A CO2 STORAGE SUPPLY CURVE FOR THE UNITED STATES: ADDRESSING COST, SCALE UP AND GEOLOGIC UNCERTAINTIES.

Capturing and storing carbon dioxide (CO2) in geological saline water-bearing formations may represent an important option for managing CO2 emissions. Fossil fuel-based power plants accounted for approximately 40% of all CO2 emissions from the United States in 2008 and therefore represent an important factor to address atmospheric CO2 emissions. Once captured, CO2 storage in geologic formations represents a potential scale-appropriate solution. Depleted oil and gas reservoirs, un-mineable coal seams, and deep (>2,500 feet) saline formations are being explored as targets for large scale geologic storage of CO2. Of these, deep saline formations may represent the largest potential sink. The national-scale version of the Water, Energy and Carbon Sequestration Simulation Model (WECSsim © ) presents the engineering and cost uncertainties involved with scaling up CO2 capture and storage (CCS) at the national level while accounting for the substantial uncertainty with specific geological parameters. This paper presents the ranges of costs for CCS due to variations in plant type, capture technology, and geological storage formation uncertainties. Several national-level CO2 storage supply curves were developed to illustrate how sensitive both storage costs and storage volumes are to engineering, economic and geologic performance assumptions. Initial results indicate the avoided cost of CO2 for the U.S. range from 82 to 136 $/tonne for 1 gigatonne (Gt) of CO2. These costs correspond to cumulative annual emissions reductions of 1.5 to 0.6 Gt of CO2 per year at $100 / tonne. Competition for storage space between power plants, limiting the distance power plants can send their CO2 to alternate saline formation for storage, and whether to extract H2O from saline formations to alleviate pressure build up from the CO2 all affect the supply of storage space, and therefore the overall systems’ costs.