updated 08:58 pm EDT, Thu June 21, 2012
Effect of iPad growth on overall US power consumption evaluated
A new study has revealed exact figures on how much money users spend charging their iPads and iPhones. According to the Electric Power Research Institute (EPRI), charging a current-generation iPad every other day from completely drained costs the user $1.36 per year. The study's intention is to evaluate the United States' year-over-year power use, but EPRI extended the test to understand whether the rapid growth of tablets in the "post-PC era" is adding to power consumption, or reducing it.
If users are altering computing habits, such as surfing on a tablet rather than on a comparatively power-hungry desktop, then overall computing power consumption will fall. Consumers shifting from television-based video gaming consoles such as the Xbox 360 or PlayStation 3 to smaller touch devices also reduces overall power consumption. However, if tablets are being used as adjuncts to existing technology, used in parallel, an increase in power consumption is clear. Now that averages for various devices based on the cost of a kilowatt hour in the US has been determined, a future study will investigate whether users are using the devices alongside their usual, higher-power machines or in place of them.
Other annual power consumption comparisons based on an electricity cost of 11.9 cents per kilowatt-hour include a 60-watt-equivalent compact fluorescent bulb costs $1.61, running an average-power desktop PC at $28.21 per year, cable set-top boxes consume $30 of power per year, refrigerators at $65.72 per year, a clothes dryer runs $105 per year, Energy Star-labeled central air conditioning costs $140 per 900 hours of runtime, and a conventional electric water heater crushes the meter at nearly $400 per year. Charging costs for first- and second- generation iPads are about 84 cents annually, with 38 cents to charge an iPhone 4 for a year based on the same every-other-day charging usage.