It was announced last night 3 Helicopters would be coming to NI  to assist with restoring the electrical grid. They seem to be in the air now. (14:56)
G-RIDC - Bell 429 GlobalRanger - National Grid
G-WPDE - Airbus Helicopters H135 - National Grid
Also operating is 
G-NLSE - Aerospatiale AS355 F2 Ecureuil 2 - PDG Aviation Services
Not sure if it is part of the operation, but going by movements it seemed to be involved in something. 
			
			
			
				Possibly bringing in some generators?
			
			
			
				1325 G-RIDC - Bell 429 GlobalRanger - National Grid heading to NE Antrim.
1330 G-WPDE - Airbus Helicopters H135 - National Grid heading towards Sperrins 
			
			
			
				I'm assuming it was G-RIDC that passed high over Bangor area on its way back to the mainland yesterday morning.