evnow wrote:They probably picked it from some study - but is probably presented wrong. I won't be surprised if the total energy input to get oil (from well to tank) is 7.5 kwh / gallon.
Besides oil refining, the other major use of energy in a well-to-tank analysis is oil production (getting it out of the ground). The transportation and marketing of oil and refined products is relatively small by comparison.
The same source of electricity used to refine oil also has some numbers for oil extraction here:
http://www.nationmaster.com/graph/ene_e ... eum-fields
This indicates 33.636 billion kWh to extract oil in the US in 2005.
In 2005, the US produced 8,321,800 b/day = 349,515,600 gal/day = 127,573,194,000 gal/yr of crude oil. (source: US EIA)
So the electricity usage per gallon for oil extraction in the US = 33.636 billion kWh/yr / 127,573,194,000 gal/yr = 0.26 kWh/gal. So it still well under 1 kWh/gal. I don't know how much of this electricity comes from byproducts of petroleum production but it might be a lot. I don't believe they run high voltage power lines out to offshore oil platforms, for example. I think they generate their own electricity on site using byproducts of petroleum production.
If we added up all electricity used to take oil from well to tank it's going to be under 1 kWh/gal. Not anywhere near 7.5 kWh/gal.
In the US, a tiny fraction of the petroleum-based fuels produced is burned to make electricity, and this produces about 54.2 billion kWh/yr of electricity. In some other countries a larger fraction of oil products is used for electricity production. The US exports some petroleum-based fuels that are burned in other countries to make electricity.
I think a more interesting metric would be the amount of natural gas used to take oil from well to tank. We'd need to add up the natural gas used to make electricity and steam, and the natural gas used in fired heaters. We could compare this how much electricity could be delivered to EV batteries if all that natural gas was instead used to make electricity, though we need to subtract the 54.2 billion kWh/yr produced from burning refined fuels in the US and however much electricity is created from the petroleum coke, etc. that the US exports to other countries. If we do that I'm believe the bottom line will still work out to a lot less than 7.5 kWh/gal.
The natural gas used as feedstock in the manufacture of hydrogen for hydrocrackers and hydrotreaters in oil refineries would not "count" for this purpose because it isn't a "fuel" used in a well-to-tank calculation. Hydrogen is a raw material that is used to make refined products just as the petroleum is a raw material used to make refined products.