(This is Part 26 of a series. Go back to Part 25.)
Let's consider now some of the alternate fuels that might be used to replace the diminishing resource of oil:
Natural Gas. It's an obvious candidate. It's energy-dense, versatile and burns cleaner than any other fossil fuel. And its EROEI is attractive.
The biggest drawback of natural gas is that it is also a non-renewable, diminishing resource. From 1977 to 1987 9,000 new gas wells were found in the U.S.; in the next decade, 1987 to 1997, only 2,500 new wells could be found—this despite strenuous efforts by the industry.
The number of new gas drilling rigs in the Gulf of Mexico increased by 40% from 1996 to 2000, yet gas production stayed flat. That is largely because the new fields tend to be smaller; moreover, new technology drains them faster. As Richard Heinberg says, "New gas wells average a 56% depletion rate in the first year of production."
In other words, the North American gas industry is an industry running faster and faster to stay in place. Mexico has cut off exports. Canada is having to drill more and more wells each year to hold its production steady. How long can that keep up?
Unlike oil, gas wells tend to deplete quickly, so that the worldwide gas production curve after its peak could quite possibly see a precipitous drop instead of a slow decline.
There are large reserves of gas in the Middle East, but shipping the gas is a problem. Gas must be liquified and maintained at minus 260 degrees F. to be shipped by boat; moreover, most of the shipping available for liquified natural gas (LNG) is tied up under long-term contract to Japan, Korea and Taiwan.
And lest we forget, burning natural gas does release large amounts of CO2 into the atmosphere. And it's a finite, non-renewable, depleting resource. All things considered, the industrialised world cannot base its future economy on natural gas.
Coal. Hey, what about coal? There are enough reserves of coal to last hundreds of years.
The problem with coal is two-fold. First of all, it is an extremely dirty fuel. The burning of coal not only spews tremendous amounts of CO2—much more than oil—into the atmosphere, but it also releases a real witches brew of toxins such as sulpher oxides (which cause acid rain).
The second problem with coal is that it has a low—and falling—EROEI. Coal has a relatively low energy density to begin with, and the mining of coal takes a great deal of energy in itself.
And the low energy yield of coal is declining further as the easy reserves are depleted and coal mining becomes more energy-intensive. Really, coal has only been viable at all because there's been lots of cheap oil to provide the energy to extract it. Considering its extreme pollution and low and declining net energy, coal is a poor candidate for powering the world economy in the future.
Shale oil, tar sands, et al. These have the same problems as coal, only even more so. When we consider the process of extracting oil from them, they are even more polluting than coal and provide even less net energy. In spite of the hype, not a viable prospect.
(This is the end of Part 26. Go to Part 27.)
—jim sloman, 10.22.04 for Nov 19
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