How to change gateway to never export?

[h2ofun]

So, if the power goes down, the gateway knows to never try to send power back to the grid. If the batteries are full, it shuts down the inverter.

So, can we get the fw changed in the gateway so it NEVER can feed back power to the grid. Then we can go back and tell PGE we have no solar capable to send to grid
so no 8 bucks per month per kw charge?

 

[zƬesla]

So, can we get the fw changed in the gateway so it NEVER can feed back power to the grid. Then we can go back and tell PGE we have no solar capable to send to grid

Go off grid?

 

[wwhitney]

The $8/kw proposed charge would not apply to existing NEM1 and NEM2 customers, so the question is moot from that point of view. And I don't know if there's a "non-export" exception to the proposed $8/kw charge in "NEM3".

But sure, you can configure the Powerwall for non-export. Does Self-consumption mode do that already? I guess it won't curtail solar to avoid exporting.

There's a setting in the configuration menu to monitor a set of CTs and impose a limit on the current seen. As long as your install has a set of CTs on the feeder to the grid, you can tell the PW never to let that current go negative (current towards the grid). I haven't confirmed that the GW will actually curtail solar as required if the PWs are full, but presumably that's the idea.

With your segmented install with 2 GWs, this would have the inefficient consequence that if one GW has excess solar and the PWs are full, but the other GW is a net consumer, the first GW will still curtail production.

Cheers, Wayne

 

[h2ofun]

Go off grid?

No, not to go off grid. To just function like it did before I had any solar or batteries.

 

[h2ofun]

The $8/kw proposed charge would not apply to existing NEM1 and NEM2 customers, so the question is moot from that point of view. And I don't know if there's a "non-export" exception to the proposed $8/kw charge in "NEM3".

But sure, you can configure the Powerwall for non-export. Does Self-consumption mode do that already? I guess it won't curtail solar to avoid exporting.

There's a setting in the configuration menu to monitor a set of CTs and impose a limit on the current seen. As long as your install has a set of CTs on the feeder to the grid, you can tell the PW never to let that current go negative (current towards the grid). I haven't confirmed that the GW will actually curtail solar as required if the PWs are full, but presumably that's the idea.

With your segmented install with 2 GWs, this would have the inefficient consequence that if one GW has excess solar and the PWs are full, but the other GW is a net consumer, the first GW will still curtail production.

Cheers, Wayne

I still am not convinced we know the final answer to the $8/kw when, or what the export cost will be, when.

I just am brainstorming options depending on what happens. If I can save 3000 a year in contect costs, it does not matter what I might lose compared to the old way of what NEM2 and TOU used to be.

Again, since the GW stops exporting if grid down, tesla could change the fw to, it seems, make it such that the solar could never export, just like the powerwalls cannot export in the US either without special programs. So, it is all just in the fw control

 

[holeydonut]

Since you're under NEM2, you have 14 years of not paying the per month grid-access fee. This is assuming you don't add that floatilla of solar panels I keep wanting you to build on the lake. And I guess this assumes NEM 4.0 doesn't show up in 5 years and screws all this up. While I agree this is a super-crappy situation for the long term ownership of your property, you should expect tech innovation in the next few years to help address your problem in 2035.

But if you really don't want PG&E to get your energy, just open your disconnect levers heh. I thought your whole house could run off your 5x Powerwalls?

 

[h2ofun]

Since you're under NEM2, you have 14 years of not paying the per month grid-access fee. This is assuming you don't add that floatilla of solar panels I keep wanting you to build on the lake. And I guess this assumes NEM 4.0 doesn't show up in 5 years and screws all this up. While I agree this is a super-crappy situation for the long term ownership of your property, you should expect tech innovation in the next few years to help address your problem in 2035.

But if you really don't want PG&E to get your energy, just open your disconnect levers heh. I thought your whole house could run off your 5x Powerwalls?

I will 100% believe it when something is officially passed. There is the monthly fee, and the export credit amount. I just think it is too early
to assume NEM2 folks for 15 years are going to see no changes, but I hope I am wrong.

