Whenever efficiencies are discussed, it is imperative that all inputs be accounted for.

From the get go, THE BEST multicellular plants IN THE WHOLE WORLD is only 6% efficient in converting sunlight into sugars. The sugars of which are then partitioned into harvestable starches stored in the grains or fruits, and the non-fermentable (at least directly) lignin, cellulose and other complex carbohydrates. During the corn plant's entire stay in the field, and the amount of sunlight it has received, only a mere 1.5% of total energy is captured as grains. The longer it stays in the field unharvested, the less efficient it will be.

We have already lost 98.5% of sunlight energy when we get those grains. Now we have it breakdown enzymatically, first by hydorlyzing under high temperature, then enzymatically by enzymes, and it forms sugars for fermentation, and this is penalized as 20% losses of whatever we have 1.5% of original sunlight captured, thus we only have 1.2% left. Now the sugars to alcohol, we have only an energy conversion efficiency of 56% under best conditions, that leaves finally the original sunlight energy of a miniscule 0.672% of original sunlight that is now trapped in the energy of alcohol.

I haven't even counted the amount of energy in fossil fuels in the planting, harvesting, processing, and the distillation.

Compared this to an average solar cell today with a direct solar energy conversion efficiency of 15%. Biological production of fuel is one of the worst solutions we could ever have. The solar cell is at least 2,200% better than the biological pathway, which means that you would only need 1/22 of land for producing the same amount of energy alloted to crops which are better used as food.


If you would have produced hydrogen from solar radiation, via direct splitting of water, there are technologies today whose efficiency approaches 50% of original sunlight energy captured into energy of hydrogen. And this pathway is even 7,500% better than the corn production method.


But production of ethanol, albeit one of the worst conversion of energy from solar to fuel, is the one that most people understand, and has the chance of giving profits to most people today.

Are you factoring in all of the inputs, Joe? What energy is required to produce those solar panels. Do you have a source of capital to replace those corn fields with solar panels? The corn is utilizing solar energy that frequently be otherwise lost.

I'll still stick with the 134% figure cited in the report and take whatever free energy gets used in the process. The simple fact is that ethanol producers are making profits even before subsidies for ethanol production and even at high corn prices. That would further seem to indicate that more energy is being harvested/produced than consumed.

Oh, and don't forget that ethanol serves a useful purpose in replacing MTBE which people prefer to keep out of their drinking water.

There it is an energy balance not a conversion. Nothing to do with thermodynamic. The gas of the tractor doesn't convert in corn.
The process is hoped to yield more carbon than it burns. That's all.

Joe, ethanol from corn is a much more efficient method of converting energy than your empty roof. You need to walk the talk. Like I said before, it amazes me how people like to blame others for various problems.

Still friends....and eventual wine partners!

Joe, do you know the solar conversion efficiency of switchgrass? I did a quick search, but could not find a % solar conversion. Maybe it is one that you included in the maximum solar conversion rate of plants as 6%. I have read that it is much more efficient than corn and that with both cellulosic ethanol and combustion of lignin byproducts it has a much higher yield compared to corn.

Another aspect of biofuels is to use the bio-waste from crops that are already being grown for other purposes. Some of these can be burned directly, some only require additional transportation, some require additional processing. Many companies are beginning to make efforts to collect that waste (like paper companies are beginning to chip the limbs and needles from pine trees in the field to be used as boiler fuel), but there are many other potential sources that we can use--in most cases it boils down to economy of scale.

I've worked with and built computer simulation models for the Life Cycle Analysis of several types of Biomass Power Plants for the last two years.

We have the best database references that are internationally refereed by credible scientists all over the world and not by any political appointees. If our friends from Europe here who are inclined into environmental research and ecology, they might be familiar when I mentioned the names such as EcoSpold, EcoInvent, Umberto, and in the US, the GREET models as among the few examples.

The term Life Cycle Analysis is a cradle to the grave accounting of all energy, materials, and pollutants involved in producing a product until it is discarded. Any type of man-made product has its associated direct and indirect resources usage and the pollutants produced. Gasoline fuel rom various sources, ethanol fuel from various sources, cars, tractors, trucks, solar panels, paper, hair pin, rice, corn, apricots, they are all found in those databases and we are also adding more items after their accounting is approved.

We consider each stage, for example in the production of conventional gasoline, we have accounted all the inputs between any stages of production. How much energy, water, was spent and how much pollutants produced, how much space all the associated trashes will add to the land fills, starting from exploration, the drilling, the pumping, transporting, refining, distribution, until they are used by machines. All the refiniries, storage containers, machines and equipments used, how much energy was used to build them and all the other associated inputs and pollutant outputs have been accounted for. Different types of technologies will have associated resources used and environmental output. the inputs and outputs are often expressed on per unit usage, like how many total grams of CO2 were used per mile usage of driving a car. It is not only the production of the gasoline that is to be accounted for, but all the other resources in producing the car divided by its lifetime to express in the same units on per mile usage.

I can give you reference where to download such databases that have been scrutinized not by one or two but a plethora of dedicated scientists. And we are contributing to continually refine these databases as more technologies and their actual measurements are taken and validated.

Thus saying all of my percentages were gross oversimplification. But there's the actual data of ethanol from corn, California Refined conventional gasoline, diesel, and you can download them from the EcoSpold, EcoInvent, and GREET databases.

Very impressive Joe.

Me Too Benny! Joe, you obviously know energy!

How do you get energy from "hair pin"???

Forget about the hair pin Harvey, there is new ethanol in town. Move over corn, and here comes citrus peels!

Follow the alcohol this way: link