Blancisimo
New Member
- Joined
- Apr 13, 2021
- Messages
- 1
So I'm at a bit of a sticking point on how to set up a home backup.
I live in an area where the grid goes down at least 4x a year.
I have gas generators I can use when the grid goes down, but obviously this is bad for many reasons.
The house has a decent sized solar grid tie setup which was installed before I bought the home.
The grid tie system uses a SMA Sunny boy (older unit), max vpv = 400V
My goal is to configure a hybrid inverter setup so that when the grid goes down (ideally) the system just kicks in and replaces the grid.
Secondarily (as grid tie seems fraught with $$$ problems), I could imagine using transfer switches to run a few critical loads, basically what I already do with the generator, when the grid drops.
In this case, my idea would be to have enough power to run the internet, possibly TV, and lights at night, and during the day infrequently use the generator (and perhaps feed the solar panel output via transfer switch to this off grid inverter).
So a few questions I can't seem to nail down:
1. Is it true that Growatt split phase systems require 2x sources to properly invert? Sites like this say they do - https://signaturesolar.com/growatt-48v-5kw-450vdc-stackable-off-grid-inverter/ - in that case, the system would not invert the battery charge without having active solar voltage, thus not running any output at night.
2. Is there an alternative option for the above? I'm only looking to output a peak of ~ 18A on a split phase output. Is there an inverter that can run off the batteries when the solar is off?
3. Should I just replace the sunny boy with a sol-ark or similar UL listed grid tie inverter?
4. is there another option I should consider?
Apologies if this question was already asked, I did quite a bit of hunting before putting up my particular situation, but can't seem to figure out a best-case scenario. Thanks in advance for any advice !!
I live in an area where the grid goes down at least 4x a year.
I have gas generators I can use when the grid goes down, but obviously this is bad for many reasons.
The house has a decent sized solar grid tie setup which was installed before I bought the home.
The grid tie system uses a SMA Sunny boy (older unit), max vpv = 400V
My goal is to configure a hybrid inverter setup so that when the grid goes down (ideally) the system just kicks in and replaces the grid.
Secondarily (as grid tie seems fraught with $$$ problems), I could imagine using transfer switches to run a few critical loads, basically what I already do with the generator, when the grid drops.
In this case, my idea would be to have enough power to run the internet, possibly TV, and lights at night, and during the day infrequently use the generator (and perhaps feed the solar panel output via transfer switch to this off grid inverter).
So a few questions I can't seem to nail down:
1. Is it true that Growatt split phase systems require 2x sources to properly invert? Sites like this say they do - https://signaturesolar.com/growatt-48v-5kw-450vdc-stackable-off-grid-inverter/ - in that case, the system would not invert the battery charge without having active solar voltage, thus not running any output at night.
2. Is there an alternative option for the above? I'm only looking to output a peak of ~ 18A on a split phase output. Is there an inverter that can run off the batteries when the solar is off?
3. Should I just replace the sunny boy with a sol-ark or similar UL listed grid tie inverter?
4. is there another option I should consider?
Apologies if this question was already asked, I did quite a bit of hunting before putting up my particular situation, but can't seem to figure out a best-case scenario. Thanks in advance for any advice !!
