Using rooftop grid-tie solar during a power outage.

[JackFlorey]

I am thinking of putting a splitter between the panel and the micro inverter for one of the panels to provide a way for me to access some dc power directly from a single panel during a power outage.

Enphase sells a system that will isolate your panels from the grid and allow you to island them safely, and then run off the power provided. You'd need their isolation switch and at least one battery.

If you want to do something with DC power, I'd recommend just getting a few more panels and setting up a completely separate system. Panels are so cheap these days that it's not worth it to mess around with your existing (working) system.

 

[ZeroEm]

Thanks. When the power goes off I can turn off the main breaker at the panel. That will prevent the microinverters from turning back on while I am tapping into dc power. (Is it a good idea to turn off each individual breaker as well when I do that and then turn them back on one by one? Is that the best practice?)

Although if the micro inverters did turn back on while I was drawing dc power from one panel, I believe that the system would just think that one panel is not working well, exhibiting low voltage. Maybe not that different from if it was in the shade or covered with leaves. I'm not sure, but that would be my guess? (Or maybe it could oscillate? I'm not sure how the MPPT aspect (of the micro inverter) would respond to this situation.

PS. I am thinking that for the dc charging I might use, for example, a Victron Phoenix dc-dc converter that accepts 20 to 40 volt input and puts out 14.2 volts during bulk charging... I will have to research that. I'm not sure what they have or what the exact voltage range of my panel is.

Let us know how it turns out!