Bicycle as generator/power source?

During the winter I sometimes ride on a trainer, and think about how
much energy I'm expending and how it would be cool to harness it to
power, say, my espresso maker.
I finally did a quick google and found this:
http://www.freerepublic.com/forum/a3ab928b76932.htm
which is pretty close to what I envisioned. He uses this contraption to
charge batteries that power devices.
Has anyone seen a marketed version of something like this produced? I'm
not electrical engineer, and for the right price I'd be happy to forgo
the experimentation.
And, yes, I'm well aware of friction light generators. I have two of
them.
/s

"Scott Gordo" wrote in message
oups.com...
During the winter I sometimes ride on a trainer, and think about how
much energy I'm expending and how it would be cool to harness it to
power, say, my espresso maker.
I finally did a quick google and found this:
http://www.freerepublic.com/forum/a3ab928b76932.htm
which is pretty close to what I envisioned. He uses this contraption to
charge batteries that power devices.
Has anyone seen a marketed version of something like this produced? I'm
not electrical engineer, and for the right price I'd be happy to forgo
the experimentation.
And, yes, I'm well aware of friction light generators. I have two of
them.
/s

Tacx (www.tacx.nl) do 2 versions of their trainers (Fortius and Cosmos I
think) which generate and feed into the domestic mains AC supply. Quite
natty, but expensive.

Skippy

Scott Gordo wrote:
During the winter I sometimes ride on a trainer, and think about how
much energy I'm expending and how it would be cool to harness it to
power, say, my espresso maker.
Not a chance! 8-) They draw a kilowatt on the heater.

http://www.freerepublic.com/forum/a3ab928b76932.htm
which is pretty close to what I envisioned. He uses this contraption to
charge batteries that power devices.
I adapted a small Nippondenso alternator to a CycleOps exercise stand.
The driven roller was about 3x larger than the shaft shown in the
website, it was _still_ hard to pedal against a useful load (a car battery
and a small TV).

Has anyone seen a marketed version of something like this produced? I'm
not electrical engineer, and for the right price I'd be happy to forgo
the experimentation.
If you want enough power to run a laptop computer or a radio, human power
might be (sparingly) useful. I'd not want to depent on it.

bob prohaska

On 30 Nov 2005 08:37:33 -0800, "Scott Gordo"
wrote:

During the winter I sometimes ride on a trainer, and think about how
much energy I'm expending and how it would be cool to harness it to
power, say, my espresso maker.
I finally did a quick google and found this:
http://www.freerepublic.com/forum/a3ab928b76932.htm
which is pretty close to what I envisioned. He uses this contraption to
charge batteries that power devices.

The protagonists of Harry Harrison's _Make Room, Make Room_ (you might
know the *******ised movie version _Soylent Green_), living in Malthusian
overcrowded New York of.. well, actually, pretty much today, IIRC, but
seen from 4 decades ago, use exactly such a device to charge some 12 volt
car batteries that power a small fridge and a reading light or two.

Jasper

On Thu, 01 Dec 2005 05:44:57 GMT, bob prohaska's usenet account
wrote:

If you want enough power to run a laptop computer or a radio, human power
might be (sparingly) useful. I'd not want to depent on it.

http://laptop.media.mit.edu/laptop-images.html

Human-powered or AC powered as you choose, laptop costing $100 in
quantities of a million or so. They are considering bringing versions of
this on the market for Westerners as well -- I know I'd buy one at 2-300
or so to take on my vacation.

http://www.prepare-now.com/809.html

Crank-powered radio. Originally developed for the third world, now also
sold for disaster use in the West.


Jasper

bob prohaska's usenet account wrote:
Scott Gordo wrote:
During the winter I sometimes ride on a trainer, and think about how
much energy I'm expending and how it would be cool to harness it to
power, say, my espresso maker.
Not a chance! 8-) They draw a kilowatt on the heater.
snip
bob prohaska

And that's too much for a car battery that's recharged every so often?
(Sorry, I'm just barely above saying "Magic" when asked how many
electronic devices work.)

/s

If you are able to crank along at 250 watts continuous for 4 hours. (Must be
a good rider to do this) you would generate 1 kilowatt hour which would cost
about 16 cents average in the USA. (4 cents per hour) I doubt you will fine
a product on the market with this low of a payback.

On Thu, 01 Dec 2005 18:43:41 -0500, Larry wrote:

If you are able to crank along at 250 watts continuous for 4 hours. (Must be
a good rider to do this) you would generate 1 kilowatt hour which would cost
about 16 cents average in the USA. (4 cents per hour) I doubt you will fine
a product on the market with this low of a payback.

For that kind of money, there's no way you could afford to replace the
calories burned!

Matt O.

Matt O'Toole wrote:
On Thu, 01 Dec 2005 18:43:41 -0500, Larry wrote:

If you are able to crank along at 250 watts continuous for 4 hours. (Must be
a good rider to do this) you would generate 1 kilowatt hour which would cost
about 16 cents average in the USA. (4 cents per hour) I doubt you will fine
a product on the market with this low of a payback.

For that kind of money, there's no way you could afford to replace the
calories burned!

And there are very very few humans that could do 250 watts continuously.
A healthy human can sustain about 0.1 Hp, which is about 75 watts.

Larry wrote:

If you are able to crank along at 250 watts continuous for 4 hours. (Must be
a good rider to do this) you would generate 1 kilowatt hour which would cost
about 16 cents average in the USA. (4 cents per hour) I doubt you will fine
a product on the market with this low of a payback.



You'd also generate about 6,000 Btu of heat (latent +sensible) to warm
up the room - or 0.06 therm, worth about another nickel at natural gas
prices... more if you heat with propane.