Apparently, according to EarthScience.SE, the measurement of how "bright" a given day is, is measured in units of
kWh/m^2, known simply as "solar radiation". Apparently, 3 kWh/m^2 is the average brightness of an American summer day (useless fact).
This solar panel claims an output of 6V at 330mA. Obviously, solar panels will not perform the same on cloudy, darker days.
What I'm looking to do is to put together an equation/algorithm that will take solar power (in Watts) and solar radiation ("brightness"; in kWh/m^2) as input, and tell me what the adjusted power output is for that panel, based on the current brightness.
As an example, using that particular solar panel and a given point in time when, say, there is only 2 kWh/m^2 of solar radiation in the given vicinity, then the equation might yield something like this:
// Example only AdjustedPowerOutput(normalOutput, solarRadiation) = normalOutput * (solarRadition / 3) = 1.98 Watts * (2 kWh/m^2 / 3 kWh/m^2) = 1.98 Watts * .667 = 1.32 Watts
So, if this equation was correct, at that point in time in the given day, the panel will only output 1.32 Watts.
How can this "adjusted power output" actually be calculated?