Apple's iPad costs you $1.36 per year to charge

Apple's iPad costs precious little for you to charge it each year, according to a new study.

The Electric Power Research Institute (EPRI) conducted a study recently to see how much the iPad costs in electricity if users fully charge it every other day. The research agency, which is funded by electric power companies, found that the iPad will cost owners $1.36 a year, thanks to its consumption of just 12 kWh of electricity each year.

The EPRI assumed that there are now 67 million iPads in the world and applied the average energy use to each device to arrive at a total of 590 gigawatt hours of overall usage. In the event the number of iPads worldwide triples over the next two years, the energy required to power the devices would equal two 250-megawatt power plants operating at 50 percent utilization, according to EPRI. A quadrupling in sales would require three plants.

The crux of EPRI's findings, however, rests in the impact the iPad might be having on overall usage. Although it's consuming power, more and more people are using the device for gaming, video consumption, and Web browsing, effectively taking the power load away from higher-consuming products.

"These results raise important questions about how the shifting reliance from desktop to laptop to mobile devices will change energy use and electricity requirements for the information age," Mark McGranaghan, vice president of power delivery and utilization at EPRI, said in a statement. "At less than a penny per charge these findings bring new meaning to the adage, 'A penny for your thoughts.'"

EPRI stopped short of saying that devices like the iPad and other tablets will help conserve power, since it's hard to predict consumer actions. However, the organization did note that laptops consume about 72.3 kWh of electricity each year, costing folks $8.31. A 42-inch plasma television consumes an average of 258 kWh each year.