Reply #25: Energy Balance For Ethanol Better Than For Gasoline? [View All]

I have dealt with the USDA studies in previous essays, showing the shoddy and misleading methodology they use. But let’s now examine this claim of energy efficiency. Would it surprise you to know that not only is this claim false, it is WAY FALSE?

Let’s do some quick calculations to demonstrate this. A barrel of crude oil contains 5.8 million BTUs (2) of material that will ultimately be turned into gasoline, diesel, jet fuel, etc. It is well-documented that the average energy return on energy invested (EROEI) for crude oil production is around 10/1 (3). Therefore, we will use up about 580,000 BTUs from our barrel getting it out of the ground. The other major input occurs during the refining process, and it also takes roughly 10% of the contained BTUs in the barrel of oil. The total energy input into the process is 1.16 million BTUs, and the energy output was 5.8 million BTUs. The EROEI is then 5.8 million/1.16 million, or 5/1.

For ethanol, the USDA study reference above showed that for an energy input of 77,228 BTUs, an energy output (when co-products were included) of 98,333 BTUs were generated. The EROEI is then 98,333/77,228, or 1.27/1. The efficiency of producing gasoline is then 4 times higher than for ethanol, which makes sense when you think about it.

http://www.consumerenergyreport.com/2006/04/08/energy-balance-for-ethanol-better-than-for-gasoline/

Another ethanol hack bites the dust.