Using a Generator along with PV + PW with Grid

[Oceanwolf]

Let me try to explain what I am trying to do. I have a cabin close to Yosemite that we are sheltering during the Covid. This area is pretty prone to PSPS and the last one was 3 days long. As long as I don't charge the car or don't use dryer or dishwasher, my load is around 500W-800Wh (I have an Emporia Energy system that I check each circuit breaker). I was using a Interlock Kit that only allows either the main or the generator circuit breaker can be on. My generator is a 3200Wh Inverter Type so it was OK during the PSPS. I was just shutting it down before going to bed.
Recently I had a 17 Panel Q-cell System (with individual inverters) installed and I removed my generator connect.
First question, if I install my Interlock Kit back in place, can I use my generator again? My concern is when the grid side is disconnected, solar will think I have power (from the generator) and come back online. As long as I can use all of the power I think the generator will just idle, if there is more power generated by solar, it will try to give it to the generator, is that a correct assumption? I don't want my generator to become a motor.
Second question, I am trying to get a Powerwall (2 PWs for Whole House coverage) to be able to use my power during the night too. In this case I will remove the generator. With snow etc, solar may not be enough to charge the PWs. Is there a way to use the generator to charge the PWs while the power is down? With the grid side circuit breaker off, what would happen if I use my generator, would the PW think power is back and start charging?

Thanks
Onur

 

[miimura]

Without Powerwalls, you should not run solar and generator at the same time. You should turn off the solar breakers at the same time you flip the interlock to run the generator.
With Powerwalls, you can use a generator with the new Gateway 2. However, I'm not sure about the details. I'm pretty sure you still can't charge the Powerwalls from the generator though. That was clearly a limitation with the original Tesla Backup Gateway. When you put in the order for the Powerwalls ask them to integrate the generator and ask about the limitations.

 

[Oceanwolf]

Without Powerwalls, you should not run solar and generator at the same time. You should turn off the solar breakers at the same time you flip the interlock to run the generator.
With Powerwalls, you can use a generator with the new Gateway 2. However, I'm not sure about the details. I'm pretty sure you still can't charge the Powerwalls from the generator though. That was clearly a limitation with the original Tesla Backup Gateway. When you put in the order for the Powerwalls ask them to integrate the generator and ask about the limitations.

I agree on the flipping the solar breakers off when using generator. I'll add a note to my panel.
I'll check the gateway 2 specs, good leads for me to search. Thank you

 

[Kodemonkey]

Let me try to explain what I am trying to do. I have a cabin close to Yosemite that we are sheltering during the Covid. This area is pretty prone to PSPS and the last one was 3 days long. As long as I don't charge the car or don't use dryer or dishwasher, my load is around 500W-800Wh (I have an Emporia Energy system that I check each circuit breaker). I was using a Interlock Kit that only allows either the main or the generator circuit breaker can be on. My generator is a 3200Wh Inverter Type so it was OK during the PSPS. I was just shutting it down before going to bed.
Recently I had a 17 Panel Q-cell System (with individual inverters) installed and I removed my generator connect.
First question, if I install my Interlock Kit back in place, can I use my generator again? My concern is when the grid side is disconnected, solar will think I have power (from the generator) and come back online. As long as I can use all of the power I think the generator will just idle, if there is more power generated by solar, it will try to give it to the generator, is that a correct assumption? I don't want my generator to become a motor.
Second question, I am trying to get a Powerwall (2 PWs for Whole House coverage) to be able to use my power during the night too. In this case I will remove the generator. With snow etc, solar may not be enough to charge the PWs. Is there a way to use the generator to charge the PWs while the power is down? With the grid side circuit breaker off, what would happen if I use my generator, would the PW think power is back and start charging?

