Definitions for "Peak Watt"
The maximum amount of power produced or demanded in a time interval, measured in watts.
A manufacturer's unit indicating the amount of power a photovoltaic cell or module will produce at standard test conditions (normally 1,000 watts per square meter and 25 degrees Celsius).
The maximum nominal output of a PV (solar) device, in Watts (Wp) under standardized test conditions. (usually the most favorable!).