A newly released National Energy Technology Laboratory (NETL) study details the cost to retrofit America's coal fired power plants with equipment to capture carbon dioxide emissions.
The study is entitled Coal-Fired Power Plants: Costs of CO2 Capture Technology and Improvements in Efficiency. The 50 page study was released in December 2009 and gives a cost breakdown by component and system for setting up a carbon capture plant at pulverized coal power stations.
Given the importance of coal to power generation in the United States, where coal-fired power plants supply almost 50 percent of the Nation’s electricity needs, examination of the costs and practicability for retrofit of existing pulverized coal power plants with CO2 capture technology is a valid exercise.
To help elucidate this issue, this study defined a viable population of pulverized coal plants, which were examined individually to determine costs and space availability for retrofit. The effort was designed to assess coal-fired power plants in the U.S. relative to the cost and feasibility for retrofit with CO2 capture technology.
The study comprised the development of a database and geographic information systems (GIS) modeling analysis of coal-fired power plants in the U.S. to conduct the assessment.
The viable population for the analysis was defined as those active plants with a combined unit generation capacity greater than 100 MW, an average heat rate below 12,500 Btu/kWh, and a location within 25 miles of a potential carbon sequestration opportunity. The resultant population totals 738 units located in 324 plants with a total generation capacity of 282 GWs. The units were then evaluated individually.
The analysis is based upon the NETL 2007 publication Carbon Dioxide Capture from Existing Coal-Fired Power Plants (Conesville Study) as a foundation for the application of carbon capture retrofit technology in terms of cost and layout. Absolute costs for each generation unit were calculated then levelized in terms of cost of post-retrofit electricity, cost per tonne CO2 captured, and cost per tonne CO2 mitigated. The analysis, like the Conesville Study, assumes constant coal. That is, plants will not burn more coal to generate the make-up power associated with the parasitic load of the retrofit.
Central to the analysis is the quantitative GIS model, entitled the Carbon Capture Model (CCM). The CCM comprises programmatically linked databases, GIS map documents, and report spreadsheets that calculate capital expense (CAPEX), operating expense (OPEX), and parasitic load associated with retrofitted carbon capture technology. The model evaluates these parameters by scaling costs using the plant-specific parameters and algorithms derived based upon the Conesville Study. A GIS imagery analysis of each plant was conducted to modify construction costs due to specific site requirements by assigning construction difficulty factors to retrofit components. Cost-supply curves relative to the viable population were developed.
Results of the CCM analysis modeled at an 85 percent capacity factor without make-up power indicate that, for the 10th percentile (28 GW) of the analyzed viable population, the total levelized CO2 capture cost would be about $15/tonne or less. The 50th percentile (137 GW) of the analyzed viable population can be retrofitted with a total levelized CO2 capture cost of about $25/tonne or less. To retrofit 90 percent of generation capacity (about 247 GW), the total capture cost would be about $40 per tonne or less. These costs do not include make-up power and are therefore significantly less than those calculated in the Conesville Study.
The figure shows the U.S. Population of Coal Fired Plants.