Powerwalls only work, legally, if the solar can charge them! And since most have gas heat, they have no idea what I am dealing with being 99% electric!!!!!!!!!!!!!!!!!!!!!!!!!!!! So, for 8 to 9 months of the year, yep I can charge the batteries and export more to the grid than I use. But for the other 3 months, when I run my heat pumps for heat, I am pulling lots from the grid. I have no choice, even with the crazy amount of solar, which a lot is north facing so does not do anything this time of the year.

 

[holeydonut]

I will 100% believe it when something is officially passed. There is the monthly fee, and the export credit amount. I just think it is too early
to assume NEM2 folks for 15 years are going to see no changes, but I hope I am wrong.

Powerwalls only work, legally, if the solar can charge them! And since most have gas heat, they have no idea what I am dealing with being 99% electric!!!!!!!!!!!!!!!!!!!!!!!!!!!! So, for 8 to 9 months of the year, yep I can charge the batteries and export more to the grid than I use. But for the other 3 months, when I run my heat pumps for heat, I am pulling lots from the grid. I have no choice, even with the crazy amount of solar, which a lot is north facing so does not do anything this time of the year.

I'm curious, if you open your grid disconnect ... and then have a gas generator or wind turbine feeding your generation panel ... and put a solar CT on this inflow of suds...

What does the the Tesla system do? Does the Gateway "think" it's getting solar power and charge the batteries? Or does it just screw everything up since the voltage may not be the necessary 242+ you see from true solar production?

 

[h2ofun]

Switch the main breaker off. The gateway will think the grid is down

BUT this does not solve the issue that PGE has my with 30K PTO. This is what I would have to consider getting rid of, has nothing to do with the grid connection

 

[jjrandorin]

You started off asking a question on how to configure for no solar export. if you want to do that, you can likely call tesla and ask them to configure that for you on your system. Thats the answer to that question, although I dont think that will change a thing for you regarding these proposed charges. The rest of the discussion should be in the other thread I stickied, since its about the CPUC roll out.

 

[Vines]

You started off asking a question on how to configure for no solar export. if you want to do that, you can likely call tesla and ask them to configure that for you on your system. Thats the answer to that question, although I dont think that will change a thing for you regarding these proposed charges. The rest of the discussion should be in the other thread I stickied, since its about the CPUC roll out.

Without explicit control over the inverter, the Gateway cannot control the inverter to setup non-export mode. The powerwall+ can do this because the inverter is under the same control as the Gateway. With a 3rd party inverter the only control over production is to frequency shift, which is not possible while on grid.

So no, you cannot go into export-only mode unless you have a PW+, this may be possible if you have a Tesla inverter, but I do not know that to be sure.

 

[miimura]

SolarEdge has the ability to do zero export, but you have to use their Grid CT consumption measurement system to implement it. Tesla has installed SolarEdge inverters in the past but don't install the SE consumption measurement system.

 

[wwhitney]

Without explicit control over the inverter, the Gateway cannot control the inverter to setup non-export mode. . . . With a 3rd party inverter the only control over production is to frequency shift, which is not possible while on grid.

Good point. Although the GW could be configured to go off-grid when the PWs are full and solar exceeds the load to implement non-export. Presumably not currently implemented? That strategy would have some limitations, for it to be seamless you'd need enough inverter power to run all the house loads.

The powerwall+ can do this because the inverter is under the same control as the Gateway

I'm not sure if that statement is based on your knowledge of the product, or just a comment that it theoretically could, if Tesla has implemented the proper GW to PV inverter communications.

Cheers, Wayne

 

[h2ofun]

You started off asking a question on how to configure for no solar export. if you want to do that, you can likely call tesla and ask them to configure that for you on your system. Thats the answer to that question, although I dont think that will change a thing for you regarding these proposed charges. The rest of the discussion should be in the other thread I stickied, since its about the CPUC roll out.

I would be shocked if tesla did that. And if they will not, what are other options?

 

[Vines]

Good point. Although the GW could be configured to go off-grid when the PWs are full and solar exceeds the load to implement non-export. Presumably not currently implemented? That strategy would have some limitations, for it to be seamless you'd need enough inverter power to run all the house loads.

