Questions about Solar+Powerwall3+Two Model Ys

[GateFather]

Signed up yesterday to have a somewhat large 24.3kW system with 4 Powerwalls installed at my home which looks like this with 60 panels overall. The front of the house faces Northwest and back of the house is Southeast.

This system is in southern NJ and AC Electric is the Electric service provider. Here are some questions I was hoping to get some input on:

1. Inverter Ratio: The team told me the Powerwalls would be Powerwall 3. I've read and understand they have a built in Inverter that has 20kW DC to 11.5kW AC or a DC to AC Ratio of about 1.74 which seems high from what I've read. Is this right?
   
   
2. Solar Clipping?: If the DC Solar max is 20kW and my system is 23.4kW (60 panels at 405w each), wouldn't I see clipping of the additional 3.4kW if the system can get to max at any point in the day? I did read that the max rating of the panels is in a lab and not normally the true output, with 400w panels generally generating more like 305-310w in the real world. Is this true? If so, I guess this is fine since max solar DC output would be 18.6kW and PW2 can handle 20kW.
   
   
3. MPPT/String Config: It looks like the powerwall 3 spec shows 6 x MPPTs which means they can zone the system into 6 separate sections for max efficiency, even with the configuration being split only across 2 sides of the roof. I'd assume that I should request this since there are times in the early morning and late afternoon where there is shade on various corners of the roof. With the design they sent above, I assume they will do 2 strings by default, but should I ask for 3 sections on each side so 6 in total?
   
   
4. Placement: In the google satalite photo, the electrical panel is actually on the side of the house you can see, opposite from the driveway, towards the front of the house. The main panel sits in the basement around the same place. Based on the below system design, would they have to put the 4x Powerwall 3 on that side of the house? When ordering I chose "Let Tesla Decide" because I didn't want to pay $1800 to have them in the garage, even though I'd prefer them to be there. Is this a big deal?
   
   
   
   
   
   
5. Is anyone familiar with AC Electric in NJ and any "Gotchas" I should look out for. I've heard things like the Electric company can set a max of 120% of electric generation (which, believe it or not, 24.3kW is 97% of my 12 month avg generation) but also things like not allowing the PWs to be charged from grid. I've heard some have exceptions to this where they allow it only through storm based functionality like Tesla's Storm watch.

Sorry for the long one, but appreciate any help!

 

[GregBallantyne]

I can't speak to all of your questions, but can perhaps provide a little perspective on some of them.....

The small difference between inverter capacity in my system (2kw) has yet to result in any identifiable generation reduction due to clipping. The angles of my house roof have some similarity in deviation from ideal with yours, so my experience so far would lead me to conclude that it's likely to be a non issue. I have observed momentary bursts of production higher than my inverter capacity, but only right around the summer solstice and, incidentally, momentarily higher than my rated production capacity. 99.9999% of operation occurs at levels lower than either.

With regard to PowerWall location, my thoughts are that in NJ (probably similar to MD) an Inside a controlled temperature space location would be preferable to an outside location. Battery temperature affects useable capacity, and it's in the warmest and coldest seasons that you will be seeing the value of having more battery capacity which (at least in my case) can lead to thinking about adding more. Mine are in the basement, close to the load center inside and the inverters/gateway outside. Mine are also PW2, so I'm not familiar with how PW3 may differ for these considerations, but temperature effects on battery chemistry won't be different.

 

[Vines]

Signed up yesterday to have a somewhat large 24.3kW system with 4 Powerwalls installed at my home which looks like this with 60 panels overall. The front of the house faces Northwest and back of the house is Southeast.

View attachment 1032836 View attachment 1032837

This system is in southern NJ and AC Electric is the Electric service provider. Here are some questions I was hoping to get some input on:

1. Inverter Ratio: The team told me the Powerwalls would be Powerwall 3. I've read and understand they have a built in Inverter that has 20kW DC to 11.5kW AC or a DC to AC Ratio of about 1.74 which seems high from what I've read. Is this right?

No, you have calculated the ratio for a single Powerwall 3. It looks like you are quoted 4 of them. Each of them likely will have a portion of the solar connected to them, unless there is some interconnection restriction with your utility.

1. 
   
