I like doing thought experiments. I often use them to help me envision the parameters of a complex problem. For example, a dozen years ago I attempted to calculate the area required to supply the entire U.S. with electricity from solar photovoltaic (PV) power.
Admittedly, these thought experiments require major simplifications. To completely run the U.S. on solar power would require a substantial amount of backup power or storage for when the sun isn’t shining.
I also knew that my solar PV calculation was subject to many assumptions, and the answer could therefore be 50% too large or 50% too small. But the number I calculated — an area less than 100 miles by 100 miles — at least provided me with a point of reference for the scale of such an undertaking.
I wanted to imagine about how much area it might take, and that calculation gave me a ballpark figure to visualize. The National Renewable Energy Laboratory (NREL) once calculated that there are about 2,000 square miles of suitable area for PV generation just on U.S. rooftops. So it didn’t seem like a preposterous notion.
In the dozen years since I did that calculation, U.S. solar power generation has increased by a factor of 66. U.S. wind power generation, which started from a larger base at that time, has increased by a factor of five. The number of electric vehicles (EVs) on the roads has also grown exponentially in the past decade.
That led me to wonder how much U.S. gasoline demand could be displaced if all of the wind and solar power generation went into powering EVs. In turn, that led me to wonder about the scale of displacing all U.S. gasoline consumption with wind and solar power.
Again, I will note that this is just a thought experiment. It isn’t constrained by issues like the number of available EVs, or the amount of storage required to ensure that the power is always available on demand. With those caveats, I will attempt the calculation — with no idea beforehand how it is going to turn out.
According to the Energy Information Administration (EIA), in 2019 the U.S. consumed 142 billion gallons of gasoline. The EIA value for the energy content of a gallon of gasoline is 120,286 British thermal units (Btu). Thus, in 2019 the U.S. consumed 17 quadrillion Btu (quads) of gasoline.read more