The Government Accountability Office (GAO), the investigative arm of the U.S. Congress, just released its report on the status of carbon capture and sequestration (CCS) technology and its view of the technology’s future development challenges. In general, the GAO concludes that the technology faces grave technological, regulatory, economic, and legal barriers that will not be easily overcome. This is the first time a government agency has come clean on CCS and shown it not to be the panacea for greenhouse gas regulation, as it is often painted by opponents of coal-fired power generation.
The Weak Link
Many opponents of coal-fired generation have intervened in recent plant regulatory permit hearings touting CCS as a “tried and proven technology” that should be written into permits as best available control technology for CO2 control. In a minority of instances, regulators and the courts have agreed. The GAO report injects a large dose of reality into discussions that often deliberately mischaracterize the commercial status of CCS technology. CCS has many major hurdles to clear before the combined technology is ready for prime time.
The GAO report correctly states that CCS is much more than just figuratively sweeping the CO2 under a rug. CCS is composed of five distinct process steps: capture carbon and compress it into liquid CO2; transport the liquid CO2 to a storage location; inject and store it deep underground; monitor it over the long term to verify that the CO2 stays put, and conduct remedial measures in case leakage occurs. Each of these steps has its own technology challenges, risks, development schedule, and cost implications. The chain fails when the weak link fails.
I observe that most of the current work on CCS revolves around the capture and compression technology portion of the CCS chain, followed by some work on geology and minor pilot injection tests. Virtually no significant work is under way on interstate or cross-border CO2 pipeline issues (it takes a decade or more to permit an interstate natural gas pipeline), monitoring and leakage characterization, or remediation plans when, not if, a CO2 leak occurs. The general public is unable to grasp the details of nuclear technology after decades of discussion, so why should CCS be different? It will only take a single CO2 leak that kills a forest or turns a valuable aquifer into sparkling soda water to turn the public squarely against sequestrating CO2 .
No Operating Plants
When the GAO asked about commercial installations of CCS technology, none could be found. The only large-scale example is the German oxyfuel boiler that was recently commissioned, although it is more accurately described as a pilot plant.
In the context of adding CCS to new integrated gasification combined-cycle (IGCC) plants, the GAO report notes that, “The cost of electricity production would increase by 35% for newly constructed IGCC plants with CO2 capture, compared to a 77% increase for newly constructed pulverized coal power plants equipped with CO2 capture.” To their credit, the GAO report authors go on to chide the Department of Energy for its hyperfocus on IGCC carbon capture and call on it to pay more attention to the technology challenges and costs of retrofitting our existing fleet of coal-fired steam power plants. “The outlook for widespread deployment of IGCC technology is questionable and the agency’s [DOE] funding related to IGCC technology has substantially exceeded funding for technologies more applicable to reducing emissions from existing coal-fired power plants.”
The cost of retrofitting conventional plants will clearly be much higher than installing a CCS system on the tail pipe of an IGCC plant designed as a greenfield project. To put these costs into perspective, American Electric Power’s recent estimates for its 600-MW IGCC plant planned for Ohio is $2 billion—and that plant is described as just carbon capture capable.
Fouling Water Supplies
Beyond capturing CO2 are more cost and regulatory uncertainties yet to be thoroughly evaluated. The GAO report continues by noting that “Key regulatory and legal issues will need to be addressed if CCS is to be deployed at commercial scale. Among these issues are: Confusion over the rules for injecting large volumes of CO2 , long-term liability issues concerning CO2 storage and potential leakage, and how property ownership patterns may affect CO2 storage.”
The EPA is charged under the Safe Drinking Water Act with protecting the public health by preventing injection of any agent that will endanger underground public drinking water sources. “However,” the GAO report says, “the injection of CO2 for long- term storage raises a new set of unique issues related to its relative buoyancy, its corrosiveness in the presence of water, and large volumes in which it would be injected.” Water that contacts CO2 will form carbonic acid that can eat away rocks over time and possibly compromise valuable water supplies.
The report continues by noting, “it is likely that thousands or tens of thousands of injection wells would need to be developed and permitted in the U.S.” In July 2008, the EPA posted a proposed change to the Safe Drinking Water Act “that well operators remain responsible indefinitely for any endangerment of underground sources of drinking water.” The EPA is clearly concerned about the public health effects of pumping vast quantities of CO2 into the earth and the unintended consequences of that pumping.
The GAO report also noted that is unclear whether current hazardous waste disposal laws apply to CO2 storage facilities: “RCRA (Resource Conservation and Recovery Act) and CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act—the superfund cleanup regulation) could pose similar complications for CCS projects. RCRA authorizes EPA to establish regulations governing the treatment, storage, and disposal of hazardous waste. A hazardous waste is generally defined as a solid waste that either exhibits certain characteristics (ignitability, corrosivity, reactivity, or toxicity) or has been listed as a hazardous waste by EPA.”
You might respond that CO2 has not been found to be a hazardous waste by the EPA and therefore these draconian clean-up regulations don’t apply. The GAO also addressed this “loophole” by noting “the [EPA] rule’s preamble cautions that injected CO2 streams could contain hazardous constituents that would make these streams ‘hazardous.’ ”
Prepare for a Double Standard
This sidesteps the obvious question: If CO2 is reclassified by the EPA as hazardous so it can be regulated within the confines of the Clean Air Act, then most clear-thinking people would not suggest storing it in the ground and risk polluting the earth beneath our feet or our shrinking aquifers and subsurface water supplies. However, I’m sure some regulator or congressional committee will figure out a way to certify CO2 as hazardous when it is in the air but benign when it has “contaminated” our drinking water.
—Editor-in-Chief Dr. Robert Peltier, PE