Re:Apple is working with Energous on wireless charging
by simcop2387 on Friday September 16, 2016 @01:38AM
(#12512062)
Actually a 50% efficiency loss would double the energy requirements to 800+ billion watt hours. Your original calculation is right for 100% efficiency in charging over wires.
Re:Apple is working with Energous on wireless charging
by mikeyouse on Friday September 16, 2016 @01:48AM
(#12512106)
Ah! Good point. I can't edit but double the turbines.
If we say the new generation iPhones have a 3,000mah battery, batteries are charged fully once per day, and that 100 million people in the US have iPhones:
3,000mah x 3.8v = 11.4 watt-hours to fully charge a phone -- at $0.15/kWh, this equates to a daily expense of ~$0.002 to charge your phone. Annually, this is $0.62. If wireless charging were 50% efficient, it would still cost under a dollar annually to charge your phone.
On a bigger scale:
11.4Wh * 365 days * 100M phones = 416 billion watt-hours annually to charge all the iPhones in the US. A 50% efficiency loss would equate to a difference of 208 billion Wh.
Enercon makes a monster wind turbine called the E-126 that has a 7.6mW generator attached. With a modest 40% capacity factor, you would only need 8 additional wind turbines to make up for every iPhone user in the US switching to wireless charging.