   
2. Solar Clipping?: If the DC Solar max is 20kW and my system is 23.4kW (60 panels at 405w each), wouldn't I see clipping of the additional 3.4kW if the system can get to max at any point in the day? I did read that the max rating of the panels is in a lab and not normally the true output, with 400w panels generally generating more like 305-310w in the real world. Is this true? If so, I guess this is fine since max solar DC output would be 18.6kW and PW2 can handle 20kW.

See above, there will not likely be clipping because the PV will be split across multiple inverters.

1. 
   
   
2. MPPT/String Config: It looks like the powerwall 3 spec shows 6 x MPPTs which means they can zone the system into 6 separate sections for max efficiency, even with the configuration being split only across 2 sides of the roof. I'd assume that I should request this since there are times in the early morning and late afternoon where there is shade on various corners of the roof. With the design they sent above, I assume they will do 2 strings by default, but should I ask for 3 sections on each side so 6 in total?

You don't want to analyze over this unless you really understanding stringing. Longer strings are almost always better, as then when shade hits a few panels and those bypass diodes activate, the remaining modules in the string will still have enough voltage to hit the MPPT voltage window. Also the higher the voltage, the higher the voltage drop and line losses. For instance the Vdrop at 60 VDC (inverter startup floor) of a string of modules with 100' one way distance and 13A current is almost 8%.
That same string with 480 VDC (max MPPT voltage) would have a 1% voltage drop. Power loss has a similar relationship, so you give up quite a bit to make short strings. Not to mention the wasted copper wire in pulling all 6 strings back, with each one at minimum string length.

1. 
   
   
2. Placement: In the google satalite photo, the electrical panel is actually on the side of the house you can see, opposite from the driveway, towards the front of the house. The main panel sits in the basement around the same place. Based on the below system design, would they have to put the 4x Powerwall 3 on that side of the house? When ordering I chose "Let Tesla Decide" because I didn't want to pay $1800 to have them in the garage, even though I'd prefer them to be there. Is this a big deal?
   
   View attachment 1032845
   
   

I am surprised that $1800 would push you out of the better garage location, that seems like a small price to pay to have the equipment where it makes most sense. I know with Powerwall+ and PW2 they would derate once the battery got cold. I see there is no warning of derating with the PW3 so maybe this isn't such a big deal anymore to put them inside in cold climates.

1. Is anyone familiar with AC Electric in NJ and any "Gotchas" I should look out for. I've heard things like the Electric company can set a max of 120% of electric generation (which, believe it or not, 24.3kW is 97% of my 12 month avg generation) but also things like not allowing the PWs to be charged from grid. I've heard some have exceptions to this where they allow it only through storm based functionality like Tesla's Storm watch.

Sorry for the long one, but appreciate any help!

 

[GateFather]

I can't speak to all of your questions, but can perhaps provide a little perspective on some of them.....

The small difference between inverter capacity in my system (2kw) has yet to result in any identifiable generation reduction due to clipping. The angles of my house roof have some similarity in deviation from ideal with yours, so my experience so far would lead me to conclude that it's likely to be a non issue. I have observed momentary bursts of production higher than my inverter capacity, but only right around the summer solstice and, incidentally, momentarily higher than my rated production capacity. 99.9999% of operation occurs at levels lower than either.

With regard to PowerWall location, my thoughts are that in NJ (probably similar to MD) an Inside a controlled temperature space location would be preferable to an outside location. Battery temperature affects useable capacity, and it's in the warmest and coldest seasons that you will be seeing the value of having more battery capacity which (at least in my case) can lead to thinking about adding more. Mine are in the basement, close to the load center inside and the inverters/gateway outside. Mine are also PW2, so I'm not familiar with how PW3 may differ for these considerations, but temperature effects on battery chemistry won't be different.

Appreciate your insight here. I did not even consider the temperature effect on the battery, which is strange since I've owned a model 3 for 5 years and currently own 2 Model Ys. Of course it would be better to have the PWs somewhere temperature controlled!

No, you have calculated the ratio for a single Powerwall 3. It looks like you are quoted 4 of them. Each of them likely will have a portion of the solar connected to them, unless there is some interconnection restriction with your utility.


See above, there will not likely be clipping because the PV will be split across multiple inverters.

