Solar Panel Surface Area: Total Array Area for PV panels.
Size (kW) = Array Area (m2) * 1 kW/m2 * Module Efficiency(%). The above equation is used by National Renewable Energy Laboratory (NREL) to define the grid size.
The array area and the module efficiency can be inputted in 'Solar Panel Surface Area' and 'Solar Panel Module Type' in cove.tool.
Cove.tool provides provides a predictive input for PV loads with its energy analysis for schematic design stage. To get a detailed accurate information about PV system for your final design, definitely talk with a qualified PV consultant or use tools like PVsyst, Helioscope and System Advisor Model (SAM) that are specifically designed for PV design and analysis.