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Generator support

With how hot it is now, summer actually seems worst for my solar/storage energy use situation. I don't generate much more solar now vs. Winter due to summer gloom (cloudy till 9), but use tons more of power now.

During the sunny winter months, I'd generate like 40 kWh or so and use < 20kWh everyday (no need for AC). Now, I generate like 45 kWh or a bit more, but can use 40-50kWh if I decide to charge the EV that day.

I think if someone tried to live comfortably in all seasons, you cannot really rely on only solar/energy storage (batteries) due to multiple cloudy days or fires (in CA). Best off grid is still probably generator, big propane tank (for heat and maybe support the generator too if it takes propane) and more solar panels/batteries.

h2ofun runs his house at 70 I think when it's 95 outside. He uses 50kWh+ a day minimum :) so his batteries aren't going to last long.
I have the house set at 68 downstairs, and 70 upstairs. I use about 80 kwh per day, so yep, if no solar, batteries are gone real quick.
 
Wait, you are not connected to the utility grid at all?

If you are fully disconnected from the grid, then I do not understand why not follow Tesla off grid guidelines? Tesla has generator support for these homes, and the TEG can trigger the generator to start, recharge the batteries, and serve loads all at once.

Maybe I am missing something and you are just connected to a very bad grid?
Did I use the wrong words? I AM grid tied! Could never survive being off grid without a LOT more money investment, no thanks
 
Where can I find info on this?
Your Tesla Certified Installer for sure, I cannot share it as I am under NDA.

I think @BGbreeder might have posted a public link to the document?

Basically, you commission the system with the generator connected to the line side of the TEG, then send a control circuit over to the starting circuit of the generator.
 
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@cali8484 would using the Outback VFX3648 for AC->DC and 'buffering' the DC with a battery (the old Surrette 48V set) address any of the GTI complaints regarding the source DC?
What is the max GTI input power/current? If it's much lower than the max output power/current of your Outback then it may work.

Second as to recharging PW with 240 PSW inverter/generator, is that scenario manually controlling end-of-charge generator shut down?
Most likely unless you are willing to DIY some monitoring relay circuits.
 
Wait, you are not connected to the utility grid at all?
That is correct, and not for 22 years; never at this location.
Tesla has generator support for these homes, and the TEG can trigger the generator to start, recharge the batteries, and serve loads all at once.
Unfortunately the Honda EU7000is is not among their blessed generators and I have not yet found out thoroughly why, whether is is power quality issues, the fact that the stock unit is not auto-start, or whether it lacks built-in frequency syncing or the like.
 
What is the max GTI input power/current? If it's much lower than the max output power/current of your Outback then it may work.
1 SMA2000 and 1 SMA7.7; 9.7kw combined

cali8484 "Most likely unless you are willing to DIY some monitoring relay circuits."

No, just checking. Our generator/PW-Solar transfer switch is manual as well. Monitoring and manual control is not new for us. Also, it does not seem like that charging scenario would require settings changes.
 
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1 SMA2000 and 1 SMA7.7; 9.7kw combined

cali8484 "Most likely unless you are willing to DIY some monitoring relay circuits."

No, just checking. Our generator/PW-Solar transfer switch is manual as well. Monitoring and manual control is not new for us. Also, it does not seem like that charging scenario would require settings changes.

The SMA 7.7kW likely won't work at all but the SMA 2kW may work to some extent. It would be good if it can be configured for soft start. Also, you may need to pre-charge it to avoid in-rush current overloading and shutdown the DC supply.
 
What is the max GTI input power/current? If it's much lower than the max output power/current of your Outback then it may work.
I don't think I realized what you were asking with the initial question, and am not clear why a smaller than input GTI is needed. Does it have to do with the MPPT of the GTI?

The SMA 7.7kW likely won't work at all but the SMA 2kW may work to some extent. It would be good if it can be configured for soft start. Also, you may need to pre-charge it to avoid in-rush current overloading and shutdown the DC supply.
If the generator is set on eco mode, is that ~500 msec ramp-up sufficient duration. I am guessing that would depend on the actual DC supply being used.
In the case of the VFX Outback, I remember, judging from the rpms of the generator, a roughly 5 second ramp up time; I am guessing that soft-start is micro-processor controlled by the Outback.
 
