Sunday, June 07, 2009

Lessons from Dr. Evil

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Have you noticed that the numbers we use in daily conversation keep getting bigger and bigger? When I was young my father pointed out to me that a family who had one million dollars could live off the interest alone, and would have a tough time spending it all. While that was certainly true at the time, the value of a million dollars is not what it used to be. Here’s a clip of one of my favorite movie villains to help illustrate my point (you’ll have to listen to the podcast on this page to hear the audio clip of Dr. Evil).

Even Dr. Evil had trouble comprehending the size of a billion dollars, but what hundreds of billions or even a trillion? We hear and read those numbers in the news and in conversation, but what do they really mean? It’s easy to understand the number of zeros that make them different, but that still be pretty abstract. I contend that many of us really don’t comprehend how large those numbers are when it comes to measuring things in the real world. We need visual or mental references to help us understand the scale of such large quantities.

Let’s use electrical power as an example. The base unit of measure for electrical power is the Watt, but what is the difference between a watt, a KW, a MW, and a GW?

  • 1 watt will barely power a small incandescent light bulb like a bathroom night light.
  • 1 kilowatt (1,000 watts) is equal ~ 1.3 HP, about the same energy output as a small lawn mower engine. The average household in the USA uses about 1 KW of electricity on an on-going basis if averaged over an entire year.
  • 1 Megawatt (1 million watts) is enough electricity to power a small town. Large diesel locomotive engines generate in the 3 to 5 MW range.
  • 1 Gigawatt (1 billion watts) is the size of a large central station power plant, and is enough energy to power about 1 million homes.
  • 1 Terawatt (1 trillion watts) is energy on a continental scale. The total worldwide electricity demand is about 15 TW.

Now to the real point of this show – I want to speak to you about the carbon capture and storage, and the scale of the challenge this concept presents. To put it bluntly, the scale is bigger than huge, it’s even bigger than enormous. The amount of carbon dioxide gas released by coal and natural gas plants is planetary in scale. Let me describe what I mean by that.

The US DOE estimates that US and Canada stationary power plants produce 3.8 billion tones of CO2 per year,and the world wide total is 33 billion tones. But really – how big is that? Here’s the answer: At standard temperature and pressure, one ton of CO2 occupies 556 cubic meters. It’s still a little tough to visualize how much material that is. Well, the International Carbon Bank and Exchange did some calculations for us. The USA’s emissions of CO2 each year would cover every square foot of the continental Unites States to a depth of 1 foot.

Let me repeat that so it will sink in…. burning of fossil fuels is producing enough CO2 waste to blanket the entire continental United States to a depth of one foot. As I said, the problem is one of planetary scale. From a very common sense point of view, the challenge of compressing that enormous volume of gas or converting it to solid or liquid, then storing it in a way that it can not escape for several hundred years is simply not doable. I am not being pessimistic, just practical. It is a huge waste of time and resources to embark on a path to even attempt to capture and store CO2 when there is another solution: don’t create it to begin with!

Nuclear energy is an already tried and true technology that produces virtually no CO2. Anti-nuclear people will tell you that nuclear energy does create CO2 because of the energy used in fabricating fuel, manufacturing the building materials, and plant construction. Yes, that’s true, but it is a very small amount by comparison. Plus, if we ran our electrical grid on nuclear energy then most of that energy would be generated without emitting greenhouse gas.

Since I’m talking about the scale of waste products produced, I have to mention the mountains of solid waste produced by every coal plant every year. A typical large coal power plant burns the equivalent of a two-mile long train of coal every day! That’s a 700 mile long train every year. Since up to 10% of that original coal ends up as solid waste, every coal plant disposes of the equivalent of a 70 mile long train of toxic ash every year.

The world uses about 6 billion tones of coal each year. That’s a pile of coal one mile high and 2.3 miles across! That same ratio we generate 600,000,000 tones (600 million tones of solid coal waste every year. That’s a pile of waste more than 500 feet high, higher than three statues of liberty stacked one on top of the other!

By comparison, all the nuclear plants in the USA create only 2,000 tones per year of used fuel. If you took all of the used fuel from all of the commercial reactors that have been generating 20% of the USA’s electricity for the last forty years it would all fit on one football field to a depth of only seven meters. That used nuclear fuel is in the form of stable ceramic material encased in corrosion resistant metal, and can be very easily and safely stored until it is recycled or processed to remove valuable materials contained within.

The problem of trying to capture and store such an enormous volume of CO2 from coal power plants is practically unimaginable. Even if we are able to capture and store all that pressurized gas, we’d still have to keep it contained for more than 100 years. On the opposite end of the spectrum, the amount of used fuel generated by nuclear plants is minuscule by comparison and can be easily stored and monitored. Its common sense, but sometimes the truth is obscured by the numbers.

Next time you hear someone talking about spending millions or billions of dollars on carbon capture and storage research projects in hope of enabling us to keep burning coal, ask yourself, “I wonder if they’ve ever listened to Dr. Evil.”