Do you believe in magic? Big Oil and their supporters hope so, as they advocate their latest domestic energy source: oil shale.
Oil shale is neither oil nor shale. This finely-grained sedimentary rock - more properly known as organic marlstone - is infused with kerogen, not oil. Kerogen is a dense blend of ancient algae and pond scum, and is an essential ingredient in oil and natural gas. But transforming kerogen to oil requires millennia, coupled with intense heat and crushing geologic pressure. Otherwise the kerogen remains a relatively energy-poor waxy deposit in sedimentary rocks, such as oil shale.
The United States is home to huge deposits of oil shale, most of which can be found somewhere beneath the Rockies. But before rushing for our shovels, we must consider the costs. Is oil shale worth it?
Fuel sources are measured by their energy density - the amount of heat that can be generated per pound. The kerogen in oil shale, which was not refined by eons of heat and pressure, has a very low energy density. As a result, oil shale remains perhaps the poorest choice among the carbon-based fuels. For comparison, oil shale contains one-tenth the energy of crude oil, one-sixth that of coal and one-fourth that of dried cow manure. Pound for pound, oil shale has roughly the same energy density of a baked potato.
Energy speculators have flirted with oil shale since the late 1800s. Every oil shale boom eventually turns to bust when the returns fail to justify the costs. The rocks must first be heated to approximately 600-970°F. This cooks the kerogen, resulting in an oil-like substance known as shale oil. The shale oil then must be further modified to create a synthetic fuel that can be substituted for crude oil. The entire process requires massive inputs of heat, energy and water, and produces a volume of pollutants and gases.
Refining synthetic oil from shale is a dirty, thirsty and destructive process. Mining the rocks damages landscapes and ecosystems, increases erosion and pollutes water and air with acidic run-off, sulfur-gas emissions and air-borne particulates. Experimental attempts to convert kerogen without mining holds additional environmental risks, including groundwater pollution. The whole process - from extraction through conversion - may require five barrels of water per barrel of synthetic shale oil, if not more. The U.S. oil shale deposits lie within arid Colorado, Utah and Wyoming, where citizens are concerned their sparse drinking water may be redirected to support environmentally damaging and wasteful oil shale speculation. Coupled with all this, producing and using oil from shale creates even more greenhouse gas emissions than conventional petroleum.
Environmentally destructive and prohibitively expensive, oil from shale is not worth the costs. Certainly we must secure our energy future, but oil shale should not be part of this process. This is not the fuel of the future. It’s time we recognize oil shale for what it is, a rock.
As always, the answer comes back to conservation and investment in alternative energies. These may not be easy or immediate answers, but they are the only ones that will work.