Ethanol – The Black Hole of Energy Costs?
Mark Chu-Carroll has a great post up pointing out the silly arguments being used to dismiss ethanol as an alternative fuel.
One thing I’ve been hearing a lot lately is discussions about Ethanol, and it’s been really pissing me off. Can ethanol be a serious replacement for oil as a source of energy? I don’t know. Because both sides are using really bad math to make their arguments.
There are two fundamental questions about ethanol as fuel where the bad math comes in:
- How much energy does it cost to produce ethanol compared to the amount of energy released by consuming ethanol?
- How much pollution is generated by the process of producing ethanol?
Now you might have noticed Mark doesn’t believe in mincing words. He also doesn’t obscure the math. The premise being bandied about here is that it takes 1.3 gallons of gasoline to produce 1 gallon of ethanol. Since it takes 1.5 gallons ethanol to replace 1 gallon of gasoline, you have a net energy loss. Just stick with gasoline, it’s cheaper.
This silliness dates back to a study by David Pimentel, a Cornell Professor, who has studied ethanol for the last 20 years. He did an extremely (his critics say too extreme) complete analysis of the amount of energy needed to produce ethanol. How extreme? He included the calories used by the workers harvesting the corn to make the ethanol in his calculations.
Towards the end of Mark’s post, where you will go after you finish reading this, he points to a feature from Minnesota Public Radio discussing ethanol. This has the stop-the-argument-in-it’s-tracks quote.
Pimentel’s analysis is so detailed it yields some big surprises when it’s applied to other energy sources. Take gasoline. Pimentel says if all the energy used to make the fuel is considered, gasoline, too, is a net energy loser.
“If you include the pumping and processing and so forth, it runs a little over 10 percent,” says Pimentel.
Oh. Gas is energy negative as well; ethanol is only about 20 percent worse. That doesn’t do the anti-ethanol crowd much good.
Of course what bunched my panties, both about Mark’s post and the MPR feature, is that neither mentioned where the energy in ethanol originates. Corn you say. And from where does the energy in corn come? Corn is a fairly inefficient but cost effective solar collector. Unlike a silicon solar collector, corn converts solar energy to chemical and not electrical energy. The nice part about the chemical energy in corn is that it is easily stored, transported and processed. That’s what makes the idea behind bio-fuels so cool. Be it ethanol or canola oil (increasingly being used as a diesel alternative in Germany), bio-fuels are ultimately solar powered.
Bio-fuels are also CO2 neutral. MPR didn’t get that point. They even passed on the gas lobby talking point.
Ethanol opponents question whether the fuel is a higher quality energy source. They say it adds to air pollution.
The amount of carbon produced when they are burned comes from the atmosphere in the first place. While this is also true for fossil fuels, the carbon in gasoline was also in the atmosphere originally, that atmosphere was here millions and millions of years in the past and not part of the current ecosphere. That makes a big difference because the biosphere can only absorb so much CO2, that’s why the concentration (about 335 parts per million or ppm) is low but increasing. If we stopped putting ‘old’ carbon back into the atmosphere, that number will start going down again.
But pro or con, it is an energizing debate – just as long as you get the math right.