Plug in solar and GFIs

I think another thing to keep in mind that real PV system is not like a steady power source. No real PIPV will likely produce anywhere near the max inverter power capacity for longer than a short time without throttling. An 800W PIPV inverter will likely only produce 600-700W in a real system during peak season for a duration that is likely much shorter than the continuous use time limit (3 hours?) used for UL compliance rating of wires and receptacles.
 
analog8484 said:
I think another thing to keep in mind that real PV system is not like a steady power source. No real PIPV will likely produce anywhere near the max inverter power capacity for longer than a short time without throttling. An 800W PIPV inverter will likely only produce 600-700W in a real system during peak season for a duration that is likely much shorter than the continuous use time limit (3 hours?) used for UL compliance rating of wires and receptacles.
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I think that is incorrect. An inverter with a sufficiently high DC/AC ratio and optimal panel orientation will typically output at its continuous current rating for several hours on a clear sunny day in summer. That's why the NEC requires the continuous 125% factor for output conductors and OCPDs. It may be that a smaller percentage of PIPV systems will actually do that, due to less than optimal panel orientation or exposure, but it's not something that can be counted on from a branch circuit safety point of view.
 
jaggedben said:
I think that is incorrect. An inverter with a sufficiently high DC/AC ratio and optimal panel orientation will typically output at its continuous current rating for several hours on a clear sunny day in summer. That's why the NEC requires the continuous 125% factor for output conductors and OCPDs. It may be that a smaller percentage of PIPV systems will actually do that, due to less than optimal panel orientation or exposure, but it's not something that can be counted on from a branch circuit safety point of view.
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Sure if the DC/AC ratio and orientation were all optimal then the peak output could be achieved. However, based on my own experience and observations of others (including systems on pvoutput.org) I really see that for most residential systems. I understand ratings compliance can't count on such factors and I was just commenting on the difference between likely reality vs theoretical worst case scenarios.
 
analog8484 said:
Sure if the DC/AC ratio and orientation were all optimal then the peak output could be achieved. However, based on my own experience and observations of others (including systems on pvoutput.org) I really see that for most residential systems. I understand ratings compliance can't count on such factors and I was just commenting on the difference between likely reality vs theoretical worst case scenarios.
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Did you mean "rarely"?
 
jaggedben said:
Honestly my biggest worry about plug-in solar, especially at scale, is not electrical. It's loose solar panels flying around in windstorms.

(And yes, I'm a bit resentful because of all the engineering we have to provide to get approval for some rooftop solar. But installing to standards should ensure the panels stay on the roof.)
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That’s a fair concern. Loose panels in strong winds could definitely become a hazard if they’re not mounted properly. I think the key difference is proper installation and following building standards. When rooftop systems are installed with the right mounting hardware and wind-load calculations, they’re designed to handle pretty extreme weather. So the standards and approvals might feel like a hassle, but they do help make sure everything stays safely in place.
 
Christopher Andrews said:
That’s a fair concern. Loose panels in strong winds could definitely become a hazard if they’re not mounted properly. I think the key difference is proper installation and following building standards. When rooftop systems are installed with the right mounting hardware and wind-load calculations, they’re designed to handle pretty extreme weather. So the standards and approvals might feel like a hassle, but they do help make sure everything stays safely in place.
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The problem is that while rooftop PV module mounting systems are thoroughly engineered, tested, installed by contractors, and sometimes inspected, Joe Bob apartment dweller attaching a module to the outside of his 10th floor apartment balcony railing does not have to meet the same standards and these modules will probably become detached in a wind storm.
 
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