We have had our grid-tied 7.5kW array for a little over a year and a half. I looked at the stats randomly this morning and it has recorded 18.8 MWh produced.
Granted this was installed by a contractor (I had no desire to be installing 400W panels on my 2 story roof by myself!) So my ROI isn't as fast as a total DIY, but it is still resulting in saving a good chunk long-term.
Granted this was installed by a contractor (I had no desire to be installing 400W panels on my 2 story roof by myself!) So my ROI isn't as fast as a total DIY, but it is still resulting in saving a good chunk long-term.