3.2 New methods used in the 2011 update
A change to the methodology occurred in the adjustment of process parameters of heat rate, CO2 emissions and CO2 capture according to regional coal composition and emissions requirements. This resulted in changes to the capital and operating and maintenance (O and M) costs for the capture facilities. This change improved the granularity of the estimates and analyses for the discrete regions given that:
- process design for coal-fired facilities is strongly dependent on local conditions including fuel composition, emissions regulations, climate and availability of water for cooling;
- design impacts sizing of equipment and thus capital costs;
- the heat rate of facilities increases with decreasing coal rank (heating value), therefore this increases the amount of fuel required and potential change in fuel costs; and
- the CO2 emission intensity change relates to changes in fuel, potential impact on cost of CO2 capture and avoided.
The adjustment of the process parameters was undertaken by:
- conducting a literature/study review of facility designs with different coal ranks;
- determining the heat rate and cost trend variations from reference coal designs. Trends described as simple functions from reference coal composition (Pittsburgh No. 8); and
- the adjustment of the capture technology costs at the reference location and then moving these to the region of interest.