You don't want to analyze over this unless you really understanding stringing. Longer strings are almost always better, as then when shade hits a few panels and those bypass diodes activate, the remaining modules in the string will still have enough voltage to hit the MPPT voltage window. Also the higher the voltage, the higher the voltage drop and line losses. For instance the Vdrop at 60 VDC (inverter startup floor) of a string of modules with 100' one way distance and 13A current is almost 8%.
That same string with 480 VDC (max MPPT voltage) would have a 1% voltage drop. Power loss has a similar relationship, so you give up quite a bit to make short strings. Not to mention the wasted copper wire in pulling all 6 strings back, with each one at minimum string length.


I am surprised that $1800 would push you out of the better garage location, that seems like a small price to pay to have the equipment where it makes most sense. I know with Powerwall+ and PW2 they would derate once the battery got cold. I see there is no warning of derating with the PW3 so maybe this isn't such a big deal anymore to put them inside in cold climates.

Appreciate your feedback as well. I read that for multiple PW3 configurations, only one of them will have the built in inverter and a second "type" of PW3 is being built to only have the battery storage internals. Not sure how true this is, definitely something I will be asking my advisor during my first meeting with him tomorrow. It seems strange that we'd pay the same price for PW3s if only one has components worth thousands more than the others. I would hope at least 2 would have inverters both for failover and total DC to AC handling capabilities.

As far as location, I guess you're right. In the grand scheme of things, it was $1800 to put them in the garage, whereas it was $8300 to have them put them in the basement. Part of my thinking was that my panel is in the basement, so perhaps it will actually be easiest for them to put them there anyways. If so, I would be saving $8300 and getting the benefits of them being in a fully temperature controlled space. The downside there is that the panel also happens to be in my wife's office within our finished basement. Not sure shes going to want to be sitting next to 4 PW3s all day, everyday. Not to mention....do they put off heat and would it cause a heating issue for that room? I guess I will know more once the site inspection happens next Thursday, but I will ask my advisor these questions tomorrow regardless.

 

[miimura]

Assuming the PW3 "expansion battery" is actually available, I would think that two PW3 and each having an expansion battery would be appropriate for your situation.

 

[GateFather]

Assuming the PW3 "expansion battery" is actually available, I would think that two PW3 and each having an expansion battery would be appropriate for your situation.

I have a meeting with my solar consultant at 1pm today. Here are the questions I plan to ask. The 4x Powerwall 3 is still a mystery to me. If there are

• Can you confirm my system will have Powerwall 3 (sales rep I spoke to at time of order said they would be Powerwall 3 and even sent me links to documentation on them.
• Why is the down payment incentive only $16,038 if there is a $770 SREC trade in per kW of the system and my system is spec’d at 24.3? Should be $18711.
• Will all 4 Powerwalls be full Powerwall 3s with the inverter?
• Is there an “expansion model” that does not include the non-battery tech?” If not all with inverter tech, shouldn’t the “battery only” or “expansion” units cost less? If not, I would want all units with the non-battery tech for future upgrade potential if new panels come out down the road with more efficiency/higher wattage.
• My electrical meter is on the opposite side of my house from garage, with the panel in a finished basement office – where do you think the 4x Powerwall 3s will go?
• What is the Powerwall 3’s inverter DC to AC Ratio? Assuming 1.739 since DC is 20kW and AC is 11.5kW. This seems pretty high. Will there be an issue with my utility or local municipality due to this?
• Even though my design is setup as 2 sets of panels, one on each roofline, will installers make use of all 6 MPPT/String Configurations to split the panels into 6 strings for maximum efficiency while various parts of the panels might be shaded due to things like cloud cover?
• Are there any common Local Issues you’re aware of?
• Can the Powerwalls 3s be filled from the grid at my location even when there is not a storm?
• When available, I would like a list of all the equipment with specs and details on each thing.

Do any of these not make sense to ask? Anything else that would be good to cover for a first call?

 

[Matt-FL]

Just a note, when the PWs are charging, there is fan noise. At least there is with the PW2s. That may be annoying for someone working nearby.

 

[Vines]

Assuming the PW3 "expansion battery" is actually available, I would think that two PW3 and each having an expansion battery would be appropriate for your situation.

