View Single Post
Old 06-08-2014, 09:10 PM   #35 (permalink)
elhigh
Master Novice
 
elhigh's Avatar
 
Join Date: Jan 2008
Location: SE USA - East Tennessee
Posts: 2,314

Josie - '87 Toyota Pickup
90 day: 29.5 mpg (US)

Felicia - '09 Toyota Prius Base
90 day: 49.47 mpg (US)
Thanks: 427
Thanked 616 Times in 450 Posts
Quote:
Originally Posted by mort View Post
You can probably generate hydrogen at home cheaper than the equivalent energy of gasoline. But storage and transportation in the car is likely to be very expensive.

-mort
This is the one part of your answer I find highly questionable.

Given the best proton exchange method and high quality platinum electrodes and optimized voltages and whatever ultra-top-drawer catalyst you might have handy, you might see 80% efficiency. The power delivered via the grid is already conveyed by a lossy, inefficient system, must we compound that loss further with yet another conversion?

Every conversion necessarily carries a commensurate loss in efficiency; you cannot get a perfect outcome by using X kilojoules worth of electricity to generate X kilojoules worth of hydrogen, which would then yield X kilojoules worth of energy when you used the hydrogen (however you used it). You CANNOT. The universe doesn't work that way.

As lousy as they are with their 20-25% thermal efficiency, gasoline engines actually do a pretty good job of getting things done. The gasoline is ignited to release heat, expanding the gases in the cylinder, pushing on the piston, turning the crank and driving the car.

If you want to do that with hydrogen, then take all the losses in the simple process I just described as a percentage, multiply them all times each other, and then multiply that by whatever percentages represent hydrogen. Don't forget the losses in the national power grid, they're pretty significant. Estimates suggest maybe, on a very very good day, about 50% of the heat energy in the coal actually comes out of consumers' wall sockets as usable power. Usually it's a lot less.

Hydrogen has huge potential, I won't argue that. But it will require a radical leap in how it's generated before it's ready for prime time, and the assorted HHO systems haven't found it.

NOTE: I am not an engineer, physicist or chemist. I'm halfway smart and am paraphrasing several articles I've read on the subject. I may have missed some finer points but I'm confident I got the meat of the matter correct.
__________________




Lead or follow. Either is fine.
 
The Following 2 Users Say Thank You to elhigh For This Useful Post:
pgfpro (06-08-2014), UltArc (06-08-2014)