On the heels of President Obama’s national climate change address, the Department of Interior said June 26 that the nation has massive potential for carbon capture and storage (CCS).
The United States has the potential to store a mean of 3,000 metric gigatons of CO2 in geologic basins throughout the country, according to the first-ever detailed national geologic carbon sequestration assessment released today by the U.S. Geological Survey (USGS).
“This USGS research is ground-breaking because it is the first realistic view of technically accessible carbon storage capacity in these basins,” said Secretary of the Interior Sally Jewell. “If enough of this capacity also proves to be environmentally and economically viable, then geologic carbon sequestration could help us reduce carbon dioxide emissions that contribute to climate change.”
Based on present-day geologic and hydrologic knowledge of the subsurface and current engineering practices, this assessment looked at the potential for CO2 storage in 36 basins in the United States. The largest potential by far is in the Coastal Plains region, which accounts for 2,000 metric gigatons, or 65%, of the storage potential. Two other regions with significant storage capacity include the Alaska region and the Rocky Mountains and Northern Great Plains region, Interior said in a statement.
Technically accessible storage resources are those that can be accessed using today’s technology and pressurization and injection techniques. The most common method of geologic carbon storage involves pressurizing CO2 gas into a liquid, and then injecting it into subsurface rock layers for long-term storage.
This assessment goes further than all previous assessments in considering the viability of sequestration. For example, all areas with groundwater sources that are considered freshwater by EPA standards were eliminated from consideration for carbon storage resource potential in this assessment. In addition, the rock layers included in the assessment were limited to those determined to have sufficient natural seals to prevent CO2 from escaping. This assessment also focused only on rock layers located at depths at which CO2 would stay under sufficient pressure to remain liquid.
Importantly, the study did not evaluate economic viability or accessibility due to land-management or regulatory restrictions for geologic carbon sequestration within these basins.
Most power industry observers say that economic and regulatory uncertainty, not technology, are probably the biggest hurdles to commercial use of CCS.
The Department of Energy’s original FutureGen and subsequent FutureGen 2 proposals have had trouble taking off at a time when natural gas remains inexpensive.