Dirty truth about biofuels
The net energy value of biodiesel and ethanol is very hotly debated. There are many net energy studies of biofuels, particularly ethanol, which give a wide range of values. The main problem is that net energy studies are easily influenced by biases. The researcher must choose the energy inputs and outputs and the values to assign to these various inputs and outputs. There is no clear standard. However, in a survey of a large sampling of ethanol studies, the authors found that the average of all these studies taken together showed a net energy loss of 8%. Throwing out the three highest and three lowest outliers cut this loss to 2%.1
In this report, while we will discuss the net energy profile of various biofuels, we will also bring up several other criticisms of biofuels and the biofuel industry that are not so controversial, nor so open to debate.
gdenby:
I found this article to be quite substantial, and was fairly convincing that the production of bio-fuels are a net loss. Don’t take my word for, read through the piece, even though it is somewhat technical. Its worth re-iterating the conclusion:
“Our energy needs would be much better served if we would practice energy conservation, strive for better energy efficiency, and divert current biofuel subsidies to the development of affordable and more efficient solar cells and wind turbines.”
One of the main problems with the conversion of bio-mass to some transportable energy source is the depletion of the soil after the product is removed. There has been some interesting recent work on the development of “bio-char” as a soil ammendment. Derived from archeological study of deposits of “Terra Preta do Indio,” this seems to me a very positive development. I hope such developments are pursued as a sort “air-bag” against the coming crash.
If you garden, consider trying a small scale experiment. Take 1/3 each of crushed charcoal (not charcoal briquets, the mistake I made last year), sand, and commercial nitrogen fertilizer, and add to your soil. The original mixture was broken charcoal, pot shards, kitchen waste, fish remains and probably urine. With a sufficient amount, fertile self-replenishing soil was developed in the otherwise nutrient poor Amazon soils.
gdenby
14 February 2007, 10:23 amBob H:
I think there’s a tendency to discuss biofuels by only looking at what corporations are proposing (e.g. corn ethanol and Archer Daniel Midland). I think it’s safe to say that with profits and consumer capitalism in command, no fossil fuel alternative will be truly sustainable.
I notice that the article cited leaves out discussion of things like enzymatic transformation of cellulose into ethanol (which would greatly reduce the need for fossil fuels) or algae as a biofuel source.
I found this article to be useful in outlining the potential for biofuels:
http://www.theoildrum.com/story/2006/11/27/0432/3533
For me the main point is that biofuels have a lot of potential in the context of social transformation (rejecting consumerism and transcending capitalism).
Speaking of charcoal, this article
14 February 2007, 12:59 pmhttp://www.goodnewsindia.com/Pages/content/discovery/karve.html
has an interesting discussion of small-scale conversion of agriculural waste (sugar cane leaves) into charcoal for local consumption.
G.:
If these “bio-fuels” were to meet our demands, we’d have nowhere to grow food.
14 February 2007, 6:02 pmDeAnander:
relevant discussion of the ethanol scam
The Silver Calf: biofuels as a denial mechanism
Get real, get busy: Kunstler on powerdown
14 February 2007, 8:24 pmLegume Sam:
Biofuels are a guerrilla strategy — “yellow oil” is important because the restaurants have to pay to have it dealt with as “toxic waste” when it can be converted into fuel.
Meanwhile, the capitalists need people to keep pretending that capitalism will last forever — the futures markets depend upon this illusion. Biofuels are part of the illusion-making process.
15 February 2007, 2:26 pmBill McCormack:
The whole concept of bio-fuels is something dreamt up by the oil companies and as such has to be viewed with skepticism.
I get tired of watching TV programmes giving the impression (or actually saying) that these things are more green than fossil fuels, the truth is that growing, fermenting and distilling ethanol will produce more CO2 than the using fossil fuels. I watched a car programme last night (19 Sept 07 - Pulling Power in the UK)that was showing the latest Saab that runs on E85 and it showed a couple of bods (from BP, Esso or Shell I imagine) taking a handful of a kind of rough flour and showing how it could produce a liquid of 8-10% alcohol - which was probably more than the mass of plant material they started with (Seriously).
What they forgot to mention was:
You get less mpg from ethanol
What is that bubbly gas you see during fermentation? Oh the CO2 you mean!
How much energy does distillation use?
Distillation produces an etahnol/water mixture NOT pure ethanol - how much energy does the drying process use?
They did not quote the Saab’s Kg CO2 per litre of fuel and I am not sure SAAB are quoting this yet.
Ethanol does have some advantages - it burns cleaner, petrol (& diesel) tend to produce a lot of carbon (soot and smoke) and CO although I do not know how far modern engines have gone to solving this. But ethanol does burn cleaner because it contains one Oxygen atom per ethanol molecule - this also explains it lower mpg figure, ie one of the carbons is more oxidised than any of the carbons in hydrocarbon compounds (petro or diesel).
In my mind the only solution to our energy problems is to run electric cars and produce energy from nuclear fuels. Now I am not representing the Nuclear industry (I am a chemist turned programmer) and the thought of an increased nuclear program scares the pants (and socks) off me. But if you can think of anything better please let me know. btw I agree that Wind and Wave should be explored and research should receive better financing for these two technologies but I do not think they will produce enough.
Bill Mac
19 September 2007, 5:33 am