So far I know almost nothing about the expansion batteries, except that they aren't released to the 3rd party installers at this time.

 

[GateFather]

Just a note, when the PWs are charging, there is fan noise. At least there is with the PW2s. That may be annoying for someone working nearby.

I've been watching the "Tesla Installer Academy" videos on Powerwall 3 this morning just to learn more about how the install goes etc. and this was one of the things they brought up. Fans pull air to run cool air from the bottom of the unit up and over the front and back of the equipment inside. Each has 2 fans they said is about as loud as a refrigerator on average but can be louder or softer depending on ambient speed. I also read some things from a year ago or so that said they won't even install Powerwall 3s in finished basements.

Another thing I thought was interesting is that the Powerwall 3s connect via a 60amp breaker. Wouldn't this create a bottleneck for power supply to the home panel before the 4x combined output is reached?

If it truly is 60amp, then there is a possibility they could most easily put the Powerwall 3s in my garage as it sits just above the 100amp sub panel in my unfinished utility space in my basement and is subsequently where both garage wall connectors are wired into.

 

[GateFather]

So far I know almost nothing about the expansion batteries, except that they aren't released to the 3rd party installers at this time.

So in your opinion this means a 4x Powerwall 3 system would come with 4 Powerwall 3s each with their own inverter available?

 

[Vines]

So in your opinion this means a 4x Powerwall 3 system would come with 4 Powerwall 3s each with their own inverter available?

Right now, this is what I understand can be installed now. If installing multiple PW3, each gets their own 60A breaker, and each gets a split of the PV system connected to it. We are fully onboarded with PW3 now and have started selling and installing this solution.

If another installer has access to something that I don't there may be other options I do not know about. There are improvements coming later this year so once those arrive I cannot say what the best design is.

For instance many utilities would look at those 2 systems very differently though they had similar energy capacity, this would be one of many things to consider when making a final choice.

As @miimura pointed out one reasonable future design would be (2) units with DC strings connected and (2) expansion units with (2) 60A breakers interconnected

 

[GateFather]

Right now, this is what I understand can be installed now. If installing multiple PW3, each gets their own 60A breaker, and each gets a split of the PV system connected to it. We are fully onboarded with PW3 now and have started selling and installing this solution.

If another installer has access to something that I don't there may be other options I do not know about. There are improvements coming later this year so once those arrive I cannot say what the best design is.

For instance many utilities would look at those 2 systems very differently though they had similar energy capacity, this would be one of many things to consider when making a final choice.

As @miimura pointed out one reasonable future design would be (2) units with DC strings connected and (2) expansion units with (2) 60A breakers interconnected

Would the 2 units with DC Strings connected you're referring to be the "full" Powerwall 3 as they are today and then the 2 that are just expansion units would be battery units? If so, I would agree this would be ideal. Not sure there is really a need for 4 entire PW3 units, but I would like the extra battery storage for backup.

I mocked up my home when it was built, so I went in and just added how I think this system could look. See images below. However, now that you're saying each of the PW3 as they are today would have its own 60amp breaker, I'm thinking this may not actually work. The sub panel is only a 100AMP service total. However, even my main panel is only 200AMP - so I don't think its realistic to even connect 4 PW to it.

 

[Vines]

Would the 2 units with DC Strings connected you're referring to be the "full" Powerwall 3 as they are today and then the 2 that are just expansion units would be battery units? If so, I would agree this would be ideal. Not sure there is really a need for 4 entire PW3 units, but I would like the extra battery storage for backup.

I mocked up my home when it was built, so I went in and just added how I think this system could look. See images below. However, now that you're saying each of the PW3 as they are today would have its own 60amp breaker, I'm thinking this may not actually work. The sub panel is only a 100AMP service total. However, even my main panel is only 200AMP - so I don't think its realistic to even connect 4 PW to it.

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View attachment 1033307

The Powerwall is a PCS capable device so it can be programmed to limit it's backfeed to a given panel, as soon as the future metering hardware options support that.

I haven't heard of full vs partial powerwall 3 yet but this makes sense to not include the inverter if there is no need for AC power.

 

[GateFather]

Just ended my call with my Tesla Project Advisor and got some good insight on a few things that folks here may find useful.

