The net energy, or “energy returned on energy invested,” of unconventional sources such as tar sands and shale gas is generally much lower than for conventional resources, according to research by the Post Carbon Institute.
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.
Furthermore, such fuels suffer massively from the law of diminishing returns, according to the report. Overall field decline rates are so steep that 30 to 50 percent of shale gas production and 40 percent of shale oil production must be replaced annually to offset declines, the report says.
In January 2012, President Obama refused to approve the proposed $7 billion Keystone XL oil pipeline, which would run 1,700 miles between the Alberta oil sands and Texas Gulf Coast refineries. Obama left the door open for backers TransCanada to submit a new permit application, blaming his rejection on a 60-day deadline set by Congress. The White House also backed the company’s plans to build a major portion of the pipeline – a $2.3 billion section called the Gulf Coast Project, which runs from Cushing, Okla., to Texas.
In December last year, fruit producer Chiquita Brands became the 15th company to stop using oil sourced from Canada’s tar sands, following a campaign by environmental group ForestEthics. The environmental group had targeted Chiquita and fellow fruit producer Dole in a campaign launched in August.
ForestEthics took out full-page adverts in USA Today to highlight and criticize the companies’ use of oil from Alberta tar sands for shipping and refrigeration. The group subsequently encouraged its supporters to bombard the fruit firms’ Facebook pages with criticism of their tar sands oil use, effectively forcing Chiquita to temporarily shut down its page’s comments section, the FT reports.