Letters

Nov. 10, 2003
In your OGJ, Oct. 6, 2003, p. 19 issue, Cal Hodge pays special attention to ethanol's supposed negative net energy balance ("Ethanol's energy contribution: real or imagined?).

Ethanol's net energy balance

In your OGJ, Oct. 6, 2003, p. 19 issue, Cal Hodge pays special attention to ethanol's supposed negative net energy balance ("Ethanol's energy contribution: real or imagined?). Although I don't find his analysis particularly convincing, it really doesn't matter—a negative net energy balance, by itself, means very little. If negative net energy balances were bad, we'd never consider excellent fuels such as petroleum gasoline, petroleum diesel, Fischer-Tropsch diesel, electricity, hydrogen from natural gas, or virtually any processed fuel, since virtually all have negative energy balances because of thermodynamic laws. Interestingly, Mr. Hodge, an MTBE proponent, failed to mention that MTBE itself has a negative energy balance. The only reason that ethanol's balance is anywhere near positive is that it benefits from lots of solar energy, which is considered "free" in a net energy analysis.

What does matter is cost and environmental impact, and net energy balance analysis is one tool that helps us to estimate these. For example, Argonne National Laboratory's analysis of corn-based ethanol concludes that its full fuel cycle greenhouse gas (GHG) emissions are less than those of gasoline—so its use as a gasoline substitute would be beneficial from the standpoint of climate change. If we can produce the ethanol from cellulosic materials, the GHG benefit would be very large. Of course, GHG emissions are but one of many factors that must be evaluated to reach any rational conclusion about the overall value of ethanol use in vehicles. But let's focus on the things that count.

These views are the author's, and not necessarily his employer's.

Steven Plotkin
Argonne National Laboratory
Washington, DC

More Hubbert's Peak

M. King Hubbert wrote part of a gloomy 1975 report of the US National Academy of Sciences, which foresaw the early depletion of all resources, including oil. This report provided the intellectual underpinnings for President Jimmy Carter's crash program of synfuels.

I pointed to shortcomings in the methodology in a short Letter to Science magazine (May 2, 1975, p. 401). I would be delighted if you could reprint this letter, since everything there is still valid today.

(Editor's note: The reprinted Science magazine letter follows)

Hubbert's Peak—Why?

You don't have to be a rocket scientist to figure out that there must be a peak in oil production—somewhere. After all, we started with zero production in the 19th century and—for sure—we will reach zero again sometime in the future. So the real trick is to predict when the peak will occur.

Much is made of the fact that M. King Hubbert, my erstwhile colleague in the Department of the Interior, predicted that such a peak for US production would happen around 1970—and that it did. Was this prediction based on insightful methodology? In which case, the Hubbert approach might also predict the peak year for world oil production. Colin Campbell and others share this belief. Ken Deffeyes even proposed a money bet for the peak to occur between 2004 and 2008.

Or was Hubbert's predictive success just a fluke—as seems likely. Let's see now. He took a number for total recovered oil and then fitted a bell curve whose area matched this number. But in the years before 1970 the Texas Railroad Commission set production quotas—to keep the price from collapsing or to practice conservation; it depends on your point of view. In any case, if they had not done so, the production peak would have been reached well before 1970 to satisfy the rising demand. But as soon as they ran out of spare production capacity and the quotas disappeared, the price started to rise—and that's when the Organization of Petroleum Exporting Countries exerted market power. During 1970-73 the world price then quadrupled to $12/bbl, the lifting cost of the US marginal producer. This transition was accelerated by the Arab oil embargo of October 1973.

This might explain the rise in US production up till 1970. But why did production drop since then? If the US had been the only producer in the world, the price would have continued to rise and the peak would have been reached much later. But OPEC has managed to keep the price more or less constant. And with a constant world price, US oil output, based on high-cost production, must inevitably decline.

S. Fred Singer
Arlington, Va.