To see real world expectations of flat mounted solar panels: Enter a few basic parameters below about location (Latitude), date, time, watts, voltage and amps.

A few notes about the calculator:

• The current version (1.0.1) makes the following assumptions:
  • Horizontal panels
  • A clear, cloudless sky
  • No other obstructions to shade the panels
  • A basic, non-current-boosting charge controller
  • The northern hemisphere
  • Panels at sea level
• It accounts for the following variables:
  • Length of day, based on latitude and date
  • The elevation angle of the sun throughout the day, also based on latitude and date, as it affects the quantity of direct solar radiation (the Cosine Effect)
• It ignores the following variables: [hopefully, some will be included later]
  • Air mass due to altitude
  • Angular air mass
  • Angular spectral variation
  • Angle of incidence effects (apart from pure Cosine Effect)
  • Diffuse solar radiation
  • Temperature
  • Anything else I haven't mentioned