I'm going to say it's been hot, and we've been using the air conditioning a lot. For grins, here's the year's data from the TED5000 (it's not exact, but it's close enough):
Green is used, blue is generated, purple is the difference :o)
Here's the data for just August 31st, hour by hour:
Not bad, eh? From 8am to 3pm we generate more power than we use.
Of course, the temperature doesn't peak until ~4pm:
OK, I need to get out more.