The average “energy returned on investment,” or EROI, for conventional oil is roughly 25:1. In other words, 25 units of oil-based energy are obtained for every one unit of other energy that is invested to extract it. But tar sands oil is in a category all its own. Tar sands retrieved by surface mining has […]
What isn’t often mentioned, Hughes said, is the energy required to extract the oil, or the rate at which it can feasibly be recovered.
“Unless we talk about all three metrics—size of the resource, net energy and rate of supply—we’re not getting the full story,” he said.
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Hall, who wasn’t involved in Hughes’ study, thinks the EROI for oil sands would fall closer to 1:1 if the tar sands’ full life cycle—including transportation, refinement into higher quality products, end use efficiency and environmental costs—was taken into account.
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