (12 volt, 10 amp) as either one?  I'm going to have to build my mount either way.  So...

Would this help answer your question?

Smurf

Here's some more information  on wind generators.  Years ago, a friend had a small solar panel on the nose of his Varieze, but that was to trickle-charge the battery on the ground, not replace the alternator in-flight.

Jerry, if you're still checking this thread, one thing has me curious.  You posted, "According to latest measurements, with everything turned on except the landing light, I am drawing about 11 Amps."

This seems high.  Does it include nav lights?  Normal, daytime power draw should be much less than this, though some comm radios seem to draw an inordinate amount of power even in the receive mode.

I had some generator problems on my Fly Baby, and got by for almost a year just by charging the battery between flights.  Wasn't flying at night, though.

Why not run an alternator from a pulley moundetd on the prop hub AFT of the hub using the lower case split line bolts as mounting points for the braketry.  I'd use a 25 amp alternator and something avialable at an auto parts stor. but a Kubota tractor alternator might do as well. 

Seems like those propeller units would be major energy sinks. With the power of rare earth magnets these days, I wonder if you couldn't just figure out a way to attach some to a part that was rotating, and then put some coils with appropriate numbers of turns nearby. I don't know the details of how airplane magnetos work, but perhaps and extra coil in there would generate power.

If I WAS going to use a ram air turbine, or whatever they're called, I think I'd use one of those brushless motors for model airplanes. Very powerful for the weight. I'd make up a three way rectifier (haven't figured details just yet, and add a voltage regulator.You'd probably want to carve your own prop as normal ones are for thrust, not using as generators.

A really off the wall idea is to use a Peltier junction between your oil pan and a heat sink sticking out of the cowl. If you get one side warm and the other side cold, it puts out current. How much, I don't know.

One of the links already listed and the picture of a generator disguised as explosive ordnance both feature the GenniPod wind generator with integrated voltage regulator as sold by Aircraft Spruce and Great Plains.

I asked Steve Bennett of Great Plains for a recommendation of a simple, lightweight VW setup for a Clutton FRED for my site and he recommended a stock VW distributor/coil single ignition with a battery and a GenniPod.  When I asked about his experience with the GenniPod more recently he had this to say:

"We have sold about 15 and the manufacturer has also sold about 20 units.  They have been in use for about 7 years, commercially for about 3 years."

So there is not a whole lot of experience with this product out there, but Steve's been around for a long time and has a good reputation.  If he continues to sell them then they are probably doing well in the field.  $250 for a regulated powersupply is not bad.  For the price and the relative simplicity of the solution, that seems like a good deal.

Cheers,

Matthew