Richard Ha writes:
This Scientific American article talks about fossil fuels, economic growth, and why I'm always talking about the importance of our (much cheaper) geothermal energy here.
It looks at the work of Charles Hall, who talks about how the energy it takes to obtain energy, minus the energy you use to get your food, equals your lifestyle. That formula – energy return on investment, or EROI – lets us compare how we live now with how Hawaiians lived in older times. It allows us to compare apples to apples.
I know Charlie Hall very well. I brought him to Hawai‘i to give talks about this at UH Hilo and Manoa, as well as to visit Puna Geothermal Venture and our farm.
From the Scientific American article Will Fossil Fuels Be Able to Maintain Economic Growth? A Q&A with Charles Hall:
Q. What happens when the EROI gets too low? What’s achievable at different EROIs?
A. 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.
Do you think we're facing limits to growth now?
I think if you correct the U.S. GDP for debt—in other words, the debt is some kind of not-real growth—then I think the GDP hasn't grown at all since 2005. It's just grown through debt. I think clearly growth has declined; it's possible that growth has either stopped or may soon stop.