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By Robert Rapier on Jun 17, 2007 with no responses

Coal and Ethanol

A Lightbulb Uses a Lot of Coal

Just a very quick post today while still on vacation in the U.S.

I was browsing around the other day, and I ran across this:

How much coal is required to run a 100-watt light bulb 24 hours a day for a year?

You can pop over there for the details, but I was shocked at the result:

714 pounds of coal, 5 pounds of sulfur dioxide, 5.1 pounds of NOx, and 1852 pounds of CO2 – for 1 light bulb. That just blows my mind. Sometimes I will leave my computer on overnight, rationalizing the decision by thinking “It only uses about as much electricity as a light bulb.” I have to adjust my thinking.

Robert Bryce on Ethanol

I have missed out on a lot of good commentary on the insanity going on in congress right now with this energy bill, but Robert Bryce – whose positions on energy issues are almost all identical to my own – summed it up well in Slate:

The Great Corn Con

Thirty-six billion gallons of ethanol a year sounds like a lot, but it’s only 2.34 million barrels per day. And given ethanol’s lower heat content—about two-thirds that of gasoline—the effective production would be equivalent to 1.54 million barrels of oil per day. The United States uses nearly 21 million barrels of oil per day, of which 12.54 million barrels are imported. Thus, even if American ethanol producers can miraculously achieve the Senate’s goal of 36 billion gallons per year by 2022, they will be producing the equivalent of just 7.4 percent of America’s total current oil needs and just 12.2 percent of its imports. That quantity of ethanol will not take America very far toward the oft-repeated goal of energy independence.

I would add to this that this calculation does not back out the fossil fuels that went into making the ethanol. Since it takes 1.0 BTUs of fossil fuel to make (arguably) 1.3 BTUs of ethanol and animal feed, it will take 36/1.3, or almost 28 billion gallons of ethanol equivalent to produce the 36 billion gallons. Therefore, the net is 8 billion gallons – less than 2% of our total oil usage. That is what is actually displaced if 36 billion gallons of ethanol is produced. Insanity.

Of course some people correctly point out that we have lots of coal, and coal-fired boilers can be used to fuel the ethanol plants. And of course this is true, but it’s going to take a lot more coal than it would take to run a million light bulbs.