[pct-l] Electricity on the go - full equation

[Paul Mitchell]

If you ARE interested in these fuel cell products and you want to weigh them
against other energy options, then this is relevant.  Otherwise it's little
off-topic for the list, so sorry all for the deviation.  

> I think they generate electricity through an internal reactive process
that usually results in small amounts of oxygen and hydrogen as a byproduct,


You're right, the cells do output clean energy, but that's not the full
equation.  They require a flow of hydrogen - pressurized hydrogen for larger
Polymer Exchange Membrane Fuel Cells (think cars) and in the case of the
device in question the hydrogen is supplied via the "tea-bag" packets which
contain hydrogen embedded in aluminum powder.

> The whole idea of fuel cells is that they are supposed to be
environmentally inert or at least that was the bill of goods I was sold.

Exactly, that was the pitch, but the math on that only works if you omit one
very important part of the equation - the production of hydrogen.  Hydrogen
needs to be generated, and although there are multiple methods, the dominant
method is to generate hydrogen from natural gas, a process that is
approximately 80% efficient.  That means (more or less) that for every 100
units of natural gas energy put into the process, 80 units of hydrogen
energy come out the other end.  As such, hydrogen is not an energy source,
it's an energy storage medium and represents a net-energy-loss.

On the surface it seems great, hydrogen is clean, it's not a carbon fuel -
but if carbon fuel is used to produce it, and you get less energy out then
you put in, then ultimately hydrogen energy is a lie both in terms of long
term cost viability and environmental impact.
 
So this little cell charger does require hydrogen input, and outputs spent
aluminum fuel packets - tea-bags.  Not as clean as it might seem at first
glance.  Maybe it's better than batteries, maybe not.  The full energy
input/waste output equation would need to be calculated for both and
compared.

Hope I'm not coming across as preachy, I just find the subject interesting.

Cheers,
Potential 178
www.hikefor.com