**I am interested in part of the Solar resource and scaled data. I do not understand how HOMER scales data with Graham algorithm, more exact, how it knows how to scale hourly data? And if you could me explain a little more about graphs of scaled data PDF, scaled data CDF, and scaled data duration curve.**

HOMER scales hourly solar radiation data in a very simple way. If the annual average of the original data is X kWh/d and you wish to scale it so that it averages Y kWy/d, HOMER multiplies every hourly value by Y/X.

The PDF graph of the scaled solar resource data plots how frequently the data falls within certain ranges. The CDF plots how frequently it falls below certain values. (The CDF is the integral of the PDF.) The duration curve is the CDF with the axes transposed.