As module and inverter efficiencies start to peak, solar developers and designers must turn to new tactics to squeeze more energy from new and existing PV installations. Beyond augmenting solar harvest in both sub-optimal and ideal conditions, module-level power optimization allows collection of system performance data at a level of granularity previously unseen. New module-level data collected from more than 15 MW of commercial PV systems installed in real, operating conditions quantify and reveal new points of system performance degradation. Analysis of this unprecedented data set show new opportunities for PV developers, designers and maintenance teams to improve system output and power plant design.