Friday, May 25, 2007

Three Cornered Ghost

Gas, oil and coal form ghostly triangles in a number of ways. Our necromancy for one affects our necromancy for the other two: as gas becomes harder to come by, we turn to coal, for example. Or, when the body count begins to rise in our efforts to secure oil supplies, thoughts again turn to coal.

There is one particular triangle that turns out to be very important and that is the shape of an oil fields production with time. When an oil field is discovered, its production increases as more and more wells are drilled to draw it out of its grave. But once one of these wells run dry, the rest soon follow and there a steep drop in production. This triangular shape forms the basis for an analysis which looks at the rate of discovery of oil fields to estimate future production integrated over all oil fields. Oil is the easiest (and most dangerous) of the three to transport so people generally look at the world supply in this case while local supplies are more important for the other two. The analysis of oil production is made difficult because oil companies tend to lie about what they have discovered to boost their share prices but it is thought that oil production has already reached its apex or soon will.

It is usually assumed that, at some expense, declining gas and oil supplies can be replaced by coal because there are centuries of reserves. Even George Monbiot, in his new book Heat makes this assumption though perhaps his goal of reducing energy use is reason enough to leave this unexamined. A new look at the available data throws this assumption into question. Using the same sort of predictive modeling that has been applied oil production, it could be that coal production will peak in fifteen years.

Richard Heinberg of the Post Carbon Institute gives an interesting summary and analysis of the report. Here, I want to look at its very suprising contention that coal production in the US has already peaked in terms of energy extracted.

Coal comes in various grades. The best, anthracite, contains the most energy and is the cleanest burning. Advertisers, attempting to displace a cleaner, more efficient and pleasant alternative used to say that a lady's dress would stay ghost white on a train ride through New York because the engine burned anthracite. Advertising is usually needed to get people to choose something so deadly.

Until recently the cost of coal in terms of mining deaths in the US has been declining owing to better regulation and, while the total mining deaths since 1900 still out number the oil war deaths, the numbers are becoming comparable. Grades of coal below anthracite are progressively softer and yield less energy. As can be seen in the last link, the number of miners has been growing recently (figures in include office workers) and, as might be expected, the amount of coal produced is also increasing, but what the German report says is that the amount of energy being produced from all this dangerous effort is going down. This is because softer coal is replacing harder coal. So, getting the number of mining deaths declining again is going to take a great deal of effort since more and more miners will be needed to mine more and more coal of lesser quality to just keep even on energy production.

It is not clear that the analysis applied to oil production works in just the same way for coal. In terms of energy extraction, the US is past its peak production for oil (1970s), gas (this decade) and now coal. But, whereas no amount extra fiddling gets an oil field to produce what is once did after it starts to decline, extra money could make coal production increase. We just have to pay more miners for less energy per miner as we have already begun to do. But, one thing looks to be similar, the cost in money should increase for coal just as it has for gas and schemes to replace gas or oil with coal will be more expensive as the trend towards less productive mining continues.

The triangles of ghost energy lead inevitably to disappointment. The shape of real energy is completely different. Striving is rewarded evermore richly as we hone our skills in participating in it. Costs come down as our efforts increase, reaching a sustainable plateau that is not set by some fixed lower limit on cost per unit energy but rather by what we will find satisfactory.

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