On Jan 11, 2008, at 7:56 AM, Michel Jullian wrote:
I understood the sentence as referring to some pneumatic version of
regenerative braking, but
admittedly it was unclear.
What amazes me with this compressed air energy storage thing is
that it is so dead simple, isn't
there a catch somewhere?
Let's see how much energy they store in their 300 litres at 300
atmospheres, it's P*V isn't it?
P*V= 300*10^5Pa * 0.3m^3 =~ 10^7 J = 10^7 W.s = 10^4 kW.s
Yes - I get 9.12x10^6 W s = 9.12x10^3 kW s = 2.53 kWh.
Mmmm... only about 10000/3600 =~ 3 kWh????
Which is wrong, me or Jed's beloved Wikipedia? http://
en.wikipedia.org/wiki/Compressed_air_vehicle :
"300 litre air at 300 bar only amounts to about 12kWh (the
equivalent of 1.4 litre (0.37 gallons) of
gasoline)"
The above should be 0.075 gallons of gasoline., or 0.28 liters.
Probably me, the maths must be more complicated than P*V...
correction welcome.
Looks to me like you have it right and Wiki has it wrong.
Michel
----- Original Message -----
From: "Jed Rothwell" <[EMAIL PROTECTED]>
To: <[email protected]>; <[email protected]>
Sent: Thursday, January 10, 2008 3:57 PM
Subject: Re: [Vo]:Photos of Guy Negre's compressed air car on CNET
News.com
A Cnet report:
Fill'er up:
http://www.news.com/2300-11389_3-6225395-4.html?tag=ne.gall.pg
This one says:
"Here's where you fill 'er up with compressed air. The air drives
the pistons in the engine, and
the engine returns the favor by recompressing air for later use."
A perpetual motion machine!
These reporters are such idiots.
- Jed
Horace Heffner
http://www.mtaonline.net/~hheffner/
