What I'd really like to know about the whole process is whether anyone has defined at what point it becomes more economic for the power plants that need to be constructed to heat the rocks to just sell their electricity on to the grid.

I had a chance to ask a couple of questions of Shell engineers following a presentation they made at Colorado School of Mines. Back of the envelope, a million barrel per day operation would require electrical power close to the total amount currently generated in Colorado. Utah and Wyoming are already net electricity exporters; unless someone builds new transmission capacity to California (and such plans are proposed, from time to time), they would just be trying to compete with existing coal- and gas-fired generating capacity.

I also got to ask "If you put that amount of energy into oil shale, and you put the same amount into coal-to-liquids, which would generate more liquid fuel?" They said that their current systems analysis suggested that coal-to-liquids would produce more. As a Colorado resident, I have to say that I'll be happy to see them invest the money in coal-to-liquids in southern Illinois instead of oil shale in northwest Colorado. Between the Ohio and Mississippi rivers, I assume they've got plenty of water to support it.