Update: 12.3 kW Solar System

[jebatty]

2020 continues on a track of record high kWh for our solar PV system in northern Minnesota. After a dismal all-time record low month of January with 473 kWh vs January average of 710 kWh, 2020 has beat the 5 year average every month February through July, with July setting an all-time record high of 1950 kWh vs July average of 1795 kWh and the prior all-time high of 1923 kWh in July 2014. With five months yet to go in 2020, the record setting production has plenty of time to reverse course ... or set a new high record year.

I'm using the 5-year period 2014-2018 as a fixed average with the thought that this time period should reflect production with least impact of any panel degradation, and that over time panel degradation should start to be evident. I believe that degradation of 1/2 of 1% per year is an industry standard. After nearly 7 years I don't see any degradation trend.

 

[DuaeGuttae]

Thanks for sharing this, jebatty. I actually just reread your 15-page thread on your original and enlarged installation. We’re looking at our solar options here in sunny Texas, and I’ve been reading past threads. I appreciate the insights you share and the questions and comments others provide.

 

[ABMax24]

That's actually pretty impressive. This is our second year of production and we still don't have a noticeable drop in output. Although my last couple months data is inaccurate as Neurio was bought by Generac and my energy charts don't line up with my power charts and I can't seem to get Generac to understand the problem let alone fix it.

Is there anything you'd do different if you did it again? Would you still go with micro-inverters or would you choose a string inverter?

 

[jebatty]

Is there anything you'd do different if you did it again? Would you still go with micro-inverters or would you choose a string inverter?

I would have installed initially the maximum kW array that I could backfeed to the grid under net metering. At least I had the foresight when installing the first 26 panels in 2013 to install underground wiring to allow a 20 panel expansion in 2015 which brought me to that maximum.

I also think I would have gone with string inverter(s). My micros are no longer made, but I did buy a few extra to replace a couple of possible future failures. Still, I have had just shy of 7 years of trouble free performance (except one micro failed early on, a 10 minute job to replace). String inverters and panels with optimizers seem to have greatly improved, and it doesn't seem that micros are a major player in the PV arena.