It would be possible if you go off-grid as you outlined, but you may have some power fluctuations as the contactors open and close. Also this would wear the contactors somewhat.

I'm not sure if that statement is based on your knowledge of the product, or just a comment that it theoretically could, if Tesla has implemented the proper GW to PV inverter communications.

What I am trying to say is that the GW control portion is located within the PW+ inverter and this is why the PW+ Inverter can curtail the PV Inverter output just enough to feed the loads. I do not know if the other discrete Tesla inverters could be wired to somehow enable this communication. I don't install either so I don't have first-hand experience.

 

[skepticcyclist]

BUT this does not solve the issue that PGE has my with 30K PTO. This is what I would have to consider getting rid of, has nothing to do with the grid connection

I don't know what to tell you. Unless you can find a way to split your system with a subpanel and have only a couple of light loads use the grid while everything else is completely off grid on a separate panel with your solar and battery

 

[holeydonut]

I don't know what to tell you. Unless you can find a way to split your system with a subpanel and have only a couple of light loads use the grid while everything else is completely off grid on a separate panel with your solar and battery

Does Roseville have any good lakefront properties? I think moving may be his easiest solution...

 

[wwhitney]

this is why the PW+ Inverter can curtail the PV Inverter output just enough to feed the loads.

I was trying to ask if you know that the PW+ currently _can_ curtail the PV Inverter, or was just observing that the feature is feasible?

Although I guess with the "run before PTO" option Tesla is promoting, it has to be running in non-export mode, so it must be able to curtail the PV inverter. That would mean only the PW+ installations offer the "run before PTO" option, is that correct?

Cheers, Wayne

 

[holeydonut]

It would be possible if you go off-grid as you outlined, but you may have some power fluctuations as the contactors open and close. Also this would wear the contactors somewhat.

What I am trying to say is that the GW control portion is located within the PW+ inverter and this is why the PW+ Inverter can curtail the PV Inverter output just enough to feed the loads. I do not know if the other discrete Tesla inverters could be wired to somehow enable this communication. I don't install either so I don't have first-hand experience.

Are you all planning to get Powerwall+ for your customers? Or are you restricted to putting in regular PW2s as AC coupled with non-Tesla solar inverters per the current reseller agreement?

 

[Vines]

I was trying to ask if you know that the PW+ currently _can_ curtail the PV Inverter, or was just observing that the feature is feasible?

Although I guess with the "run before PTO" option Tesla is promoting, it has to be running in non-export mode, so it must be able to curtail the PV inverter. That would mean only the PW+ installations offer the "run before PTO" option, is that correct?

Cheers, Wayne

I have seen that it is possible from here on the forums since you can run a PW+ system before PTO and the production graphs look crazy with massive clipping as the inverter tries to clamp down power that cannot be used by the home or battery right now.

I believe that only the PW+ installs have this option, but then again we don't install them so my knowledge is all second-hand. It seems reasonable if only Tesla inverters are onsite that the PW+ may be able to control these other inverters in the future. As pointed out, Solar Edge inverters can also do this. Likely in the future inverters will be judged with features like this in mind. Only the better ones could be used in some of these grid-limited circumstances, with some level of export control.

Are you all planning to get Powerwall+ for your customers? Or are you restricted to putting in regular PW2s as AC coupled with non-Tesla solar inverters per the current reseller agreement?

PW+ is a nice product for sure, but so far we are sticking to the GW2 with Sunpower AC-PV panels. We do not tend to adopt the newest latest greatest immediately, except in certain circumstances when the benefit and the reliability is clear.

The backup switch is the real game-changer, to eliminate many service upgrades. Without that, even if we were to use PW+ we will still need the GW2. We often install 3 or more PW, and the PW+ the battery portion can only be stacked 2 deep, so that's a limitation as well. Customers almost always get PTO within 30 days and usually like a week from the final inspection.

No way we are leaving any customers in limbo with the backup switch process with PGE being confusing without clear rules. This risks screwing up the whole project and then triggers a service upgrade most likely.