DMcG, you believe every scare story. Both sides of the border generate power but exchange it to smooth out supply. Both sides would be stupid to change that arrangement, but if the EU was that stupid NI would only struggle with peak demand occasionally. Why do you suggest any problem with fuel? Now you are making up scares.

Anyone who says that is blind to the fact that the Irish border, for example, is politically and socially important to the EU and has been a key factor from the start.

You seem to be blind to some facts. Britain will not impose border infrastructure. We can manage without it. The Republic would be stupid to let EU force them to do it. It will not happen whatever they say.
The main road crossing is all that could be controlled anyway. The other 200 crossings along the 300 mile border could never be. It is all just scare tactics.