Tuesday, April 10, 2007

Energy is Easy, the Environment is Hard

Keywords: Klaus Lackner; fossil fuel; carbon dioxide; climate change; carbon capture and sequestration; renewable energy; Net Zero Carbon Economy.

I spent the day reading and watching a video about energy. By far the most impressive experience was watching a superb lecture on the computer by Klaus Lackner, an engineer/physicist at Columbia University’s Earth Institute. I want to urge you to download and watch it. I was so fascinated that I watched it a second time, actually typing up a transcript of it as I watched.

Go to http://www.earthinstitute.columbia.edu/crosscutting/energy.html. Lackner shows up in several places on that page but what you want is on the right side of the page – where the heading is “Klaus Lackner: The Technology Key to Sustainability.” It’s a Real Video, 1 hour and 47 minutes long. You’ll do yourself a big favor by watching it. I cannot do it justice here, but I want to tell you something about it.

The value to me was in getting a better sense of proportion about the various problems facing us – the relative weight of the options and dangers. I’d like to pass some of those insights along here.

He notes that for sustainability, we have to have land, energy, water, food, and mineral resources – but is especially important because if we have lots of it, we can make up for shortages in the other things. For example, we could de-salinate water. raise plenty of food, separate minerals from the ore, and so on. If we keep the human population below 20 billion, we need not run out of any of these supplies, so long as we have abundant energy.

And we do have energy. Plenty of it. But we cannot use much of the form of energy that we’ve been using because it is wrecking the environment. Our serious problem is not energy; it’s . And the solution has to be technological. Fortunately, are nearly within our grasp. They don’t exist yet, but Lackner is optimistic that we can make them practicable.

We are not running out of , though we may be running out of oil and gas. There are 5,000 gigatons of cheap fuel, of which we are consuming only 6 gigatons a year. Moreover, the various fossil fuels are all fungible. They can all make synthetic gas, or electricity, or transportation fuel. Chemicals can be made from hydrocarbons. Energy in the year 2100 need not be more expensive than today.

The problem with all fossil fuels consists of the , of course – including the amount that has been emitted by human activities over the past 200 years.

Lackner cannot tell us where we’re going to be in 2050 because there are too many promising possibilities. Nevertheless, he can tell us what options are “non-solutions.” Energy efficiency or reduction will not do the trick, though they may help buy us a few years of leeway in reaching other solutions. Unfortunately, we will need a 97 percent reduction of carbon in the US, and efficiency will not suffice for that. We need a .

Nor can we succeed by growing trees. Or by a hydrogen economy, for hydrogen is only an energy carrier. It may work in the future, but at present it depends on electricity, which is produced mainly by coal or nuclear. Coal costs only one-fourth as much as nuclear, but that does not mean that solves our problem.

As for nuclear, Lackner is not enthusiastic, but nor does he suggest giving it up altogether yet. Fusion is still fifty years away. may be limited by the availability of uranium, but you could still get it from ocean water fairly cheaply, and the quantity there is virtually unlimited. Besides, breeder technology allows us to amplify uranium and to obtain thorium. However, the waste disposal issue is difficult, and the cost issue is impossible. Nuclear is far too expensive.

Turning to , Lackner holds out little prospect of getting sufficient energy from hydro, wind, tidal, or ocean thermal. I was surprised that he thought wind could not make up more than 20 percent of the total. In the longer term, solar is his preferred solution. It is unlimited. However it is still too expensive right now. Nevertheless, taking all these sources together, Lackner has no doubt that future generations will have abundant access to energy.

In the short term, there are definite challenges. We will probably need to go on using fossil fuels for decades — and from his point of view we may even opt to use such fuels as gasoline indefinitely if we also develop technologies for capturing and sequestering carbon from the air and from concentrated sources such as factory smokestacks.

The sequestration has to be perfected. Even a small leak can be disastrous, so the storage underground or under the sea bed has to be secure for millennia.

Lackner is looking into the use of such as magnesium silicates, which can be turned into . is an example; it would be mined, and there is plenty of it available. The resources far exceed the world’s fossil fuel supplies. It could be done right now but at present it is too expensive – even more expensive than nuclear power plants.

Lackner surprisingly proposes using a that runs on carbon. Theoretically its efficiency is 100%, whereas hydrogen’s efficiency is only 65% or 80%. Unfortunately, I did not completely understand his description of the carbon fuel cell idea, though he showed a drawing of it. (My grasp of chemistry is weak.)

The next phase of his argument is even more obscure to me: It’s about removing carbon dioxide from the air. He says that if you take any strong hydroxide (calcium or sodium hydroxide) and let it react with the air, it will turn into a carbonate. Would that be a practical thing to do on a global scale? To answer that, he compares the kinetic energy of a windmill to the chemical energy involved in capturing the CO2 from the wind. (I can’t imagine in what sense these two things are equivalent, but that’s my problem, not his.) If the wind is going six meters per second, a “window” about the size of a TV screen can capture 22 tons of CO2 per year. That is equivalent (so he says, and I believe him) to the energy created by a windmill 400 times greater in size. It would cost about 50 cents per ton of CO2. (I don’t understand this, so probably I’m not describing it correctly. If you have any scientific savvy I hope you can figure it out anyhow.)

Next he asks whether you’d rather run your car on hydrogen or , and then sequester the CO2 that it emits. Both gasoline and hydrogen come from fossil fuel. The difference is that with hydrogen you have to transport the CO2 to the place where you will dispose of it. With gasoline, on the other hand, you don’t have to transport it – you go ahead and emit it into the air. But then you have to go extract an equivalent amount of CO2 from the air someplace else – at the site where you will sequester it. You would compare the two costs – transporting the CO2 in the former case or extracting it from the air in the other case. At present, transporting the CO2 is far cheaper. However, Lackner’s ambition is to get the price of extraction down to $30 per ton. Even if it comes down to the $100 per ton range, it would probably favor air extraction. So he is not certain that we will want to give up fossil fuels even when we have the chance.

At present, anyway, it would be folly to try to close the fossil fuel option. It may even remain the main source of energy for decades to come.

Now, I did not expect to agree to any such idea. A few days ago I would have been horrified at the very thought of living indefinitely with fossil fuels. And even today I’m not sure. For one thing, he does not say anything here about preventing the emission of other pollutants or other greenhouse gases such as nitrogen. Beyond that, I certainly don’t know enough to have an opinion, but it seems to me that this is a promising idea.

Indeed, my complaint is that Lackner does not seem sufficiently bold! He’s thinking properly, as an engineer, about comparative costs for privately-owned businesses and homes. What struck me most about his idea, though, is that it can undo mistakes that have been made in the past, and which will otherwise destroy our future. We don’t have to go through global warming at all. We can go put up some of his carbon-capturing devices right now and reverse the climate change that has already taken place – reverting to the air that our pre-industrial ancestors enjoyed. We could start building those things next year. I think our governments should do this, not auto manufacturers or electrical power plants. Sure, they will have a duty too: to clean up an equivalent to the emissions they were generating from that point onward. But we don’t have to wait. Even if is an expensive technology right now, it must be cheap compared to the climatic disasters that are already beginning and which will surely get worse over time.

Hey, Professor Lackner! If you can do this already, please don’t be modest. Tell the world what you’ve figured out. Shout out your great news! I’ll be your publicity agent.



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