From Ken Cohen … How many gallons of gasoline would it take to charge an iPhone?:
This may seem like a strange question to ask, considering iPhones obviously are charged with electricity, not gasoline.
But the answer speaks to why gasoline and other liquid fuels will remain an important part of the energy mix in the future.
In ExxonMobil’s recently released Outlook for Energy, we predict that by 2040, about 90 percent of the global transportation fleet will still be powered by liquid petroleum fuels – that is, gasoline, diesel, and jet fuel.
When asked why that’s the case, Bill Colton, ExxonMobil’s vice president for Corporate Strategic Planning, often starts the discussion using this fact to put it in perspective:
All of the energy concentrated in one gallon of gasoline is enough to charge an iPhone once a day for almost 20 years.