Dear Umbra,

Lately I’ve been struggling with the idea of ethanol as a green fuel. It seems to be getting a lot of attention in the government and media, and it is being touted as the answer to this country’s petroleum woes (see GM’s “Live Green, Go Yellow” campaign). But from what I’ve read, ethanol production has and will likely continue to have a negative energy balance and its carbon dioxide emissions are comparable to gasoline’s. Can ethanol really be the answer to our problems?

Ben Van Lear
Merritt Island, Fla.

Dearest Ben,

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Probably not. It’s unlikely that an automotive fuel is one of the big answers to our problems. Less driving, friend, and fewer cars on the road. Fewer roads, in fact. When I am dictator, trains will once again run free across the prairies.

Feeling lost in a sea of corn-fusion?

Photo: iStockphoto

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Ethanol is an interesting fuel, though, with some potential to transform our big problem into less of a problem. Grist’s Muckraker pieces on ethanol politics can give you the skinny on government and industry attention, so why don’t I back up and go to the rudiments for all dearest readers.

Apparently the first cute little internal combustion engines used alcohol fuels, and ethanol is indeed alcohol, ethyl alcohol, made from fermented plants. Corn is the common feedstock for ethanol in the United States. It is basically ground into a mash, fermented with yeast, and brewed up, in the same basic old process used to produce alcohol for drinking. Ethanol fuel has to be denatured at the tail end of the manufacturing process and rendered undrinkable or manufacturers would be subject to a beverage alcohol tax. Ethanol is already present in some gasoline fuels, in a 10 percent blend (“E10”) that can run in any gasoline engine. Engines specifically designed to use higher amounts of ethanol — for example, “E85” is 85 percent ethanol, 15 percent gasoline — resist the corrosive effects of alcohol.

Conventionally grown corn is not the best ethanol feedstock from an environmental perspective because of petroleum crop inputs, monoculture agribusiness, poor energy balance (a shorthand way of saying that it takes more energy to make a fuel than is embodied in the resultant fuel itself), and other problems (see our piles o’ biofuels info for more details). For electoral incumbents and unpopular presidents, it’s a great ethanol feedstock.

Some environmental organizations do support ethanol development despite corn’s drawbacks, in hopes that corn ethanol infrastructure presages the eventual dominance of “cellulosic” ethanol. Cellulosic ethanol is made from other plant sources, hopefully whole plants grown and harvested sustainably or, alternatively, cellulose from waste feedstock. Cellulosic ethanol has a better energy balance than corn.

Ethanol is a green fuel, so I wouldn’t be too sick at the sight of the ethanol fueling stations that pop up over the next few decades. Your current car likely cannot run on E85, but you can buy U.S.-made E85 vehicles. Should you? Once again, I must refer you to our biofuels series for a more specific look at E85, its emissions properties, and, importantly, its political position with a government that loves to suck up to corn agribusiness. (The Natural Resources Defense Council has also written excellent papers on the topic.) I don’t get an entire series worth of space — they like to contain me down here in the basement, where I merrily, privately, rant away.