Thursday, January 08, 2015

Jevons Paradox, U.S. Version

I spent enough time calculating these graphs for something I'm working on for YCC that you'd better believe I'm going to post them here as well.

U.S. electricity usage per capita; hasn't changed much in 15 years:

Next: Primary energy usage is all energy used -- for electricity, manufacturing, transportation, agriculture, flushing the toilet, feeding your cats, and everything else  For the US as a whole it's now about 3.32 terrawatts (trillion watts; annualized) -- that is, we use 3.32e12 Joules of energy every second, averaged over the course of a year (FYI: 1 kilowatt-hour = 3.6 megajoules), down from a peak of 3.39 TW in December 2007. (The graph below is per capita.) These numbers are decreasing only slowly -- about 0.2% per year, on average -- and then (for the most part) only in recessions, as in the first half of the 1980s, and the 2000s just as Bush Jr took office, and after the financial crisis in 2008: 

The next graph is primary energy intensity -- how much energy it takes to produce a dollar of GDP (goods and services). I deflated the GDP numbers with the GDP Implicit Price Deflator; basically the same as the Consumer Price Index. "2014-dollars" are as of Nov 2014. 

Energy efficiency has given us a factor of 2.8 in energy productivity since 1973 (42 years). And we're spending most of that by consuming more energy (see graph 2, above) -- the essence of Jevons Paradox

All the data are from US EIA and the FRED database from the Federal Reserve in St Louis. You can look them up yourself.


Jon said...

"Energy efficiency has given us a factor of 2.8 in energy productivity since 1973 (42 years). And we're spending most of that by consuming more energy (see graph 2, above)..."

If that's the text you want to write, shouldn't you have a graph 2 in which the quantity being tracked over time is higher in the present than it was in 1973?

John said...

Jevon's paradox it no more paradoxical than (or perhaps has been co-opted by the ad business) the possibility of spending more by purchasing 10 items "on sale" rather than only one item at the "regular" price.

Also, see hierarchies of infinity, below.

And, as previously revealed, my favorite, essentially a re-statement of said paradox: "Too Smart for Our Own Good" by Craig Dilworth

There are many youtube video lectures in praise and awe of scientists (and mathematicians).

This thread on Paul Dirac will get you into the early 20th century physicists:

John Puma

Jon said...

BTW, how do you get a factor of 2.8 in energy productivity since 1973 when chart 3 shows a value of ~4,4kwh/$ in 1973 and a most recent value of ~2.0kwh/$? Shouldn't the ratio be 2.2?

Getting back to my earlier comment, I wouldn't have objected if you'd left it at "we're spending most of that by consuming more" but for some reason you had to tack on the word "energy" and make the statement not precisely accurate. And I disagree that that is the essence of Jevons Paradox. It's not enough for there to be some rebound effect as a result of energy efficiency making consumption cheaper and as far as I know no one serious disputes that there is. There's no paradox until and unless the rebound effect is strong enough to raise energy consumption higher than it was before the efficiency gains.