micro inverter off grid system buying guide
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Rednecktek
Solar Wizard
Microinverters and off-grid are pretty mutually exclusive. The microinverters need the grid to sync up with and control whereas off-grid has no grid for them to sync to.
There are ways through dark magic and Beanie Baby sacrifices to make your own grid to get the microinverters to sync to, I believe it's called AC Coupling, but by the time you've got the panels all configured and mounted to create the power system for your microinverters to sync to, why spend another $50+ ea per panel on a second complete array?
There are ways through dark magic and Beanie Baby sacrifices to make your own grid to get the microinverters to sync to, I believe it's called AC Coupling, but by the time you've got the panels all configured and mounted to create the power system for your microinverters to sync to, why spend another $50+ ea per panel on a second complete array?
DIYrich
Solar Wizard
Enphase iq8 with the right equipment will work grid down.
timselectric
If I can do it, you can do it.
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And the right size bank account. lol
Solar Guppy
Red Cobra Guppy
Arguably the wrong tool for the job ( offgrid ) and less cost effective if actually cobbled together to function ( AC Coupling ).
What is more “cost effective” in your opinion?
Solar Guppy
Red Cobra Guppy
Depends on the NEC code designing too.
By far, string inverters are the lowest cost per watt, so if one is NEC2017 or older ( no module level requirements ).
Once you are in NEC2020, its module level required shutdown, then the math is different as something has to be there, but even in this case its $30 rss only module vs $165+ for micro inverters, so more than 10 panels, string configuration still wins.
Most hybrid inverters have ample capacity for most systems ( like most things nothing is one size fits all ), so just adding panels with RSS is the best option.
timselectric
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The main reason for AC coupling is to use an existing grid-tied system for a new off grid setup.
Or if you have maxed out the DC side of a hybrid AIO.
But grid-tied and off grid batteries, can also be problematic.
Or if you have maxed out the DC side of a hybrid AIO.
But grid-tied and off grid batteries, can also be problematic.
And shading if you want to use optimizers adds cost. Cabling/wiring can be cheaper with micro inverters.
I’m paying less than $100/panel to add micros. That would work out to be ~$167 if I instead added another Sol-Ark 15K and that’s before RSD/Optimizers or figuring more cabling into the equation.
You can easily use microinverters to supplement an off-grid system. Andy posted a video in Off Grid Garage. I have a cheap 300W gti plugged into mine. Just wanted to see if it works. Also means I'm running AC thru 30m of cable instead of DC. Less voltage drop and simplifies the wiring.
timselectric
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If you are connecting it to an AC coupling capable system.
Solar Guppy
Red Cobra Guppy
If the loads are lower than 300W ( or lower than the inverter is pushing to grid ) in your example, there would be issues, you need an AC coupling certified inverter ( frequency shift derating ) or things could go badly.
cs1234
Solar Wizard
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Where are you getting micros for less than $100/panel to couple with your Sol-Ark? What ones are you using? I like the idea of UL listed micros just to avoid the code requirements and safety issues for high voltage DC.
Bluedog225
Texas
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I looked around at his videos. Great resource. But I don’t see a vid one off-grid micros. Could you link? Thanks
timselectric
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They are not "off grid" micro inverters.
They are regular micro inverters, connected to his off grid Garage. His system can AC couple.
timselectric
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Micro inverters are designed for grid-tied.
They just produce all that they can and force it into what they are connected to.
They expect to be connected to an infinitely available place to push their power.
When not connected to the grid. They must be connected to something that can control their output (AC coupling).
Rednecktek
Solar Wizard
I've never figured out how that works with AC coupling. I know in the regular world the SCC just draws less power when the batteries are full, but microinverters are full-bore-full-time? Is that like the wall outlet analogy?
(For the newbies here... yeah... asking.. uhhh.. for a friend... yeah..)
(For the newbies here... yeah... asking.. uhhh.. for a friend... yeah..)
