What would be the approximate cost of running a computer, a router and two roof mounted cameras in terms of electricty 24/7? That is energy only.
That question is about as vague as asking "What's the average fuel consumption of an aircraft ?" ...... is that fixed wing or rotary ? how many engines ? etc.
Same applies in all the gadgetry. Some of the latest and greatest stuff uses tiny amounts of power..... for example some reasonably beefy
servers mid-range servers from HP's latest ranges will only pull around 0.5 amps idling and 1 amp when you're pushing them.