how to calculate electricity usage?

alirob12

hi, can anyone tell me how to calculate electricity usage?

I have 7 500w lights outside and I pay 20p for 1kwh. Would anyone tell me how much it will cost me to have them on for 1 hr?

Thank you

tronator

alir!!!2 wrote: »

hi, can anyone tell me how to calculate electricity usage?

I have 7 500w lights outside and I pay 20p for 1kwh. Would anyone tell me how much it will cost me to have them on for 1 hr?

Thank you

Over the thumb it's 7*0.5*0.20 = £0.70

An electrician or physicist will tell you that you have to multiply it by co-sinus of "something". It's a long time since school for me

spud17

No
70p g:cool:et a calculator

alirob12

thank you, so if i changed bulbs to 150w it would b 7 x 0.15 x 0.20? = 0.21?? thanks

tronator

alir!!!2 wrote: »

thank you, so if i changed bulbs to 150w it would b 7 x 0.15 x 0.20? = 0.21?? thanks

Right, or even better use energy saving bulbs if possible.

alirob12

hi, thank you , yes i do use energy saving bulbs everywhere else. These are my security flood lights, which i only used a couple of times but wanted to know how much it costs etc.

Thank you

kwikbreaks

Better still change your energy supplier. 20p per kwh is very expensive - mine is 9.5p with a pretty minimal standing charge.

alirob12

thx I actually did (new property) changed it and it kicks in on June 18th. It used to be 20p, it will be a lot less now, so thats even better thank you all!!