July 22, 2005
Cornell: Biofuels Not Worth It
Sustainable Triad is a great resource about environmental concerns and sustainability from my local area (the North Carolina Piedmont Triad). He just posted a story the other day about biofuels, one of the alternative energies I really like, and it's not a happy story.
For ethanol production, if corn, switch grass, or wood is used as the source, the amount of fossil fuel consumed in production is greater than the equivalent ethanol output by 29% to 57%, depending on the source (corn is best, wood is worst).
UPDATE, 7/25/05 - Today we have this story, which discusses a new process for creating Biofuel from Biomass that creates TWICE the amount of usable fuel as other processes. There might be hope for Biofuels yet.
For biodiesel production, if soybean or sunflower plants are used as the source, the amount of fossil fuel consumed in production is greater than the equivalent biodiesel output by 27% (soybeans) to 118% (sunflowers).
Note this important point: The claim is not simply that the energy input is greater than the energy output. Rather, the claim is that the fossil fuel input is greater than the useful (ethanol, biodiesel) energy output. Well, that's not good. The whole point of the substitution of ethanol or biodiesel for gasoline is to consume less fossil fuel, not more.This is bad news. If it takes this much fossil fuel to produce biofuels, with a 27% difference between petroleum input and biofuel output, what will we do when the petroleum is gone? Biofuels would be useless then. Peter, the blogger, said to do a Google search for "ethanol Cornell University," which I did, and found the story. The study found that:
- corn requires 29 percent more fossil energy than the fuel produced;
- switch grass requires 45 percent more fossil energy than the fuel produced; and
- wood biomass requires 57 percent more fossil energy than the fuel produced.
- soybean plants requires 27 percent more fossil energy than the fuel produced, and
- sunflower plants requires 118 percent more fossil energy than the fuel produced.
There is some good news for biofuels, thank goodness.
Although Pimentel advocates the use of burning biomass to produce thermal energy (to heat homes, for example), he deplores the use of biomass for liquid fuel. "The government spends more than $3 billion a year to subsidize ethanol production when it does not provide a net energy balance or gain, is not a renewable energy source or an economical fuel. Further, its production and use contribute to air, water and soil pollution and global warming," Pimentel says. He points out that the vast majority of the subsidies do not go to farmers but to large ethanol-producing corporations.At least there's that.
So, what does this tell us about alternative energies? Still, so far, there's nothing that's going to let us break away from cheap oil. There's simply, so far, no alternative energy resource or combination of alternative resources that is going to give us a sustainable future under heavy energy use. I think that once the oil is gone, so will our ideas of how we interact with the world using external energy sources. We may, for better or worse (and I think better in the end), have to start living sustainably and delicately once again. Let's just hope that our past mistakes won't keep that from being possible.
UPDATE, 7/25/05 - The other day, I posted this story about Biofuels and the possibility that they're inefficient - that the amount of petroleum used to process usable Biofuel might make the process unsustainable. Well, today we have this story, which discusses a new process for creating Biofuel from Biomass that creates TWICE the amount of usable fuel as other processes.
About 67 percent of the energy required to make ethanol is consumed in fermenting and distilling corn. As a result, ethanol production creates 1.1 units of energy for every unit of energy consumed. In the UW-Madison process, the desired alkanes spontaneously separate from water. No additional heating or distillation is required. The result is the creation of 2.2 units of energy for every unit of energy consumed in energy production.This is extremely good news for Biofuels, which only this weekend were looking like they might be already on their way out...
"The fuel we're making stores a considerable amount of hydrogen," says Dumesic. "Each molecule of hydrogen is used to convert each carbon atom in the carbohydrate reactant to an alkane. It's a very high yield. We don't lose a lot of carbon. The carbon acts as an effective energy carrier for transportation vehicles. It's not unlike the way our own bodies use carbohydrates to store energy."
Posted by George at July 22, 2005 10:51 AM Category: Alternatives
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I don't entirely agree that there is nothing that will "let us break away from cheap oil." Clearly oil will predominate until which time it is no longer available. But methane gas seems to me a very viable alternative, and I can't see why a combination of technologies won't be the wave of the future. I am not an engineer, or a scientist, but wind, solar and methane combined seem to hold promise if we can retool the machines that require fuel.
I DO heartily agree with your statement that we must "start living sustainably and delicately once again."
I am also quite wary of University studies, which, as result of drastic federal funding slashes, are now funded by private interests.
Posted by: Pamela at July 24, 2005 1:12 PM
Well, there's a problem with renewable energies, and that's this: even if the energy itself is renewable, the necessary catalysts, storage, conversion equipment, etc are not.
Solar energy requires silver and, in alot of cases, plastic. Nuclear, though not very green, is indeed a powerful option. Of course, Uranium is limited. Biofuels require massive agricultural reform, and then (at least according to this study), they would use too much energy input to be worth it. Hydrogen is plentiful and basically inexhaustible (we think), but fuel cells often use plastic, metals (which obviously aren't infinite), and other non-renewable materials.
The list goes on.
Posted by: george at July 25, 2005 7:08 AM
Good point about the catalysts, storage, conversion equipment of alternative energy sources being non-renewable. Although I do feel--for instance in the case of methane--that we have the product and storage facilities in abundance, that now, as has been done successfully in several instances, we just need to convert existing processes, or build new ones. How long do these types of facilities generally last? In other words, if we were to build systems out of non-renewable materials in order to accommodate more renewable sources of everyday energy, how long do those kinds of structures last? Would their longevity offset the initial cost, both financially and materially? Perhaps I'll see if I can find any information giving us some answers ... or does anyone else know?
It seems clear that we will have to recreate our habits--and I think that it is good that you highlight that as the main point of your post.
Posted by: Pamela at July 25, 2005 3:23 PM