How much power does your iPad really use?

So I was at a meeting recently where someone bemoaned the costs of delivering power to iPads. This was in a school situation so they were looking potentially at the cost of charging 1000 iPads. But what would it actually cost?

Although I can’t source the original, there are many articles from last year quoting a study by the Electric Power Research Institute (eg this article from Gigacom) which says that if you were to fully recharge your iPad from empty every couple of days it would consume just under 12 kWh of electricity over the course of a year. By comparison, a plasma 42” television consumes 358 kWh.

At, say, $0.25 per kWh that would come to $4 pa. Most people are paying less than $0.25 per kWh and don’t fully drain their iPad over two days – so that $4 is probably the higher-end cost. So even allowing for variation in usage and cost that’s not a lot of money compared to the cost of purchasing an iPad in the first place.

In the specific school context it was raised you would only be charging when school was on, let’s say 280 days; so, doing some brutal rounding, that would be an annual cost of around $3,000 always assuming schools pay something like domestic electricity rates. $3000 is a lot of money for some schools, relatively less for others. But putting this in another perspective charging an iPad draws less power than using a compact fluorescent light-bulb.

There are many, many complex issues with the use of iPads in schools, but I’m going to say electricity is not foremost amongst them.