China and Nuclear Power.. Failsafe / Never Melt Down!

[K6-III]

Personally, I don't actually see the hydrogen economy coming about.

Fuel Cells may very well be used in place of diesel generators, but by no means will they be used everywhere.

I sense that CAT (compressed air technology) engines would make much more sense. You can read more at www.theaircar.com

Your losses are much lower for making LN2 from air than for electrolyzing water to make hydrogen. In that case, nuclear can be orders of magnitude better than fossil fuels.

[Brian Ellis]

I'm not convinced about compressed air or LN2. Compressors are terribly inefficient as is evidenced by the heat they generate. This is, of course, because the compression is adiabatic. Unfortunately, I know of no way of isothermally compressing a gas.

Apart from that, the autonomy of an air car is very limited, because there is only so much energy that can be stored into a couple of cylinders.

FYI, an electrolyser, if it is designed to run non-stop, can reach 75-85% energy efficiency (i.e. electricity in to the energy recoverable from hydrogen), which ain't bad. A distribution system would typically be 80% efficient (i.e losses of H2 and cost of transportation or pumping). A FC is, with today's technology, 45% not counting the starting time and 70% of the electricity produced could be used for driving the motors at 95% (the other 30% for battery charging, aircon, heating, radio, lights, etc.). The overall energy efficiency from power station to wheels is therefore about 19%, which is much worse than from refinery to wheels with a modern IC engine. This will be partially compensated by not requiring quite as much energy with a lighter car, but it won't make that much difference.