Carbon Capture and Storage

Coal is a major contributor to US carbon dioxide (CO2) emissions. In 2005 the US emissions from fossil fuel energy production were approximately 5.9 billion metric tons of CO2. Coal is responsible for approximately 2.1 billion metric tons of CO2 emissions or approximately 36% of US total CO2 emissions[i].

Given coals position in the US energy portfolio any attempts by the US to pursue significant reductions of CO2 emissions will require a solution for coal fired power plants. Carbon capture and storage (CCS) presents a viable approach to significantly reducing overall US CO2 emissions through the capture of CO2 from large point sources and the storage of CO2 in geological formations rather than the release of CO2 into the atmosphere.

CCS represents an attractive and viable approach to reducing CO2 emissions because:

• The technologies/ methods for carbon capture at source points and transportation currently exist and can, in some cases, be retrofitted to existing power plants
  The technologies/ methods for carbon capture are capable of removing 90% to 99.9% of the CO2 emissions produced by source points[ii]
• The source points of CO2 emissions are highly concentrated allowing for a more manageable roll-out of CCS solutions, when compared to the application of new technologies for mobile CO2 emitters such as the millions of automobiles currently on US roads. Of the total CO2 emissions resulting from electricity generation approximately 2.1 billion metric tons, or 49%, originated from approximately 1,715 large CO2 point sources.”
• The 100 largest CO2 point sources account for 39% of total annual CO2 emissions; 79% of these are coal fired power plants. The 500 largest CO2 point sources (29%) account for 82% of annual emissions; 78% of these are coal fired power plants”[iii]
• The abundance of geological formations across the US which are theoretically capable of storing carbon and the proximity of storage reservoirs to major CO2 source points. “Formations studied to date contain an estimated storage capacity of 3,900 GtCO2 with some 230 candidate geologic CO2 storage reservoirs”[iv]. Moreover, 95% of 500 largest CO2 point sources are within the 50 miles of candidate reservoirs[v]
  

Challenges facing the adoption of CCS include:

• The existing technologies/ methods involved carbon capture have not been applied on the commercial scale required for the electricity generation industry
• The high cost of building/ retrofitting power plants with carbon capture technology along with the reducing in power plant efficiency due to the energy requirements of carbon capture technology. Ultimately, these costs are passed onto the consumer in higher cost of electricity when compared to existing coal fired power plants
• The investment in a US wide carbon transportation infrastructure required to apply CCS on a commercial scale required for the electricity generation industry

[i] Annual Energy Outlook 2008 (Early Release), Energy Information Administration 2008
[ii] The Future of Coal, Massachusetts Institute of Technology 2007
[iii] Carbon Dioxide Capture and Geologic Storage, Global Energy Technology Strategy Program 2006
[iv] Carbon Dioxide Capture and Geologic Storage, Global Energy Technology Strategy Program 2006
[v] Carbon Dioxide Capture and Geologic Storage, Global Energy Technology Strategy Program 2006