Solar Performance - September 2015

September was a rough month for my solar panels. On several days the inverter failed and shut down, which meant no power was produced. In the last 10 days of the month the monitoring and control unit for the individual panels also froze, reducing efficiency (and giving me some holes in my data).

Compared to last month production was down significantly, but luckily so was my use. That's likely because I was out of town for about a week, visiting Portland for one weekend and spending several days in Chicago at the end of the month.

In comparison to September of last year things aren't quite as bad. Production and use were both down by similar amounts, so my surplus sent to the grid was about the same.

The full-year numbers continue to look good despite this month's setbacks, still slightly ahead of estimates and with a significant surplus sold to City Light.

Individual panel performance was remarkably consistent this month. Perhaps this is due to the optimizing units being out of commission for 10 days, or perhaps the weather was more stable throughout the day.