How much energy is used by a light bulb in 2,190 hours?

Question

This is a random question, I know. But it's for a paper I'm writing.

Also, can you site something that uses an equivalent or similar amount of energy to that?

Another extra would be if you know how much that would cost... to have a light bulb on for that long.

Thanks so much!

Answer 1

A 60 watt bulb would be 60 * 2190 = 131,400 watts or 131.4 kw @ 8.00 cents a kw it would cost $10.51

Answer 2

1 watt = 1 joule per second

So for a 60W light bulb, that's 60 joules per second

60W * 60 *60 * 2190 = 473040000J

Typical kettle: 2KW

473040000J / (2000W * 60 * 60) = 65.7 Hours

So, 60W bulb for 2190 hours = boiling a kettle for 65.7 Hours

Another example: 750W microwave oven

473040000J / (750W * 60 * 60) = 175.2 Hours

So, 60W bulb for 2190 hours = microwaving something for 175.2 Hours

Since you posted in "green living", lets do an energy efficient light bulb equivalent (mine is 13W which is supposed to be as bright as a 60W incandescent bulb):

473040000J / (13W * 60 * 60) = 10107.9 Hours

So, for the same amount of light (and energy) from (and used by) a 60W incandescent bulb switched on for 2190 hours, you could power an energy efficient bulb for 10107.9 hours.

I did all of these calculations and was amazed when i saw that last result. I can see why they call them energy efficient!!! Almost 5 times more efficient.

Hope that helps! It definitely opened my eyes!

EDIT:

In 2005, the price per KWh was about 6p in the UK if I remember correctly. So running the incadescent bulb for 2190 hours would have cost:

60W * 2190h = Approx. 131KWh >> so 131*6p = 786 pence

The energy efficient bulb on the other hand, would have cost:

(13W * 2190h) * 6p = 171 pence

Much cheaper. Those energy efficient bulbs also last a lot longer (we're talking years longer!)

Answer 3

That depends on the wattage of the bulb. A 100 W bulb will burn 219 kW in that time. Simple multiplication.

The cost is also variable. Look at your utility bill to learn the cost of electricity in your area, then multiply again.