Several thoughts.....

Bob's dismissal of coal/CTL seems based on Sierra Club propoganda, not actual data. Coal is "dirty"? Well, farming is dirty, logging is dirty, mining is dirty.......hey folks, life is dirty. If we continue to try and minimize critical economic activities because of a false premise of a futuristic sterile society, we are not going to last long as a nation.

The fact is, based on today's fuel costs and cost projections (and assuming that pure market economics was the primary driver of managerial decision making), then a return to coal-fired reciprocating steam (with an inclusion of modern technologies) would be getting the most discussion. At 6% efficiency, coal fired steam beats modern diesels by a factor of 5 to 1 at today's fuel prices. Assuming we could achieve 12% efficiency with today's technologies (based on utility numbers), the ratio rises in favor of coal fired steam.

With modern power plant technologies and Porta's steam locomotive improvements applied to classic steam locomotion, the only real emission of note from coal fired steam would be carbon dioxide. All other emissions would be lower than the Tier 3 standards the EPA is applying to diesel engines. Non-volatiles could be easily collected in the ash pan and disposed of with proper care. Most rational people would gladly accept an increase in CO2 emissions in exchange for a reduction of the more nasty stuff being thrown into the air. Especially since we are in a period of global cooling.....(don't worry, won't go there!)

Synthetic diesel made from coal is a much cleaner product than either low sulfer #2 diesel or biodiesel. Because it is synthesized rather than transesterified (biodiesel) or hydrocracked (conventional diesel), it has almost no aromatics that cause particulation, it's sulfer content is less than 1 part per million, and nitrous oxides are much less than biodiesel. As for the clean up of the removed elements like mercury, ash, sulfer, et al, isn't it better to have that stuff cleaned out at the production facility rather than trying to remove it from the stacks of diesel motive power?

I'll go out on a limb and state for the record that we will never see any meaningful railroad electrification (outside of government intervention) in North America. It is more likely that either (1) Congress will finally relent and allow the US to become energy independent via a lifting on drilling restrictions in ANWR, the OCS, oil shales, etc which will bring down the cost of petroleum based diesel fuel, and/or (2) CTL fuel will be used to supplement our domestic supply of diesel/heating oil. Coal-fired reciprocating steam, although the logical lowest cost choice, probably has too much of a "backward" perception associated with it, and since our rail system is an integrated private oligarchy there is no real free market pressure to cut operating costs to that degree (e.g. railroads for the most part can easily pass on fuel costs to the shippers without losing market share).

One more item. NO, utilities do not want to have to deal with more unscheduled power offerings into the grid. It's bad enough we are required to take excess power generated from unpredictable wind turbines (which usually occurs when we really don't need it e.g. operating at normal baseload demand - it never seems to blow when demand is peaking!). Now, if an electrified railroad ran on tight schedules and thus could give utilities a reasonable time frame for when they would be going into regenerative braking for excess power into the grid, preferably during peak usage periods, then at least we could fit it in without too much disruption.