# How much coal does it take to charge an iphone?

Asked by xioioix (92) September 14th, 2008

Does anyone know how much coal it takes to generate enough electricity to accomplish a common goal? i.e. charge an iphone, run a 60 watt bulb for one hour, etc?

Observing members: 0 Composing members: 0

This may help, I don’t know about the facts behind it, although it does cite this which may help to.

Hope this helps, it’s certainly an interesting topic :)

Skyrail (1695)

Takes only about half a pound, but I have to keep stoking it which is a pain.

AstroChuck (37428)

I just use electricity to charge mine. It’s so much easier!!!

loser (15012)
Zen (7738)

The energy density of coal is about 30 MJ/kg. A 60 watt bulb running for one hours is 60W x 3600 seconds = 216,000 joules or 0.22 MJ. So it would take 0.22/30 = .007 kg of coal if the system was perfectly efficient. Let’s figure 50% efficiency at the power plant and 50% efficiency in the lines to your house.
That will make it ~0.007kg x 4 = 28 grams of coal to power a 60 Watt light bulb for one hour with typical efficiencies.

LuckyGuy (38072)

or