What if it were possible to bury carbon dioxide over a mile below a power plant in the second worst air basin in the United States? In 2011 the greenhouse gas will be pumped below a power plant in the southern San Joaquin Valley of California.
Located in Kern County near Bakersfield, the Clean Energy Systems power plant is powered by different kinds of natural gas and oxygen. It produces five megawatts of energy, enough for 5,000 homes, but the carbon sequestration experiment will increase that to 50 megawatts.
The West Coast Regional Carbon Sequestration Partnership (WestCarb), made up of 70 different organizations and led by the California Energy Commission, will manage the project. One million tons of compressed carbon will be injected into underground rock formations over a four year period.
"The central valley is geologically perfect for this type of research because of the way the earth is structured, the way the strata are configured," said Adam Gottlieb, California Energy Commission spokesperson. "Other regions are using different versions of the application."
Last spring the project received a $65 million grant from the Department of Energy (DOE). The federal government has funded a half-dozen other carbon sequestration projects located in the Midwest, Southwest, and Northwest.
The basics of carbon sequestration
Carbon sequestration is also called carbon capture and storage (CCS). Carbon can be captured in two ways according to WestCarb: "enhancing natural processes that remove it from the air and by modifying industrial plans to remove carbon from process or exhaust gases before their release."
According to Lawrence Berkeley National Laboratory, a WestCarb member, carbon sequestration "involves pumping carbon dioxide into porous formations capped by impermeable rock, which prevents the greenhouse gas from escaping into the atmosphere and contributing to global warming." In order for carbon to not escape after it is buried, it must be injected into geologic formations that are secure such as unmineable coal beds, depleted gas and oil reservoirs, and saline formations.
The Department of Energy's (DOE) Carbon Sequestration Program (CSP), managed by the Office of Fossil Energy, is developing technologies in order to make CCS an effective and economically viable way to reduce carbon emissions. The program launched in 1997. According to the DOE's website (pdf), the goal of the CSP program is to "develop, by 2012, fossil fuel conversion systems that achieve 90 percent carbon capture with 99 percent storage permanence at less than a 10 percent increase in the cost of energy services."
The U.S. is responsible for one-quarter of all worldwide carbon emissions from fossil fuels. CCS has the capacity to capture and store about 1.2 trillion to 3.6 trillion metric tons, according to a 2007 study by the Congressional Budget Office (pdf).
Critics of CCS point out the danger it would pose if any of the stored carbon leaked. The Union of Concerned Scientists warns that although proponents of CCS acknowledge environmental and public safety risks, "these environmental concerns are insufficiently studied through systematic research to date."
According to the UN's Intergovernmental Panel on Climate Change (pdf), (IPCC), "Physical leakage rates are estimated to be very small for geological formations chosen with care." The IPCC estimates that a 99 percent retention rate of the carbon stored would be "very likely" over a 100 year period, and "likely" over a 1,000 year period.
Since 1996, Norway's state oil company, Statoil has safely injected "about a million tons" of carbon every year beneath the North Sea. It cost $80 million to build the injection facility which takes excess carbon from Statoil's offshore platform and injects it 800 meters under the seafloor.
The costs for CCS range from $100 to $300 per ton of carbon emissions, according to the DOE. The goal of the DOE's CCS program is to reduce the cost to $10 or less per carbon ton by 2015, which would save the U.S. "trillions of dollars."
False hope?
Greenpeace leveled four main criticisms of CCS in its report titled False Hope: Why Carbon Capture and Storage Won't Save the Climate (pdf). The first criticism in the report states that CCS can't deliver on time to avoid dangerous climate change. The United Nations Development Program (UNDP) agrees: "CCS will arrive on the battlefield far too late to help the world avoid dangerous climate change."
The report cites the fact that the Intergovernmental Panel on Climate Change (IPCC) "does not expect CCS to become commercially viable until at least the second half of this century."
Friends of the Earth (FOE) also believe CCS is not a viable means to mitigate climate change. FOE climate campaigner Louise Morris said, "Attempting to bury our greenhouse gas pollution underground is akin to burying our heads in the sand. This is not the way to reduce our greenhouse emissions."
The second criticism in the Greenpeace report cites the cost of CCS. According to the calculations of the U.S. Department of Energy (DOE), the installation of CCS systems will "almost double plant costs," and lead to "electricity price hikes of anywhere between 21 and 91 percent."
The third criticism points out that CCS wastes energy. According to the report, capturing and storing carbon uses 10 to 40 percent of a power plant's capacity. "An energy penalty of just 20 percent would require the construction of an extra power station for every four built."
The World Wildlife Federation estimates that CCS would increase the costs of generating power by 40 to 80 percent.
Greenpeace's final criticism of CCS is that it is risky to store carbon underground. The International Energy Agency's estimates for CCS to "deliver any meaningful climate mitigation effects by 2050" are that 6,000 projects are needed which each inject a million tons of carbon every year into the ground." The report points out that presently it is not technically possible to store that amount of carbon underground.
In Tim Flannery's book The Weather Makers, he expressed his concern about CCS. He pointed out that carbon escaping from a geological formation it was injected into "has the potential to kill."
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