Here are some screenshots from Google Powermeter that show the net electricity consumption (consumption – generation) for the duplex and the solar generation as well. Unfortunately, the TED5000 that is installed in the circuit panel is not terribly accurate and seems to be bothered by some of the fluorescent lights in the duplex. The device overestimates the solar generation by a significant amount and depending on when a fluorescent light is turned on, it may over or underestimate the house electricity consumption. In other words, these graphs can give us a general idea of how the house is performing, but the data should not be considered robust. The monthly data from the EnPhase units are also displayed as a comparison for the solar generation numbers.
May 2010 Net Consumption: -32 kwh
May 2010 Solar Generation: 520 kwh
Enphase May 2010: 487.98 kwh (difference of ~32 kwh)
June 2010 Net Consumption: 330 kwh
June 2010 Solar Generation: 510 kwh
Enphase June 2010: 420.48 kwh (difference of ~90 kwh)
Obviously May was a milder month than June, resulting in much lower energy usage, but it is still kind of crazy to see such a huge jump. I think that Brian and I were able to keep the AC off for most of May, and then we succumbed to the luxury of mechanically cooled air in June. May was a little better solar month as well–lots of rain in June. I will post July numbers soon, but July looks to be much better than June, which can be explained by the fact that the lower unit has largely been unoccupied during July. I’ll also put these numbers into perspective a bit.