Paul you are right, but that doesn't tell the whole story.
When it comes to airplanes, it's totally oil dependent. There's lots of coal hanging around AFAIK but you can fly a plane on it. We have several different types of fuel not available to aircraft but that are available to electric railways.
You can power a lineside power plant with coal, peat, or if we really wanted to get adventureous, biomass plants such as Miscanthus.
Try running one of Mickey O Leary's planes on Peat
There is also that little matter of renewables, we have a huge reserve of wind, rivers and tidal energy that could be harnessed, it may not happen in the short term but eventually it will - I mean look at Germany, take a train (electric) from Berlin to the Dutch border and you'll lose track of all the Wind Farms you see. The Germans would love to have even a fraction of our natural resources.
Also, we could import Nuclear electricity from Britain also, as there are a couple of electricity Interconnectors between Ireland and Wales.
If we want a transport system that is environmentally friendly(er) and based heavily on electric railway transport, it can be done. Obviously a lot of work needs to be done though between now and 2050.