PV Performance Data
At least some preliminary... updated December 11, 2005

    Notes:  The PV performance is tracked every day two ways. First I record the generator meter value every day to get a very accurate kWh/day production value. I also log the minute-by-minute output of the inverters through their serial ports. That value overestimates the actual by as much as 33%. I use that rather to compare the two arrays.
 
This is a figure from the spreadsheet that Michael at Array Technologies provides showing shading at 2:00 pm December 21.
This can be compared to some of the photos of the shading.
Figure predicting shading
This graph shows the running producion in kilowatt hours per day. The red line is the cumulative average daily production, the blue graph is the running average of the last 10 days.
Graph of running average kwh production
This is a graph of the daily producion (from the REC meter) compared to the solar radiation as recorded at the RAWS station near the house. This RAWS station is linked from the home page.
kwh produced vs net radiation
Lastly over a week I did a "fixed vs. tracking" experiment which is reported here (pdf file).