how much extra electricity will need to be consumed with the digitalization of televisions throughout the coun

Answer 1

If they get intergrated TV's , they wont use anymore than conventional tele's.

Once they switch off the analogue system, it will use about the same .

Flat screen LCD tv's use less than CRT , digital equipment uses less than conventional equipment

Answer 2

No idea, possibly less. Assumning that people change their televisions to take advantage of the higher quality signal then its conceivable that the new TV's could be LCD's which consume a lot more power. Of course if they chaneg to Plasma then it may go up.
It also depends on whether they buy an additional box to decode signals or use an integrated receiver.

it also depends if the powers upply companies can maitain an adequate supply, if they turn the power off due to lack of power then power demand may go down.

Answer 3

Generally speaking newer televisions consume less electricity than older ones, so since digital television will ultimately cause everyone to replace their television, you could argue that overall consumption will be reduced.