crossposted from Voices on the Square
In the online support for the April, 2013 Scientific American article on Energy Return on Investment (EROI), Scientific American online interviewed Charles Hall, developer of the EROI concept, on whether Fossil Fuels will be able to maintain economic growth. In one of his answers, Charles Hall responds to the question:
What happens when the EROI gets too low? What’s achievable at different EROIs?
He says:
If you’ve got an EROI of 1.1:1, you can pump the oil out of the ground and look at it. If you’ve got 1.2:1, you can refine it and look at it. At 1.3:1, you can move it to where you want it and look at it. We looked at the minimum EROI you need to drive a truck, and you need at least 3:1 at the wellhead. Now, if you want to put anything in the truck, like grain, you need to have an EROI of 5:1. And that includes the depreciation for the truck. But if you want to include the depreciation for the truck driver and the oil worker and the farmer, then you’ve got to support the families. And then you need an EROI of 7:1. And if you want education, you need 8:1 or 9:1. And if you want health care, you need 10:1 or 11:1.
Civilization requires a substantial energy return on investment. You can’t do it on some kind of crummy fuel like corn-based ethanol [with an EROI of around 1:1].
A big problem we have facing the alternatives is they’re all so low EROI. We’d all like to go toward renewable fuels, but it’s not going to be easy at all. And it may be impossible. We may not be able to sustain our civilization on these alternative fuels. I hope we can, but we’ve got to deal with it realistically.
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