A new way to waste energy
Last week, the NYT‘s Andy Revkin blogged about a federal laboratory that says it can take atmospheric carbon dioxide and turn it into gasoline:
One selling point with Los Alamos’s “Green Freedom” concept, and similar ones, is that reusing the carbon atoms in the captured CO2 molecules as a fuel ingredient avoids the need to find huge repositories for the greenhouse gas.
The only problem with that exciting statement is that it is almost certainly not true, a point I will come back to.
Now the NYT has published an article on the subject that also overhypes the technology:
There is, however, a major caveat that explains why no one has built a carbon-dioxide-to-gasoline factory: it requires a great deal of energy.
To deal with that problem, the Los Alamos scientists say they have developed a number of innovations …
Even with those improvements, providing the energy to produce gasoline on a commercial scale — say, 750,000 gallons a day — would require a dedicated power plant, preferably a nuclear one, the scientists say.
Hmm. Let’s see.
Problem one: Motor gasoline consumption in this country is almost 400 million gallons a day. So we would need more than 500 nuclear power plants, just in this country … and just for gasoline (you’d have to more than double that to displace all the other petroleum products we consume, like diesel fuel). And that would probably require another five Yucca mountains just to store the waste, although I’m not sure the word “another” is right ’cause this country can’t even agree on one friggin’ storage site in the middle of nowhere.
Problem two: According to the Los Alamos “Green Freedom” overview (PDF), each 750,000-gallon-a-day plant (with accompanying nuclear reactor) costs $5 billion. So cutting under half of all petroleum use in this country would cost over $2.5 trillion (not counting this cost of uranium or disposal)!
This supposedly yields a gasoline price of $4.60 a gallon, though the authors say with a couple more technological breakthroughs that could drop to $3.40. How about if instead of assuming more breakthroughs, which hardly ever happen in the energy sector, we apply Romm’s Rule of Costs for Future Energy Sources.
Romm’s Rule says that for any new energy technology that is not yet commercial (and in this case we have a “concept” for which the patent was still pending in November), take the inventor’s highest projected cost and double it. Also, flip a coin, and if it comes up heads the technology will never be commercialized — think fusion. And that’s generous: in reality, if the coin comes up head or tails (i.e., doesn’t land and balance on its edge), it will probably never be commercialized. Remember the fuel cell was invented in 1839, and commercial fuel cells are just a tad more common than time machines. [Please note this rule does not apply to technologies that are already commercial.]
Problem three: Romm’s Rule of Energy Transformation. This rule, developed for analyzing hydrogen cars, says: You can probably make a sow’s ear from a silk purse if you try hard enough, but why would you do that? Zero-carbon electricity is arguably the most premium energy carrier you can make in a carbon-constrained world, in part because electric motors are so efficient. Electricity can directly run a motor to move your electric car or plug-in hybrid for under $1.00 a gallon, even using expensive nuclear power. You lose maybe one-fifth of the original electricity in the process. The entire Green Freedom process is so inefficient that it probably throws away more than three-fourths of the original nuclear power (if not much more). Basically, after spending all that money and wasting all that premier power, you are stuck with a low-grade (but conventional) fuel that has to be run through an inefficient gasoline motor. Why would you do that?
[Yes, we don’t quite yet have commercial plug ins, but they are straightforward extension of already commercial hybrids, we don’t need any technology breakthroughs, and multiple manufactures will almost certainly be selling them within three to five years. Electric vehicles will be common in other countries within the same time frame, as I’ve written. All of this will happen decades before “Green Freedom,” assuming it even proves feasible.]
Before coming to the last problem, let me complain about the NYT article, which, while skipping happily over the myriad problems with Green Freedom, bizarrely says of other alt fuels:
Hydrogen-powered cars emit no carbon dioxide, but producing hydrogen, by splitting water or some other chemical reaction, requires copious energy, and if that energy comes from coal-fired power plants, then the problem has not been solved. Hydrogen is also harder to store and move than gasoline and would require an overhaul of the world’s energy infrastructure.
Electric cars also push the carbon dioxide problem to the power plant. And electric cars have typically been limited to a range of tens of miles as opposed to the hundreds of miles that can be driven on a tank of gas.
Yes, if the energy comes from coal, neither hydrogen or electric cars make sense. But the same exact thing can be said of Green Freedom: It makes no sense if you use coal plants, but the NYT never mentions that fact. That’s why the Los Alamos inventors go the nuclear route. But if you can assume, say, 500 nuclear plants for Green Freedom, surely you can live with maybe 100 nukes for electric cars, which brings us to …
Problem four: We are going to need a vast quantity of zero-carbon electricity in this country just to reduce emissions 80 percent in the electricity sector while supporting population growth and increased living standards. In the very unlikely event we would build 500 nukes and five Yucca-sized storage sites (and find the necessary uranium, given that, presumably, ever other country is going to be doing the same thing) to make carbon-neutral gasoline, it is safe to say that’s all the nuclear power plants we will be building this century. So the electricity will have to come from renewable power and … yes, coal power with carbon capture and storage (CCS). And if we keep dawdling, we are going to overshoot the safe level of carbon dioxide concentrations, and then need to pull carbon out of the air and not burn it.
So Green Freedom does not save us from “the need to find huge repositories for the greenhouse gas.” If coal with CCS is practical and affordable, which strikes me as much more likely than Green Freedom achieving both of those goals, we are going to be doing as much CCS as we possibly can.
The scale of the climate solution is enormous — so great you would never contemplate it if the result of doing nothing were not so irreversibly catastrophic. That’s why, in spite of all these problems, in spite of the fact that it is exceedingly unlikely we would choose to use much Green Freedom by 2050 — even in the equally unlikely event it is actually feasible on a large-scale in that time — it probably deserves some exploratory funding. Although that assumes we have a president who triples federal clean-tech funding — I wouldn’t waste much money on it at current federal R&D levels. It certainly shouldn’t be hyped by the media. (Or anyone else: this means you, Roger Pielke, Jr.) It is certainly no silver bullet — it probably isn’t even one of the 10 silver bullets we need — but we can’t afford to ignore any solution that has even some microscopic chance of working.
[Tip o’ that hat to Earl K.]