Thanks to Net Metering, I’ve managed to sell an average of 10% back to the utility throughout the year. This occurs any time when I’m generating more electricity than the house is consuming, so excess is returned to the grid at the same rate I’m billed for it.
The daily average over twelve months was roughly 21 kWh each day with a standard deviation of about 7.8. The best two week period was the February / March border. Between February 25, 2010 and March 10, 2010, I had seven of my top ten days and averaged 27.29 kWh. The best day on record was March 4, 2010; the system generated 34.12 kWh. Mid-March to Mid-April 2010 saw a number of clear, cool, sunny days, and I sold 25% back to the utility during this time.
All told, the data I’ve collected suggests my installation has accounted for 35% of my electricity over the past year.