I'm surprised at the 40¢ figure for utility scale. Are you sure that didn't include the mounting hardware? Utility-scale PV is typically with 1-axis trackers.
Another possibility would be that utility scale solar optimizes to a much large disparity between DC rating and AC rating than does domestic rooftop PV.
Wait, so those were not US residential cost figures you quoted? Because I don't see how they'd allow Chinese imports for only residential installation.
Another possibility would be that utility scale solar optimizes to a much large disparity between DC rating and AC rating than does domestic rooftop PV.