Alright, I've done a bunch research and talked to both Tesla and SolarEdge. Basically there are two routes for new solar and powerwall installations and I'm not really sure which is best. So, I've created a poll and also welcome any thoughts or input. I'm describing these options as AC and DC coupled but please read the descriptions below for full details.
Note that I plan on installing two powerwalls. This is what makes the decision between these two configurations hard for me. If you need more than two powerwalls, it's an easy decision (go with AC coupled powerwalls).
DC Coupled:
Powerwall Type: DC (still available despite what some Tesla reps say)
Compatible Solar Inverter: SolarEdge StorEdge
Controller Interface: SolarEdge cloud interface. EX:
Pros:
More efficient - DC batteries charged from DC solar
Auto-transfer switch allows for only critical items to be powered when the grid is down. See diagram in attached PDF
Less hardware overall (StorEdge inverter does everything)
One interface for everything
Cons:
The StorEdge inverter only supports two Powerwall 2 units. This is only a partial "con" though. Additional powerwall units *can* added but they'll require separate StoreEdge interfaces. If you have a
AC Coupled:
Powerwall Type: AC
Compatible Solar Inverter: Any (from what I've been told). I'd go with micro inverters.
Controller Interface: Tesla App/cloud interface (no clue what it will be like at this point)
Pros:
Supports up to four powerwalls
Cons:
AC coupled powerwalls are slightly less efficient
You're relying on Teslas backup gateway into "tricking" grid-tied inverters into staying online when the grid is down.
Both the SolarEdge and the Tesla monitoring/control solutions will be cloud/app based. You *can* add a cellular modem to the SolarEdge inverter and the unit can be controlled from the inverter itself. I have no clue what the Tesla backup gateway will offer in terms of local control.
Thoughts anyone?
Note that I plan on installing two powerwalls. This is what makes the decision between these two configurations hard for me. If you need more than two powerwalls, it's an easy decision (go with AC coupled powerwalls).
DC Coupled:
Powerwall Type: DC (still available despite what some Tesla reps say)
Compatible Solar Inverter: SolarEdge StorEdge
Controller Interface: SolarEdge cloud interface. EX:
More efficient - DC batteries charged from DC solar
Auto-transfer switch allows for only critical items to be powered when the grid is down. See diagram in attached PDF
Less hardware overall (StorEdge inverter does everything)
One interface for everything
Cons:
The StorEdge inverter only supports two Powerwall 2 units. This is only a partial "con" though. Additional powerwall units *can* added but they'll require separate StoreEdge interfaces. If you have a
AC Coupled:
Powerwall Type: AC
Compatible Solar Inverter: Any (from what I've been told). I'd go with micro inverters.
Controller Interface: Tesla App/cloud interface (no clue what it will be like at this point)
Pros:
Supports up to four powerwalls
Cons:
AC coupled powerwalls are slightly less efficient
You're relying on Teslas backup gateway into "tricking" grid-tied inverters into staying online when the grid is down.
Both the SolarEdge and the Tesla monitoring/control solutions will be cloud/app based. You *can* add a cellular modem to the SolarEdge inverter and the unit can be controlled from the inverter itself. I have no clue what the Tesla backup gateway will offer in terms of local control.
Thoughts anyone?