Thanks
Onur

Without Powerwalls, you should not run solar and generator at the same time. You should turn off the solar breakers at the same time you flip the interlock to run the generator.
With Powerwalls, you can use a generator with the new Gateway 2. However, I'm not sure about the details. I'm pretty sure you still can't charge the Powerwalls from the generator though. That was clearly a limitation with the original Tesla Backup Gateway. When you put in the order for the Powerwalls ask them to integrate the generator and ask about the limitations.

Even if the solar breakers are flipped, aren't the powerwalls going to still vary the AC frequency to regulate the inverters (even though they are disconnected)? I would think having 60hz added into a 62hz power line might be an issue.

I have a buddy that tried to do this and Sunrun said it wasn't worth the problems it might cause. But that's just one guy...

 

[BrettS]

Even if the solar breakers are flipped, aren't the powerwalls going to still vary the AC frequency to regulate the inverters (even though they are disconnected)? I would think having 60hz added into a 62hz power line might be an issue.

I have a buddy that tried to do this and Sunrun said it wasn't worth the problems it might cause. But that's just one guy...

I think the OP had two questions... How could solar + generator work (to which the answer was “not well, turn off the inverters”) and could a generator charge the powerwalls (to which the answer was “no”). I don’t think the OP is planning to run a generator and powerwalls at the same time.

 

[shs1]

Here is a thread that I started some time ago when I wanted to install my PowerWall2 with a generator:

PowerWall 2 Interface with a Generator

BTW, I am also in the Yosemite area.

 

[Oceanwolf]

I think the OP had two questions... How could solar + generator work (to which the answer was “not well, turn off the inverters”) and could a generator charge the powerwalls (to which the answer was “no”). I don’t think the OP is planning to run a generator and powerwalls at the same time.

I think my first question was answered very clearly. I need to turn off the solar breakers in the main panel to be able to use the generator with the interlock.
The second question seems to be more complicated since a proper gateway can manage power from grid, solar, battery and generator. Of course if someone thought about to built one. If generac was smart they will built one otherwise their generators would be useless with solar and battery.

 

[Oceanwolf]

Here is a thread that I started some time ago when I wanted to install my PowerWall2 with a generator:

PowerWall 2 Interface with a Generator

BTW, I am also in the Yosemite area.

I am in Mi-Wuk Village

 

[Oceanwolf]

I am in Mi-Wuk Village

Here is a thread that I started some time ago when I wanted to install my PowerWall2 with a generator:

PowerWall 2 Interface with a Generator

I went through the first 7 pages, it seems like I have revitalized a 2 year old question no there is no answer yet out there.

 

[jjrandorin]

I believe the current answer is something along the lines of

"powerwalls can be setup with generators, but the generator will not charge the powerwall. It can be configured for the home to run on solar + powerwalls, then switch to generator if the powerwalls are empty, but other than that, there is no real interaction between the generator and powerwalls, if one is on grid."

I could be (very) wrong, but this is what I think is the current state of powerwalls working with generators (or not). It also does not seem to be a market tesla is worried about that much, frankly.

 

[shs1]

My installation is now complete with 2 Powerwalls and the generator and although the generator currently gets little use, it is great to know that it is there for extended outages with snow covered solar panels.

 

[jjrandorin]

My installation is now complete with 2 Powerwalls and the generator and although the generator currently gets little use, it is great to know that it is there for extended outages with snow covered solar panels.

Am I off base, above?

 

[Vines]

Am I off base, above?

You are on point, any other solution would be edgy and not Tesla compliant.

 

[h2ofun]

My installation is now complete with 2 Powerwalls and the generator and although the generator currently gets little use, it is great to know that it is there for extended outages with snow covered solar panels.

Then is my end game. Have the panels and generator already. PW's would be icing on the cake.

 

[shs1]

jjrandorin description is correct. I was reacting to the statement that seemed to imply that there was no progress in 2 years. As to skipping the Powerwalls, be aware that in a grid-tied system with no batteries, the solar does not work in a power failure as there is no voltage and frequency with which they can sync.