I’ll try to keep this page updated every month with our solar power production and compare it with the PVWatts estimate of expected generation. For more details about our first solar system (6.93kW of panels, 6kW inverter), visit my blog post about finding solar installers in Charlottesville. At the end of December 2016 we added another 9.425 kW, which got grid connected in Feb 2017. We also upgraded the old system to have online monitoring so now I don’t need to keep visiting the inverter to collect this data.
For a more detailed financial analysis of solar production in Virginia, see my post on that at my other blog. There is a slight discrepancy between the solar inverter numbers and the dominion solar generation meter, which also I’ll keep track of. After installing the new system, this discrepancy grew a lot. I got the Dominion meter tested and it is only off by 0.4% (supposedly it can be legally off by upto 2%). So the old meter (PowerOne) is reporting production accurately (off by exactly 0.4%). The the new inverter (Solaredge) is significantly (6.9% between Feb 2017 to Nov 2017) over-reporting it’s power production.
|PVWatts Old System Estimate||505||425||675||695||742||689||705||661||581||731||473||490|
|New System Estimate||505||425||675||695||742||689||705||661||581||731||473||490|
|2017 (Old Inverter)||312||582||884||859||798||922||873||867||783||738||531||418|
|2017 (New Inverter)||551||996||999||1029||1220||1150||1058||891||777||484||377|
April 2014 was the first full month of production. * First system went live March 19. So March 2014 production numbers represent a partial month. New system went live Feb 8 2017.
Cumulative Power Production as of Dec 31 2017: 41377 (at dominion meter), 42048 (as measured by inverters)
The chart below has not yet been updated since the new system. Once I figure out a good way to do it, I’ll update.