flat screen TV - output is high - costs £8-£10 a week on electricity?

Just put in a 3 amp fuse and all will be fine.

15p per kw, 5 hours =1kw (15p) 168hrs in a week= £5.04p

Spot on there Ibrahima, but who would watch TV for 24 hours per day?

I can't believe this is like for like.
My old big CRT TV was a heater, it used piles of powerm you could feel the heat off the back.
FFS they are basically valve technology.
My new bigger TV was a lot less power, I remember doing the numbers at the time.

Secondly power is generally "heat", not always "waste" unless your are in california. I notice myslef that with heating off my living room is always warmer than the next room. Partly the TV, the computer, mostly the room is just hot from fan-tas-tic I look on a couch in y fronts, as seen on my "Betfair men of the naked group hug" charity calendar shot.

You need the latest LED TV's ...much lower power consumption !
My old 37" Panasonic Viera Plasma  - 250 watts !
Mind you been going strong for over 10 years and brilliant picture still... so reluctant to change it.
Putting in a lower (3 amp) rated fuse would make no difference (was it a joke?)...makes no difference to a units power consumption.   
A 200w TV draws less than 1 amp.
W (watts) over V (Volts) gives you I (amps).

Putting in a lower (3 amp) rated fuse would make no difference (was it a joke?)...makes no difference to a units power consumption. 

Of course it was a joke!!  I have the 42" Viera LCD which on checking is 188 watts.

So Plasma is a higher wattage then?

Plasma was always a higher wattage AFAIK and an intermediate technology unitl they sorted LED tvs out correctly. Also they are more fragile, heavier, and still can suffer from burn in, LED/LCD TVs don't.

How did you work out the costs involved Sonko?

Wer've a 50" Plasma that puts strain on Sellafield. Even when a TV is on standby it draws a lot of power.

Ovalman if you want ot work out wattge you've 3 ways:
1. Look at specs ....
2. Use a 3rd party power monitor (I've one) to see.
3. Easiest:
Look at the meter in your house without TV on.
Without other changes (like timed immersion) put TV on for say two hours, on the button.
Don't make cups of tea.
4. Read meter.

Between 3 and 4, the difference is your answer.

Ovalman, that is just the max it could cost if it is on 24/7 per week. his 200w tv left on for 5 hours would equal 1kw (200wx5hrs) or 15p.

if he only had it on 6hours per day (6hrx7days=42hr/5x.15p) £1.26

Find out the wattage of your tv when in use and on standby.