Chosen by Asker

The best way to evaluate an energy crop is to compare energy output to energy input. Sugar cane is a poor option for the US because the climate isn't tropical, and so yields per acre are low (hence low ethanol output). (side note: the domestic sugar industry is only competitive because of subsidies and tariffs.) Corn on the other hand, has reasonable output, but requires a lot of energy inputs to produce. Natural gas is used to make fertilizer, which corn needs a lot of, and diesel is used to till, plant, and harvest. Plus, even though feed corn isn't eaten by people, it is grown on land that could be used for other crops, and increased demand for feed corn also puts upward pressure on meat and dairy prices. A better option for the US are fast-growing grasses such as switchgrass or miscanthus. These are perennial so a single planting can be harvested for 10-15 years without tillage. They also require little to no fertilizer. The challenge is that they are composed of cellulose which needs to broken down into sugars before it can be fermented to ethanol. The technology for doing this has been proven to work, but needs some optimization to make it economical (high oil prices also help make it competitive). The much higher yield of these crops, and the fact that they can be grown on marginal lands means that they have the potential to replace most of our transportation fuel with little impact on food prices. P.S. Don't listen to any web-hype about algae, I've read much of the scientific literature, and most numbers you see on the internet are dramatically overstated, while the difficulties are ignored.

by Adam

3 months ago

Asker's Rating: 

No.. Even though Brazil is a huge country, their economy is a small fraction the size of the US economy (1.65 trillion in 2006 vs 13.1 trillion). No crop can supply the US economy with the energy it needs, as the sole source of energy. Sugar cane could supplement things, and would be a better idea than wasting corn. But oil is the way to go, and there is tons of it. We lack the will to go after what we have, we lack the will to fight those who stand in the way of getting it.

by curtisports2- 3 months ago

Yes. Brazil has the climate for producing sugar cane. Hence they can use it to distill ethanol. It is efficient because the process for making ethanol involves distilling sugars. With other substances you first have to extract the starches then convert them to sugars. In climates that can't grow substantial amounts of sugar plants, we must use other agricultural/renewable substances. There are a few sugar plantations in the south but for those existing plantations to sell their product to make ethanol wouldn't be profitable. Ethanol could be made from many substances but the process isn't cheap so the distillers need "value added by-products" The US has a better climate for corn & that is why we must use what is readily available to us. The UK has a better climate for wheat or barley. In the US the production of corn-to-ethanol also produces some valuable by-products. (ie;distillers garins, corn oil) The corn used for ethanol production is not fit for human consumption. It is called "field corn" Only the starches from the 'field corn' are are used for ethanol. The remaining 'grain' is used as a high protein feed for livestock. and the corn oil is also removed by the ethanol production process. So while the actual production of fuel_from_sugarcane is more efficient...the by-products that are created by fuel_from_corn make it also an efficient & value-added source

by Eleanor- 3 months ago