Many energy experts are looking to clean-burning coal as an alternative to crude. If that works out, the price of oil could come down as the US and other big countries like China move to the old source of energy that is becoming attractive again.

But the cost of getting clear-coal to market may be too high for it to be practical. According to The New York Times, "the failure to start building, testing, tweaking and perfecting carbon capture and storage means that developing the technology may come too late to make coal compatible with limiting global warming."

Do those problems really rule coal out as a big source of energy? Maybe not. The decisions to fight dependence on oil may involve some very hard compromises. Oil-based energy hurts the environment. Ethanol drives up corn prices at a time when commodity inflation is already pushing food prices much higher.Governments and individuals are going to have to decide whether cutting the need for oil is worth additional pollution or whether $5 gas is a better way forward.

The same argument is beginning to move to nuclear power. There are fears that this source of energy may be too dangerous because nuclear power plants sometimes have dangerous leaks. But nuclear can provide a huge portion of the electricity needs of many nations, as France has already shown.

With oil at $120 or more, energy consumers can't have it both ways. The days of cheap energy are gone, and the age of cheap, clean energy may be years away. In between, the trade-offs are ugly.

Douglas A. McIntyre is an editor at 247wallst.com.