Stalkerator update

Hi stalkerator fans! ...Ah... Nois... what is a stalkerator???

Don't you read all of my posts throughout all time???  And the comments???    : )?

In the responses to my post "Kepler, what a buoy!" I revealed my invention of a generator based on a stalk of grass.  One reader, greentheo, liked it so much that we continued discussing it in the comments.  The design went through several stages and I have now gotten some numbers together... Oh buoy!  (Actually, the same idea could generate electricity on a buoy.)

The current design is to have our pseudo stalk be a graphite kite tube about 4' tall, perhaps with a ping pong ball on the top for extra drag - like a thistle stalk (make it a steel ball on the buoy).  About 3" - 4" from the bottom you attach some kind of gimbal to hold the stalk while allowing it to bob in the wind as stalks do - ya know?  Below the gimbal you build a coil around the stalk and glue a nail up the tube shaft inside the coil.  below the nail you attach a floating magnet so that the bobbing stalk flops the magnet around under the nail - Cool! An inductance generator!

OK, fine, so would it be any good?  I decided it was time to do a little experimenting.  I had a nail on a coil from some earlier experiments (Gary's "Gary Effect" was a little far-fetched I think... the nail was just following the field lines... another post another day...) If I put the nail end near a stack of my Neodymium super-magnets, I get a measurable current.

Last year or so I tore apart some computer hard drives and saved the very strong control magnets.  They are mounted to steel plates which I think is to strengthen the magnet so they do not explode under their own stress.  They are polarized with the two opposite poles near the middle of the bar with maybe some "dead" space between them.  I decided to try the induction coil on that and got an interesting sensation... The nail head was big enough to span the DMZ, so it just felt like 2 strong magnets, but the nail point gave a different result.  The dead zone almost felt like repulsion as I moved the nail over it.  I do not think it was actually repelled, but I was having to hold the nail away from the magnet, so the reduced pull in the DMZ gave the sensation of repulsion. As I moved the nail point across the zone it snapped sharply across to the other side!  Ah ha!  Just what the stalkerator needs!  I can get up to 16 mV even with my poor coil set up.  I did not measure milliamps.

I grabbed my stack of tiny Neos and made 7 stacks of 4 each.  I arranged 6 of them in a circle around a heavy iron washer with #7 up the middle.  I tried having all the same polarity up, but the nail just sort of smooshed from stack to stack with not much generation.  So I flipped every other stack.  That was better, but what ever pole I picked for the center stack still created sort of a magnetic plateau for the nail to ride.  I eliminated the center stack and got much better action.  The nail seemed to hop from one stack to the next as it had hopped across the DMZ on the HD magnet.  Also, if it did go across the middle it now had a "hole" with significantly lower field strength, so I got some generation even while crossing the center.

With the final configuration and just holding the nail in my hand I easily got 10 mV and .25 mA.  I just measured it with my voltmeter, so these numbers would need to be confirmed with a known load to get accurate results.  Anyway, using those numbers, .010 V x .00025 A = .0000025 Watt.  Wow!  That's Some Pig!  Let's just say that with a great coil, great magnets, and optimized construction we can get that up to 100 times that... why not?  That is .00025 W.

OK, so according to "The Physics Factbook" (http://hypertextbook.com/facts/2003/BoiLu.shtml) the average house uses a bit under 9,000 kWh in a year!  Ugh! There is a long way between those decimal points!  However, one guy cited got that down to 1,000 kWh per year.  If we assumed that we can generate power about half the time and save it until needed, we have 365.24 x 12 = 4383 hours for generation. That would require generation of 228 W (plus change).  Lets see, at .00025 W/unit, that is only 912,617 units!  OK, 1,000,000 units.  (1.09575 Watts per unit per year)

If I put a stalk at the corner of each square foot I could have 1000 stalks in a 100' x 10' plot. Woo Hoo 1 W/year!  Let's suppose I build a papercrete house and a bunch of greentheo energy savings strategies to reduce my need to 1,000 kWh/y.  That is only 1000' x 1000' for the 1,000,000 units!  Gee... if it takes me 1 hour to make, connect, and install each one (after getting the parts and the bridge rectifiers...), then if I have to repair each one after x hours of operation...

My goodness... this is not going well.  A common solar cell gives 1.2 W for each 4" square!  That one cell working for a year would make just over what 500 square feet of my "grass" would make... with no moving parts... not good news for the stalkerator...   : )?