# How much would an 80 watt shoplight cost per month?



## booboo (Jan 22, 2005)

How much does your average shoplight cost a month? This doesnt worry me as i am running all sorts of stuff but my friends parents dont want him using much electricity. 
I am trying to calculate how much each 80 watt shop would cost per hour to run?

Or how much would a 150 watt high pressure sodium light cost to run per hour?


----------



## Blort (Feb 5, 2005)

That depends on how much you are paying per kW hour. You take the number of watts, multiply by the amount of time used, convert to kW and multiply by the kW hour rate.

So, let's say it costs about $0.07 per kW hour:

Get the number of watts used:
80w + 150w = 230w

Running for 12 hours a day:
230w x 12 = 2760w

Convert to kW:
2760w / 1000 = 2.76 kW

Get the daily cost:
2.76kW x $0.07 = $0.1932

I think that's right. It's late and I'm tired. Maybe Mike can verify.

Marcos


----------



## defaced (May 23, 2005)

That's right. You'll have to look at the electric bill to see how much a kW of electricity costs.


----------

