premise: These estimates do not take into account any synergies or efficiencies realized from retrofitting multiple units on a site, as are described in Section 2.5 and 3.5, or from a combination of technologies, as described in Chapter 5. Roughly 50 percent of an SCR project man-hours and 40 percent of an FGD project man-hours are for boilermakers.
hypothesis: These synergies created by multiple retrofits can save as much as 40%.