In summary, the total time needed to complete the design, installation, and testing at a typical 500 MWe facility with one FGD unit is 27 months, 32 months at a facility with two boilers being served by a single absorber module, and approximately 36 months at a facility with three absorber modules (six boiler units).
To summarize, it took 27 months to complete the design in that particular way- otherwise 36.