Coal is temporary

by Milan on February 22, 2010

in Carbon capture and storage, Climate change, Coal mining, Power plants

For a moment, ignore all the environmental and climatic consequences of burning coal. Thought of only as an energy source, it is nonetheless demonstrably finite. Cambridge Professor (and Chief Scientific Adviser of the Department of Energy and Climate Change in the United Kingdom) David MacKay ran some of the math on the stuff:

In 2006, the coal consumption rate was 6.3 Gt per year. Comparing this with reserves of 1600 Gt of coal, people often say “there’s 250 years of coal left.” But if we assume “business as usual” implies a growing consumption, we get a different answer. If the growth rate of coal consumption were to continue at 2% per year (which gives a reasonable fit to the data from 1930 to 2000), then all the coal would be gone in 2096. If the growth rate is 3.4% per year (the growth rate over the last decade), the end of business-as-usual is coming before 2072. Not 250 years, but 60!

And, going back to climate change for a moment, we ought to remember that coal-fired power plants with carbon capture and storage equipment will use coal less efficiently to produce electricity. This is because some of the energy contains in the fuel will need to be dedicated to separating the carbon dioxide from the other flue gases (which, like air, are mostly nitrogen), then to pressurizing or liquefying the CO2, transporting it, and injecting it underground. It will also take energy to build the infrastructure necessary to perform these tasks.

Another thing to keep in mind is energy return on investment. Naturally, we started by exploiting the fossil fuel resources that were cheapest and easiest to extract: oil that literally shot up into the air when you sank a well. Now, we are in the world of difficult and expensive fossil fuels: those that take a lot of energy to get at and then process into usable fuels. We are certainly farther along when it comes to unconventional oil than when it comes to coal, but the same logic will eventually bite for the solid fuel. As such, the last portions of the global coal reserve will surely yield less energy for us than the first ones did, provided we don’t shift away from coal long before we get to those last reserves (which, because of climate change, we must).

As with all fossil fuels, coal has no long-term future. All of this is relevant because it illuminates the choice we are making. It’s not between a future that runs forever on coal (with climate change risks) and a future that runs on inexhaustible renewable forms of energy. It is between moving away from coal now, when it is still possible to save the climate, or doing so at the bitter end, once we have severely undermined the ability of the planet to support human life and prosperity. For everyone who isn’t the owner of a coal mine or a coal-fired power plant, this seems like a pretty easy choice.

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{ 5 comments… read them below or add one }

Jem Cooper February 23, 2010 at 4:15 am

You are absolutely right that coal will run out and that if we burn it all without capturing the carbon the planet will be a lot hotter. The free market will ensure that we switch to other energy sources as we run out, just as we switched to coal when trees ran out and fossil oil when tallow got short for lamps and candles.

But the free market will not ensure that we capture the carbon unless we put a system in place to make it and only my proposal to make fuel producers pay to capture an increasing proportion of the carbon in their products is actually workable. That was the essence of my first blog.

Milan February 23, 2010 at 8:13 am

I am generally supportive of mandating the use of CCS: telling companies that they cannot build any new coal-fired facilities unless they include carbon capture and storage.

That’s not an unproblematic outcome, however. There are still heaps of problems with coal-with-capture. Coal mining is dangerous, toxic work. There are the toxic emissions from coal burning, and the risks and contamination associated with coal ash.

We are really best off burying coal entirely as a power source, not in sixty or 100 years, but now. We have lots of better options.

Milan February 23, 2010 at 8:20 am

It is worth noting that no company has been willing to build a commercial CCS facility on its own dime. They are all demanding huge government support, liability disclaimers, loan guarantees, etc.

It may well be that the technology is just too expensive and risky to compete with alternatives, which would be fine by me if governments left it at that. Of course, given the huge coal reserves in the US and China, it could be useful to have CCS as one lower-carbon energy option.

Jem Cooper February 24, 2010 at 6:40 am

Of course nobody has built “a commercial CCS facility on its own dime”. It is always more expensive to build and operate a plant with carbon capture than one without. For the same reason mandating that new capacity should have carbon capture would not work. It would discourage utilities from building the new capacity needed to secure supply and even if that capacity were built it would not be able to compete; older dirty plants would be much cheaper to operate and would therefore be run preferentially.

You say “It may well be that the technology is just too expensive and risky to compete with alternatives”.

I say there are no alternatives. If you burn fossil fuel you need to capture the carbon dioxide to prevent a build up in the atmosphere. Energy saving, nuclear or renewables will not capture the carbon dioxide you make.

I dare say you would like to ban fossil fuel altogether, but in that case my proposal (see previous comment) to make fuel producers pay for carbon capture would no longer be operative, so why object to it.

Milan February 24, 2010 at 11:49 am

As you say, the alternative is not to burn fossil fuels.

The transition away from them is inevitable, whether it happens during the next 20-30 years or later when the fuels run out. There are all sorts of reasons to do it sooner, rather than later.

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