This estimate is supported by the number of orders of FGDs for 2001 and projected orders through 2002 by the electric utility industry, which totals over 11 GWe46, and over 13 GWe of announced scrubbers which are scheduled to start up by 2005.

Does it follow that "This is estimated by, among a plethora of other things, the number of orders of FGDs."?
it is not possible to tell