×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Fuel Cell as a Battery

Fuel Cell as a Battery

Fuel Cell as a Battery

(OP)
OK, so I'm pretty much of the opinion that if a hydrogen-based fuel cell serves any purpose whatsoever, it's pretty much as a replacement for lead-acid batteries.  So my question is, how good a battery is a fuel cell?  In terms of:

1. cost - my guess is batteries win, otherwise NASA wouldn't be about the only ones using fuel cells (based solely on practical justifications).

2. weight - no idea.  My guess is lead batteries are heavier, otherwise NASA would be using batteries.

3. size - no idea.  My guess is batteries have the advantage.

4. environmental considerations - Original energy source is not an issue UNLESS one technology is more efficient (and therefore requires less input energy for the same output).  Assume hydrogen explosions are not a problem.  We should account for nasty solar cell manufacturing processes, platinum membranes, etc, on the fuel cell side as well as discarded lead and acid on the battery side.  

5.  lifespan - batteries are typically replaced every 5-20 years depending on the battery, some are rated for 90.  How long will a fuel cell last?

6.  maintenance - there's 5 to 10-year maintenance free batteries, and 20-year high-maintenance batteries (check water & ph).  What's the required maintenance on a fuel cell?

7.  reliability - I'd assume a 10 year battery would last about 8 years.  I'd assume a fuel-cell would be about as reliable as a battery for 80% of its life too.  Any thoughts?

Any thoughts on which one looks like the best choice for stationary vs. mobile applications?  Any other considerations I've missed?  Anyone feel like defending the flywheel (or the "flux capacitor") instead as the energy storage device of the future?

RE: Fuel Cell as a Battery

(OP)
PS -- we should also assume a "reasonable" density of hydrogen compression, whatever that is. . .   perhaps a high-pressure gas?  And that a "magic beer keg" has been invented to store the hydrogen, something that won't blow up but doesn't weigh a ton either. . . .

RE: Fuel Cell as a Battery

(OP)
Oh yeah, one more criteria:

8.  energy loss - batteries lose charge over time.  Is hydrogen loss an issue, or will the fuel cell "retain its charge" indefinitely?

RE: Fuel Cell as a Battery

(OP)
Sort of -- althought I was thinking more in terms of kWh than mWh batteries when I posted this. . . .

For mWh batteries, it seems like the only question is can they provide a higher power density than batteries, safely, with relatively good reliability and all at a reasonable cost.  Any environmental benefit there over batteries would be incidental (with respect to market acceptance) -- if people can run their laptops and cellphones for two weeks straight off a fuel cell the size & weight of a battery, someone will buy it for nearly any price.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources