Electrification of US railroads may be a better alternative to the steam locomotive. The Europeans have been doing it for nearly a century now. That way large scale power plants can produce the needed power on a much more efficient scale by what ever means is available and eliminate the need for the extra cost of hauling a less efficient prime mover around with you. The big initial cost of the overhead and power distribution would need to be over come however. Another big advantage of electrification would be the use of regenerative braking where a down hill train could supply some of the power to lift another one going up hill.
Roger Mitchell