Ethanol: Efficiency and Availability
In Brazil and a few other tropical countries, ethanol is fermented from sugar cane. This process is far less energy intensive (partly because human labour inputs are greater than in North America). It is reckoned to yield 3 times more energy than the fossil energy put into the crop and refining process. Also, sugar cane yields 5500-6800 litres of ethanol per hectare in Brazil; American corn yields 2800-3300 litres per hectare!
Another huge efficiency is the use of dried sugar cane stalks (bagasse) as fuel to separate (distil) the ethanol from the water. Most Brazilian ethanol refiners burn their bagasse in co-generation plants to generate electricity The waste heat then distils the alcohol. One such refinery produces 435 million litres of ethanol per year and puts 30 megawatts of surplus electricity (after supplying internal needs) into Brazil’s electricity grid! Many ethanol refiners in Brazil generate more electricity than they need. Derived from burning an agricultural waste, this electricity must be considered renewable – “green” energy!
It is estimated that converting the entire American corn harvest into ethanol would meet only 12% of current gasoline demand! Canadian Renewable Fuels (an ethanol producer) estimated that adding 10% ethanol to Canadian gasoline would require 20% of our total grain harvest (corn & wheat). However, the OECD reckons that level of ethanol would require 30% to 70% of our grain crop! It would make sense for America to import ethanol. Instead it imposes a $0.14 per litre (~12% of the current gasoline price) import duty on Brazilian ethanol, and puts a subsidy estimated at $0.25 – $0.40 per litre (combination of subsidies to corn farmers, to construction of ethanol refineries, and tax relief at the gas pump) on domestically produced ethanol. Together this makes it impossible for even Brazil’s ethanol (the world’s cheapest) to compete in the US market.