102 comments on Understanding the current energy crisis in South Africa
Comments can no longer be added to this story.
| Show without comments | PDF version
102 comments on Understanding the current energy crisis in South Africa
Comments can no longer be added to this story.
| Show without comments | PDF version
User login
Personnel
Editors
Contributors
Peak Oil Primers
Archives
- November 2009
- October 2009
- September 2009
- August 2009
- July 2009
- June 2009
- May 2009
- April 2009
- March 2009
- February 2009
- January 2009
- December 2008
- November 2008
- October 2008
- September 2008
- August 2008
- July 2008
- June 2008
- May 2008
- April 2008
- March 2008
- February 2008
- January 2008
- December 2007
- November 2007
- October 2007
- September 2007
- August 2007
- July 2007
- June 2007
- May 2007
- April 2007
- March 2007
- February 2007
- January 2007
- December 2006
- November 2006
- October 2006
- September 2006
- August 2006
- July 2006
- June 2006
- May 2006
- April 2006
- March 2006
Vital Trivia
License
This work is licensed under a Creative Commons Attribution-Share Alike 3.0 United States License.
GAIA Host Collective
More recent work by Ayres (1,2) suggests the link is 70% with exergy, which is the amount of useful work derived from the input energy source (meaning 10btu of coal can provide 0-10btu of exergy, depending on how efficiently you use it). It's similar to "fuel quality", in some sense.
He also notes that the exergy-based analysis explains much more of GDP growth than energy-based analyses, so it's likely that the "smaller factors" you mention were pretty significant.
You can see it for yourself in the EIA's data on energy intensity of the economy. The amount of energy required to produce a dollar of GDP fell only 20% from 1949 to 1980, but has fallen by about 45% since then -- nearly triple the previous rate.
You think that might have something to do with the offshoring of US industry?
That's certainly a factor, but far from the only one. Indeed, the tales of US manufacturing's demise are greatly exaggerated.
See also here or here. US manufacturing is still 20% of the world's manufacturing, commensurate to the US economy's 20% share of the world economy.
Of course, it's worth noting that the world's energy intensity (btu/$ of GDP, inflation-adjusted) has fallen 7-15% in the last 10 years (same EIA data, 15% based on PPP, 7% based on market exchange rates), so it's not like the energy consumption has simply been pushed elsewhere.
Thanks! Good links. I had meant to read that paper by Ayres. He does not quote Hall, Cleveland, Odum, or Constanza in any of his references. It seems he discovered the relationship independently. He found the link between quality and GNp but does not have the two other correction factors that they discovered: product mix and household use. I need to read the longer paper. Thanks again!
It's an interesting paper, but obviously it's only one look at the situation. I imagine that both his "exergy" approach and the earlier "quality, product mix, and use" are attempts to quantify the fact that a fixed amount of energy can be used in very different ways to produce very different amounts of things. It's a key thing to examine, but I'm not sure how best to do so.
At any rate, you're more than welcome - finding, exchanging, and disseminating information is, IMHO, the most important (and bestest) function of the internet.