That NREL data is full of loose stool.
I know of at least 12MW installed just in the Chicago area.
I agree on that, but their $/W numbers are right on, in fact current Average $/W numbers should ALWAYS be lower than theirs since theirs are an average of all projects since they started tracking.
Florida numbers are off the chart, no wonder no one wants to do PV there..... I'm sure the data can be skewed since some projects have incomplete data, but I can't imagine what the $/W number(s) were for the projects that skewed it THAT badly.
Our numbers for 500kW to 1MW jobs have been falling anywhere between $4.75 and $6.50/Watt depending on the modules, inverters, DC scheme (mono or bipolar) and the local crew rates, some areas are absurd (compared to San Diego rates). Module rates are in freefall now with some as much as 30-40% lower $$ than a year ago.