Not those ludicrous scare stories again!
From your article,
"Senior energy industry figures have told the Guardian that Northern Ireland is not sustainable as an energy market on its own, because of its relatively small size.
However, they believe that in the event of a no-deal Brexit and the SEM collapsing, a way would be found to keep electricity supplies running cross-border."

Why would the link to Scotand have to close?
The link to RI flows both ways, mostly out of NI.
RI relies heavily on that link and one to UK mainland. They are the ones at risk.

"Previous government leaks have suggested that a flotilla of electricity generators on barges could be sent to Northern Ireland if the UK crashed out of the EU."

All bollocks. If true why not put them on lorries and drive them to suitable locations?