A friend of mine did an interesting bit of research and data gathering that I’ve not seen elsewhere and I thought I’d share here.

If you read about energy and markets, you might have read about EROEI: Energy return on energy invested. E.g: It might take 20 gallons of oil to extract a 55g barrel of oil.

So what’s the energy cost to refine a gallon of gasoline?

To get an answer, my friend found the government page showing the energy used by “Petroleum Administrative for Defense District 5. Basically, west-coast refineries.”. It’s here. A snapshot graph:

Next, you need to know how much they refined (oil in, gasoline etc out). That’s here. And the refining capacity is here.

If you do the math (to tip my hat to a scientist I admire), the result is 8.6kWh/gallon. To get that number, you

• take the annual electricity purchased by the refinery (X)
• Calculate the proportion of gasoline vs total refined output (Y) (19.45 gallons gas per 44.77 gallons refined output)
• Divide X/Y

That’s more than I would have guessed. Our 2018 Chevrolet Bolt EV holds about 60kWh and can drive around 180 miles, by way of comparison. So the refining energy could power an average EV sedan 34 miles. Which is higher than the average EPA mileage of a comparable ICE sedan.

Food for thought. As my friend put it, “charging an EV will always require less energy than an equivalent gasoline powered vehicle, and would always be cheaper for the end user if not for subsidies to the petroleum industry.”