PCI Fellow David Hughes' research on tar sands in his new report Drill Baby Drill was featured in this article at Environmental Leader.
From the article:
The average net energy or rate of return for conventional oil is about 25:1, meaning that it takes one unit of oil to extract every 25 units of oil from the earth. With minable tar sands this figure falls drastically to 5:1 and for “in situ” tar sands retrieved from deeper in the earth the ratio is 3:1, according to the report, Drill Baby Drill.
From a net energy point of view, moving to progressively lower-quality energy resources diverts more and more resources “to the act of acquisition as opposed to doing useful work,” the report says. The environmental impact of extracting resources also generally increases as net energy yield declines, both from the physical impact on the landscape and in terms of greenhouse gas and other emissions.
Image credit: Tar sands, Alberta - howlcollective/flickr