Not sure if anyone has tried it but a more straight forward approach for black start (i.e. recharge a drained PW without the grid) would be to to use a large 240VAC pure sine wave off-grid inverter/generator (>7kW continuous for 1 PW) feeding the house via a transfer switch with the grid, GTI solar and all loads disconnected.
So in an off-grid situation, if someone puts separate manual transfer switches between their PWs and the AC combiner panel (to control whether an individual PW is connected to the AC combiner panel or to a generator), is the PWs communications with the Gateway via the Cat5 cable of concern. It seems one could not use the Tesla app to monitor the SOC of the PW being charged if it was disconnected. Or. If connected, would it screw with the monitoring if one PW is charging and the other(s) are discharging?
 
A Generator cannot sink any current, so having it exposed to the solar power at any time is a recipe for spectacular failure.
The solar and battery are always connected, so the generator cannot charge the battery even without solar.
So what's left is the Generator being able to feed the load circuits independent of all Solar/Battery/Smartness.?
Input A - Solar/Batteries/Grid
Input B - Generator
Output - Load circuits.
 
I don't think I realized what you were asking with the initial question, and am not clear why a smaller than input GTI is needed. Does it have to do with the MPPT of the GTI?
GTI, by design, will always try to pull its rated max power from the DC supply so your Outback (a DC voltage source) needs to be significantly bigger to avoid over-current shutdown.
 
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So in an off-grid situation, if someone puts separate manual transfer switches between their PWs and the AC combiner panel (to control whether an individual PW is connected to the AC combiner panel or to a generator), is the PWs communications with the Gateway via the Cat5 cable of concern. It seems one could not use the Tesla app to monitor the SOC of the PW being charged if it was disconnected. Or. If connected, would it screw with the monitoring if one PW is charging and the other(s) are discharging?
I don't see any inherent reason why the Gateway couldn't be connected assuming the grid and loads are disconnected. Of course the Tesla app may get confused. This is for a black start scenario so the goal is just to get the PW charged enough so it can start up on its own to charge from GTI? If I was doing it I would keep it simple and just start the generator and set a timer alarm for an hour to stop the generator.
 
A Generator cannot sink any current, so having it exposed to the solar power at any time is a recipe for spectacular failure.
The solar and battery are always connected, so the generator cannot charge the battery even without solar.
So what's left is the Generator being able to feed the load circuits independent of all Solar/Battery/Smartness.?
The scenarios being discussed above have the solar disconnected. I am comparing with the generator recommendations in the Tesla Powerwall Off-Grid System Design and Installation.
 
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This is for a black start scenario so the goal is just to get the PW charged enough so it can start up on its own to charge from GTI?
I did not realize you were only trying to bump-start it. Is this the purpose of the 'jumper battery'? (For those with a standby generator it would be the generator's starting battery. We have a 35AHr AGM battery kept near the Gateway to connect if needed.) I have a sense that you may be speaking of something else, as in a PW that has lost its reserve. I think the 'jumping' is for rebooting a gateway that has been without power for too long.

You had originally mentioned isolating one PW for direct charging. From my understanding, this is basically what the gateway does in the off-grid* standby generator auto-start designs, basically substituting generator input for grid input (*not to be confused with "going off grid" in grid-tied installations). Upstream solar gets disconnected.
 
I did not realize you were only trying to bump-start it. Is this the purpose of the 'jumper battery'? (For those with a standby generator it would be the generator's starting battery. We have a 35AHr AGM battery kept near the Gateway to connect if needed.) I have a sense that you may be speaking of something else, as in a PW that has lost its reserve. I think the 'jumping' is for rebooting a gateway that has been without power for too long.
Black start is for when PW has drained its reserve due to extended cloudy days during an outage. The Gateway backup battery is separate.

You had originally mentioned isolating one PW for direct charging. From my understanding, this is basically what the gateway does in the off-grid* standby generator auto-start designs, basically substituting generator input for grid input (*not to be confused with "going off grid" in grid-tied installations). Upstream solar gets disconnected.
It's a special case of the off-grid scenario where the PW(s) are drained and can't start up. The granularity of PW isolation depends on size of the generator. The grid is essentially powered by many large generators.
 

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