That's according to the Electric Power Research Institute (EPRI), a nonprofit organization that conducts research and development relating to the generation, delivery, and use of electricity.
With the growing use of portable electronic devices, the folks at EPRI wanted to see if all of these additional devices were going to change the load demands on the electrical grid.
Their summary judgement about the amount of change: not much.
In fact, if these devices are used as replacements for desktop systems, as many of them like the iPad are, then the net effect may actually be a decrease in power demand. A typical desktop system may demand up to 20x the amount of power over the iPad.
EPRI calculates the average energy used by all iPads currently in the market at 590 Gigawatt-hours (GW-hr), or the equivalent of a 250-MW powerplant operating at just a little over 25% utilization. If the iPad is fully charged every other day, it will use less than 12 kilowatt-hours (kW-hr) of energy a year. As a comparison, a 60-W equivalent CFL lamp uses 14 kW-hr per year ($1.61), a laptop 72.3 kW-hr ($8.31), and a 42" plasma television 358 kW-hr ($41.15).
Operating costs are based on the national average of 11.49ยข/kW-hr. Specific costs will vary based on the price of electricity at a particular location.