That coffee you're drinking while gazing at your iPad? It cost more than all the electricity needed to run those games, emails, videos and news stories for a year.

The annual cost to charge an iPad is just $1.36, according to the Electric Power Research Institute, a non-profit research and development group funded by electric utilities.

By comparison, a 60-watt compact fluorescent bulb costs $1.61, a desktop PC adds up to $28.21 and a refrigerator runs you $65.72.

The group, known as EPRI, studied the power consumption of Apple Inc.'s iPad to determine the effect that the newly-popular devices might have on the nation's electricity use.

The answer: not much.