Study says ethanol not worth the energy: This is a couple of weeks old, but still a bummer of a deal for the Midwest. Ethanol is kind of the Darling of the Dakotas given all the corn around here. But, sadly, it seems as though it’s not a terribly efficient way to produce energy.
But researchers […] it takes 29% more fossil energy to turn corn into ethanol than the amount of fuel the process produces. For switch grass, a warm weather perennial grass found in the Great Plains and eastern North America United States, it takes 45% more energy and for wood, 57%.
It takes 27% more energy to turn soybeans into biodiesel fuel and more than double the energy produced is needed to do the same to sunflower plants, the study found.
So, the bottom line is that we’re losing power when we try to make these alternative fuels. But aren’t we losing power in general? Don’t we lose energy when we convert oil into gasoline?
Believe it or not, but this goes back to to the quasi-religious discussion we had about entropy and thermodynamics. There’s no way to have a perfect transfer of energy from one medium to another — there’s always going to be waste and loss. There just seems to be more loss in some mediums than others.
Wikipedia calls it “Energy Balance”:
When comparing fuel production, energy balance is the difference between the energy produced by a 1 kg of the fuel (i.e. biodiesel, petroleum, uranium ) and the energy necessary to produce it ( extraction (e.g. drilling or cultivation of energetic plants), transportation, refining etc).
The article on fuel alcohol has a good discussion on the energy balance of the various flavors.
Ethanol has a positive energy balance, meaning the ethanol yields more energy than it takes to produce it. It is an efficient fuel made through an efficient process. […] It takes less than 35,000 BTUs of energy to turn corn into ethanol, while the ethanol offers at least 77,000 BTUs of energy. Ethanol’s energy balance is clearly positive. […]
One faulty, outdated study shows ethanol’s net energy balance to be negative. That research uses fundamentally flawed, decades old data that is not valid considering today’s efficiencies in agriculture and in ethanol production.
So who’s right? Depends on who’s spinning the issue, I suppose.