Well, at least we have enough coal

There is a number range that keeps getting batted around in the world of fossil fuels. That range is 200 to 300 years, referring to the amount of coal we have left. It is almost a throwaway line, a truism. Global warming stands between us and a cheerful enjoyment of these fossilized riches, but it is a comforting thought, nevertheless. In fact, it might only be a thought and not a reality.

By analogy, imagine that you are scuba diving, and that you have an air tank with an hour’s supply in it. It is useful to know that you have an hour’s worth of air in terms of planning your dive. Now imagine that there is a malfunction in the regulator so that you can only get 50 seconds worth of air in a minute. Life underwater just got a bit edgy. Now imagine that the malfunction progresses, from 5/6 of your need to 2/3, to ½. Suddenly that hour’s worth of air becomes an unimportant concept compared to how much is coming out of the mouthpiece right now.

This is the same concept as peak energy, whether that energy is in the form of oil, natural gas, coal, or uranium. What matters is that we need X billion barrels, cubic feet, or tons this year, and if we get less than X, the price goes up and people do without. How many years worth are left in the ground becomes a secondary matter.

I recently heard an offhand mention on The Oil Drum that David Hughes, a chief energy geologist for Geological Survey of Canada said that the U.S. had passed peak coal energy production. (Canadian coal production has been in steep decline for over a decade) I decided to look at the numbers.

The US Energy Information Agency provides figures for coal production in the U.S. When I looked at the tables I found that overall coal production in tons is still rising at 1.133 billion in 2006, about 1% up since 2001. However, the mix of coal has changed. There are four categories of coal:

Anthracite – hard, shiny, and high energy, averaging 25 million BTUs per ton
Bituminous – softer, more crumbly, averaging 24 million BTU’s per ton
Sub-Bituminous – less dense, averaging 18 million BTUs per ton
Lignite – brown, soft, light, averaging 13 million BTUs per ton

A BTU, by the way, is the energy necessary to raise the temperature of one pound of water by one degree Fahrenheit. A useful approximation is the energy obtained by burning one wooden matchstick.

Anthracite and lignite production are a small fraction of the total. The production of bituminous has been falling since about 1990. The production of sub-bituminous is rising, accounting for the slight increase in overall production. So, there is less of the good stuff and more of the mediocre stuff, with production of the really good and really bad stuff flat and insignificant.

The upshot is that total coal production in terms of actual energy is down a little over 1% since 2001. (23.579 x 10^18 BTUs in 2001, 23.329 x 10^18 in 2005) The price per ton has doubled in that time, a fact that would have made headlines if oil weren’t doing the same thing. And yet, it is slightly worse than that.

It takes some energy to dig coal out of the ground, and the trend with any mined resource is to get the easy stuff first. Back in the 1950s it took the energy equivalent of one ton of coal to extract 70 tons. By the 1970s that one ton equivalent extracted only 30 tons. Ok, so we went from a 1.25% energy cost of extraction to a 3.33% energy cost. Minimal, but a doubling in 20 years. More recent energy return on investment (EROI) figures are around 8 to 10. So, that one percent drop in total coal energy production has to be worsened by perhaps ten more percentage points to get the net useful energy from all that tonnage. Some energy analysts are following the EROI curve and predicting that U.S. coal will reach 1:1 in the next few decades, rendering the rest of the 300-year supply essentially useless as an energy source.

At best, we are on a coal production plateau, one that could persist for some time. We are definitely on a net coal energy downslope, one that can only get worse with time. Even if the slope is shallow, it comes during an awkward period. Demand for energy, especially electrical energy, is increasing as our supply of natural gas, the other premier power plant fuel, is declining. Coal fired plants produce more greenhouse gas and other pollutants per kilowatt-hour than natural gas. It is another sign for us to accelerate towards a more energy efficient economy and more rapid development of renewable energy.

Comments

[Robby]

All right H, here are some numbers I would like to see in a future blog:
Global energy consumption increase, ten year trend.
Global renewable energy production trend
Renewables as a percentage of total consumption trend
The numbers extrapolated out to say 2050
Best, realistic case scenario for an all out
push for conservation and renewables.
My guess is that even under the best case scenario we are still going to use a lot of coal. Which brings me to the question i have about this current post, is there a clean way to get the energy out of this coal?
Robby

[Jim Buckley]

Yes, there is certainly an ingrained myth regarding coal. A professor Bartlett, at Global Public Media, also seeks to expose that myth by explaining how projections are often based on current levels of use. While current levels of energy use are going to double in 20 years or so due primarily to growth in China and India, bringing about an impossible situation. (as well as, as you say, extraction will become more inefficient). Bartlett's article is at http://globalpublicmedia.com/transcripts/645
It is urgent that renewable energy comes onto the market quickly. Germany is doing that now, and may reach 50% of their energy needs with renewables in 20 years. Hermann Scheer, author of the German Renewable Energy Policy has said, (in a TUC radio interview), “The idea was and is to introduce renewable energy very fast and in ever larger numbers as a substitute for conventional energy. For this the legal framework was created that would guarantee free access to the grid by the small energy suppliers. We are now supplying 10% of Germany’s energy needs, and hope to replace conventional sources in 50 years, and we have an outreach program to developing countries to do the same. It is a decentralized system because it is an energy supplied by nature, and is everywhere. This is in contrast to the huge infrastructure of oil fields, tankers, pipelines, and dominating economic methods needed to distribute fossil fuels”. The advantage of the German system regarding solar is the emphasis on a place and plug-in grid tied system, omitting almost completely the untenable maintenance requirements of a battery operated system, which is still prevalent in the US.

[Heretic]

Hi Robby, Jim,

Thanks for writing in. Robby - An interesting topic: just how much can we actually accomplish? My belief is that we will start with conservation (turning down the thermostat), then efficiency (insulate), then technology (better furnace or solar), basically in order of cost. We will do this amidst the sound of whining and angry accusations. Even if renewables simply explode, we still will need decades to make a dent in our present wasteful ways. Europeans use half the energy per capita - that's where we are going.

Jim,

Thanks for the link. China and India are going to drive off a cliff. China is trying to accommodate its urbanizing, wealth seeking population by expanding foreign trade, and energy use with that. There just isn't enough oil, coal, or anything to maintain that for much longer. The Chinese are trying hard for efficiency and renewable energy, but the horse won't pull it.

MH