[strkomis]

I am trying to make a solar radiation data logger my self based on Arduino.
I have read all this interesting topic, its a great job you all have done.
I have a question.
Of course one should use a poly-crystaline PV cell as measuring device and not a thin film based one (amorphous or CIS or other type), however poly PV cells are strongly influenced by temperature:
Power output is about -0.45% per Celsius degree above 25 oC and voltage output is about -0.35% per oC above 25 oC. And off course the temperature is the temperature of the cell, not the ambient temperature. Normally the temperature could be 65 oC during a sunny day.
How this is can be compensated?
The error that is inserted is relatively high to my opinion.
Thanks