Wednesday, April 23, 2008

How To Think About EROEI

Some eco-zealots claim the nuclear industry has an EROEI of 10 or 2 or even negative. Ha!

The right way to think about EROEI is to invert it. 1/EROEI is, more or less, the proportion of your industrial economy which must be devoted to producing energy. This assumes the energy industry is no more energy-intensive than other sectors of industry. A not-unreasonable assumption.

So if you have an EROEI of 10 then 1/10th or 10% of your industrial economy must be devoted to producing the energy for the rest of the industrial economy. If you have an EROEI of 30 then this falls to 1/30th or 3%, for a 7 percentage point difference.

Given that booms to recessions happen on a change of just a few percentage points in production, 7 pps of energy overhead matters a hell of a lot. Actually, even pushing up the EROEI to 90 reduces the overhead to 1% which improves the industrial economy. Pushing the EROEI beyond 90 can't improve the industrial economy significantly and that would explain why it isn't done.

Having said all that, you have to ask yourself whether or not you would have noticed if 1/10th of ALL industry everywhere (steelmaking, concrete kilns, road building, automotive, aerospace, shipbuilding, even television manufacturing) was devoted to just producing energy.

You have to ask yourself whether an EROEI of just 10 for a vital component of the energy sector (and nearly ALL of the energy sector of France) passes any kind of sanity checks.

And if you still want to know, nuclear power has an EROEI of 90.

No comments: