So how bad are string inverters vs microinverters?

[SunEagle]

I would say microinverters are better because they function in a parallel circuit.

There are good and bad points when to consider micros or string inverters.
Each person needs to understand what they are getting and how much it costs them. As long as the decision to go with micros is not the seller's hard push because most people don't need the micros and their system will work just fine with a string.

[jflorey2]

I would say microinverters are better because they function in a parallel circuit.

In specific cases (radically different insolations/temperatures/panel types) yes. But as has been mentioned in this thread dozens of times now, there are many cases where a string inverter is just plain simpler, cheaper and more reliable.

[J.P.M.]

I would say microinverters are better because they function in a parallel circuit.

Can you elaborate on the thinking that led you to that opinion ?

[solarix]

I think by parallel, he is saying that if one fails - it doesn't affect the others as opposed to a series string where one failure would affect the whole string. While I go along with that systems analysis in general, my thinking on this issue is that solar is different. Solar PV panels are incredibly reliable and a string of them in series virtually never fails. Even from a shading efficiency viewpoint, string inverters have been proven to be as good as individual optimized arrays except in special situations. Would you rather have a super reliable system with limited visibility into failure modes, or a system with a much higher risk of failures but those failures are easily identified? I'll take the high rel system any day.
I contend that putting electronics in a hostile environment like under a roof mounted array is just asking for trouble...

[nomadh]

I think by parallel, he is saying that if one fails - it doesn't affect the others as opposed to a series string where one failure would affect the whole string. While I go along with that systems analysis in general, my thinking on this issue is that solar is different. Solar PV panels are incredibly reliable and a string of them in series virtually never fails. Even from a shading efficiency viewpoint, string inverters have been proven to be as good as individual optimized arrays except in special situations. Would you rather have a super reliable system with limited visibility into failure modes, or a system with a much higher risk of failures but those failures are easily identified? I'll take the high rel system any day.
I contend that putting electronics in a hostile environment like under a roof mounted array is just asking for trouble...

But thats where this thread took a turn for me. I agreed with you on the simplicity but now I hear the new regs require you to have per panel electronics for shutdown. Maybe still not as complicated as a microinverter but at this point if you must have per panel electronics and the inherent unreliability this would push me towards microinverters and the per panel info I could get from it.