September 8th, 2009


an interesting graphic

From Lawrence Livermore National Labs, old link an interesting graphic showing the flow of energy in the US (units are, I believe, 10^15 BTUs).

It implies some unsurprising things, like we should stop driving SUVs and turn off the lights when we leave the room. But it also implies some more interesting things:

  • US natural gas usage exceeds demand domestic supply; switching from oil to gas might improve efficiency some but isn't going to change our petroleum imports much.
  • Electricity generation and distribution is nearly as inefficient as a passenger car and mostly coal-fired to boot. Plug-in hybrids don't help the big picture unless they're also part of some kind of distribution efficiency improvement.
  • Freight is pretty efficient comparatively speaking. Dicking around with how we power semis is not going to help much.
  • Doubling solar every 18 months (the current growth rate and not coincidentally equal to the doubling time in Moore's Law) won't even be noticeable for over a decade. It will take WWII-level increases in production for this to make a difference.
  • Doubling wind could make a difference sooner than that, and even fractional differences in nuclear output would make a big difference.
  • Geothermal makes a bigger difference than you'd think.