It won't be easy to run a national railway on renewable energy like wind, hydro and solar power but that is what Germany's Deutsche Bahn aims to do for one simple reason: it's what consumers want.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/german-rail-run-sun-wind-keep-clients-happy
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/planet-ark-australia
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/germany
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/rail-transport
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/renewable-energy
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/wind-energy
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/solar-energy
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution-control
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/nuclear-power
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/transport
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/carbon-dioxide