Robert Semple, Jr., who is the associate editor of the New York Times’ editorial board, has written an excellent review of the world energy situation and its future prospects. This appeared in the Times’ Opinion section under the title The End of Oil. The thesis of the article is that we will ultimately use up the world’s oil reserves and will have to turn to other energy resources in order to keep the transportation economy going. The uncertainty is in how long “ultimately” is. The oil pessimists, and I count myself among them having spent a few decades doing energy calculations, put “ultimately” in the next few decades. In fact, if Colin Campbell’s review of world oil resources is correct—and demand for oil continues to rise at current, or even accelerating rates—then oil prices will continue their upward climb and we will be out of oil for all practical (affordable ) purposes within 20 years.
If, as the oil optimists claim, there are a trillion more recoverable barrels of oil in the ground than the pessimists think, then we could have another 50 or 60 years of that form of energy plus, of course, accelerating global warming. However, I have uncovered scant evidence of that extra trillion barrels of oil. So I think I’ll remain on the side of the pessimists as a precautionary measure.
Then there’s the environmental impact of extracting this oil, aside from the global warming issues. For example, MIT’s December 2005/January 2006 issue of Technology Review has a photo essay on Canadian tar sands that might get your attention.
Please remember that we’re discussing liquid energy sources here, the kind needed to power transportation. What are some alternatives to oil? Batteries and electric motors that can run cars, for one. The problem there is that it is very hard to make lightweight, efficient, and inexpensive batteries. So most such applications today are hybrids that combine the batteries with a traditional engine fueled by guess what? There are also altered hybrids that can recharge the batteries by connecting them to a household power line at night. The household power is likely to be supplied by coal or natural gas. (By the way, natural gas may well be used up as a resource at about the same time as oil.)
Hydrogen-powered fuel cells are also the rage lately in energy circles. They are currently far more expensive than batteries and there is the nagging problem of the lack of stations where one can buy hydrogen for one’s car. Part of that infrastructure problem is the make or buy decision: should you produce the hydrogen at some central location and pipe it to the distribution stations or should you produce it on site from available raw materials? Currently the raw material in both cases is natural gas (which is mostly methane and for which a replacement will have to be found).
Nobel Prize winner George Olah, a former associate of mine at the University of Southern California, believes that methanol is the an answer. In addition to its ability to power vehicles methanol can be used to reduce carbon dioxide emissions. Methanol can be used to fuel typical reciprocating engines but Olah’s recommendation is that it be used in methanol (as opposed to hydrogen) fuel cells (fuel cells instead of, or in addition to, batteries).
So there are some promising alternatives to the transportation energy picture of today. These alternatives must be pursued to the point where they become economical. But they’re not enough. Realistically, we need to reduce our uses of transportation both to reduce the threats of global warming and to avoid running out of energy altogether.