View Single Post
Old 12-09-2010, 09:13 AM   #199 (permalink)
needs more cowbell
dcb's Avatar
Join Date: Feb 2008
Posts: 5,038

pimp mobile - '81 suzuki gs 250 t
90 day: 96.29 mpg (US)

schnitzel - '01 Volkswagen Golf TDI
90 day: 53.56 mpg (US)
Thanks: 158
Thanked 267 Times in 210 Posts
Originally Posted by NeilBlanchard View Post
So, the reason the natural gas electricity plants can be so much more efficient is cogeneration -- you could have the gas turbines, then use the heat to power steam turbines, and then use the heat for nearby buildings. Copenhagen (apparently) has their efficiency up around 80% by doing this sort of thing.
Well, copenhagen is on the cold side, average high temp in august is 68 degrees, so they can make use of the heat from the power plants directly for much of the year.

Other municipalities might be better off making electricity out of it and sending it where it is needed.

Originally Posted by NeilBlanchard View Post
Sounds great to me! And it makes electric cars look even better.
I'm not so sure anymore, there are some serious issues using electricity in cars. Power to weight, Range, Cost, Efficiency, size, refueling time. I'm starting to think Algae or other biofuel is the best solution for vehicles (with some Rankine added downstream of the ICE, or??).

Here is a site which suggests that roughly 1/5 as much land is needed to power a car with Algae vs Solar panels: Fat Knowledge: Algae Biodiesel vs. Solar Panels

and if you look at the picture below, even the best batteries are weak in the energy density department (which means lots of dead weight and limited range and/or performance/efficiency):
lithium ion battery is in the very lower left corner

The edison crew also posted on FB about it recently
Welcome to Facebook

Last edited by dcb; 12-09-2010 at 10:19 AM..
  Reply With Quote