On Thu, 18 Jul 2002, Lawrence Lile wrote:

>How much power is developed by a [overwieght middle aged and balding] human
>on a bicycle?  I am thinking about 25 watts, but my memory is as bad as my
>hair.

About 300W at the beginning of the trip ;-) (roughly 1/2 hp). If you have
a very good bicycle (circuit tyres inflated to bursting pressure minus
0.0001 whatevers, perfectly aligned frame, bearings, etc), on flat hard
clean road (preferred: waxed parquette), you could probably coast at 1-3
km/h on 50W.

>A fuel cell, hydrogen storage and hydrogen generator combo that could
>deliver 30 watts on the fuelcellstore site looks like it might cost about
>$2000 smackeroons.  While that might seem like a lot of $ for a moped
>battery, it would double the power that I could put into my bike, perhaps
>raising the speed by half or so.  Pretty interesting.
>
>Now, if we were STORING the fuel cell output in a battery, say running the
>fuel cell longer than the bike runtime, we could signifigantly reduce the
>size of the fuel cell required.
>
>Many bike motor systems also include regenerative braking in a simple way.
>A 24 volt motor is run on two 12 volt batteries in series.  when the
>batteris are switched in parrallel, the 24 volt motor will charge the (now
>12V) motor.
>
>Our fuel cell size can get smaller with this idea as well.  Including a
>little duty cycle factor in the size of the fuel cell because of
>regenerative braking.
>
>How small a fuel cell could we get away with here, and how small a tank for
>a 30 minute commute?  Could one carry an hour's worth of hydrogen on board
>at reasonable cost?

Before you get into this consider that you need at least 0.1g acceleration
to be able to participate in traffic (otherwise than as a casualty) imho.
What is reasonable cost ? 2 x 30 minutes on the bike without motors or
anything may save you enough money on medical bills in 15 years, that you
could buy a proper fuel cell car ;-) ;-).

>(debaters on the safety of hydrogen storage should check the fuelcellstore
>site for safety catalytic storage media before flaming.  I saw a demo of
>these where an incindiary bullet was fired through one without setting it
>off.  An adjacent gas tank didn't fare so well)
>
>
>--Lawrence
>Who still thinks a $10 battery charger is going to come out cheaper

Do you HAVE to throw the sad truth at everyone like that ? ;-)

Peter

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