After four decades of fully authorized, commercial, even subsidized attempts to develop oil shale into a usable liquid fuel, no one has ever been able to make it economically feasible. Part of the reason for that is that it’s not even really oil—it’s kerogen, an immature precursor to oil. Kerogen is a solid, like a low-grade, high-ash coal.

The most ambitious oil shale project in the country is a pilot project in northwest Colorado operated by Shell. Their plan is to drill several hundred holes into a football-sized plot of land, into which heating elements are inserted. They will heat up the "pay zone" of hydrocarbons, which is often buried 2000-4000 feet deep, to temperatures up to 700 degrees F, and keep it there for three to four years in order to cook the kerogen into a liquid.. That takes a great deal of energy input.

In order to keep the heated zone from leaking oil into the surrounding water table, a "freeze wall" is built around it, which will use even more energy to freeze the ground with giant chillers.

The net energy of this process isn’t yet known, but it’s so energy-intensive that we’re willing to bet this technology is unlikely to ever produce more than a modest flow (though perhaps a very long-lived one) of extremely expensive synthetic oil.

ASPO’s (and Post Carbon Institute Board member) Randy Udall puts it this way: "Suppose you owned $100 million dollars, but the bank would only allow you to withdraw $100,000/year. You would be rich…sort of."