Monte Carlo simulation maybe a good choice to address this issue. You can apply Monte Carlo to numerically simulate the uncertainties which is/are featured by the PDF and then use the Pseudo-random numbers as the model inputs to analyze the possible energy production from photovoltaic under given uncertainties.

The answer is yet. However, it involves math that cannot be easily entered in this response box, so I have attached a description in a Word file.

Just be aware that easily the most significant variable in the estimation of energy from a PV array is the weather conditions. If you are using statistics to model the behaviour of the weather, also note that past weather may no longer be a good predictor of future weather, due to factors like climate change. On the other hand, you can model the behaviour of an array under any conditions you like - just be careful to select those conditions that look more probable given climatic variability.