Greg Egan's Page

Hi Greg,

Thanks for the information. It is very challenging to find actual performance information on PV arrays in Alaska. Even though one would think that the PV array at the university would be managed to provide as accurate data as possible, from your information it does not appear to be.


My goal was to get a valid correlation between what the NREL PVWatts calculator (http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/) indicates energy production would be, verses what actual performance is. I have a couple of bench test arrays, a 3KW in south central AK and a 500Watt array in the interior. My empirical results show that actual solar production is about 70% of what the PVWatts calculator forecasts production would be but this is just based on a year worth of data. While the summer and spring months are in the neighborhood of what the PVWatts calculator forecasts, late fall and winter array output is negligible and substantially less than the PVWatts calculator forecasts.

Thanks for your input and if you have any good data on actual solar production in Alaska please let me know.