photo: Stuart Caie via flickr
In case you needed more convincing that developing the United States' oil shale deposits into liquid fuel is an environmental nightmare and a complete non-starter from an energy perspective, Western Resource Advocates has just released a new assessment of the energy return on investment that details it all. Here are the stats to keep in mind:Though the report acknowledges the difficulty in firmly establishing a figure for energy return on investment for oil shale, the report notes that "the most reliable studies suggest that the EROI for oil shale falls between 1:1 and 2:1 when self-energy is counted as a cost." Self-energy refers to energy released when processing oil shale that is fed back to power the process.
This is not a surprising result considering the natural resource exploited in each process. The kerogen in oil shale is solid organic material that has not been subject to the temperature, pressure, and other geologic conditions required to convert it to liquid form. In effect, humans must supply the additional energy required to "upgrade" the oil shale resource to the functional equivalent of conventional crude oil. The extra effort carries a large energy penalty, producing a much lower EROI for oil shale.
That high amount of energy required to process the oil shale results in high greenhouse gas emissions. Compared to conventional sources of oil, Western Resource Advocates calculates that fuel produced from oil shale emits 1.2 to 1.75 times the greenhouse gases.
Then there is the water consumption: For each barrel of oil produced from oil shale, 1-3 barrels of water are required--especially not insignificant consider the general arid environment where US oil shale deposits are located.
Read the report: An Assessment of the Energy Return on Investment of Oil Shale [PDF]
More on Oil Shale:
Mr Secretary of Interior, Oil Shale Development Can Never Be Environmentally Sustainable
Oil Shale Plant Powered by 'Clean Coal' - And Cooled by Colorado River Water?
Economic, Environmental Costs of Developing Tar Sands & Oil Shale 'Unthinkable'