• Why is down payment incentive only $16038 if there is a $770 STRC trade in per kW of the system and my system is spec’d at 24.3? Should be $18711.
  
  • 0.66 cents per watt. Website is not accurate – these change all the time.

• Will all 4 Powerwalls be Powerwall 3? Is there an “expansion model” that does not have the non-battery tech or will they all have inverters etc?” If not all with inverter tech, shouldn’t the “battery only” or “expansion” units cost less? If not, I would want all units with the non-battery tech.
  
  • Two would be Powerwall 3 for sure, potentially all 4. If not needed for 3rd and 4th Powerwall, then it could be a storage only solution, but this would only be if utility does not allow extra inverters included in system, even if they will be turned off.
  • Storage only solution, right now, is to add Powerwall 2s. There is no price difference if this is necessary. I told him I would not want this as I feel I would be paying for something I am not receiving. Extra, unused inverters could serve to quickly get my system back up in the case that one of the other unit's inverters go bad and parts are backordered/not readily available. Redundancy in available inverters means my system should be able to be back up quickly if one in use goes down.
  • It is possible to fully decommission the inverter inside of a Powerwall 3. Ideal for my build will be 4 Powerwall 3s where 2 have the inverters dormant or 1 dormant and a third derated.
  • My project will likely be to go with 4 Powerwall 3s. Some permitting authorities (utilities) don’t allow total inverter output to exceed a guideline they have. They will count that for each Powerwall 3 with an inverter inside of it, even if Tesla tells them some won't be used.
  • AC Electric (my provider) – He did not see a cap listed for them in his database, so it is likely my project will have 4 Powerwall 3s.

• My meter is on the opposite side of my house from the garage. The main panel in basement in finished office – where do you think Powerwall 3s will go?
  
  • Need to wait for the in-person assessment for actual answer.
  • Likely will put the Powerwall 3s outdoors next to the meter.
  • Powerwall 3s are outdoor rated and weatherproof. ~85%-90% of Powerwall installs are outdoor next to meter.

• What is the Powerwall 3’s inverter DC to AC Ratio?
  
  • More focused Panels to Powerwall DC to AC Ratio. Panels are 24.3kW (DC). Inverters are the AC amount. Could be, for example, that 2 of the inverters are fully working while a third is derated to achieve desired ratio.
  • They will never make it more than 1.4, but shoot for 1.3 in most cases. They can derate inverters. In my case, they will likely have 4 Powerwall 3s which will give full flexibility to get the number to 1.3.

• Even though my design is setup as 2 sets of panels, one on each roofline, will installers make use of the 6 MPPT/String Configurations to split the panels into 6 strings for maximum efficiency while various parts of the panels can be shaded due to things like cloud cover?
  
  • They will design in the most efficient way based on shade models for my specific project.

• Can the Powerwall 3's be Stack mounted or other configurations?
  
  • Can be either. Lots of options available. This will be part of final design, but I can provide input at that point. Usually design chosen is best aesthetic design within bounds of what is allowed for my home/area.

• Can the Powerwall 3s be filled from the grid at my location even when there is not a storm?
  
  • Need to ask Utility this question.
  • Most utilities allow for at least storm watch mode, but not filling Powerwall 3 from Grid normally.

 

[Koolio46]

Looks like you got all of your questions answered, but thought I'd share what I recently went through (installation was 3 weeks ago).

Got a 13.77kW panel system with 1 Powerwall 3. My DC:AC ration is 1.20 (using the 11.5kW AC inverter in the PW3). If I read my full site plan spec sheet correctly, it shows the PW3 inverter can be set to 3 capacities: 11.5, 7.6, and I thin it was 5.xx. So, it sounds like that's what they'll do is mix and match these across your PWs to get the right ratio.

As for strings, that's what they did with my setup. I have 4 strings with a 1a / 1b and a 2a / 2b (jumpered).

 

[IronCoffee_Max]

I just got a 19.035 kW panel system with two PowerWall 3s installed mid February. Here is what I see in my docs:

Nameplate Rating: 19.035 kW DC
Inverter Nameplate Rating: 23 kW AC
AC Rating: 17.244 kW CEC-AC
Estimated Annual Production: 25779 kWh
Total Nameplate Energy Capacity: 27.00 kWh

I'd be happy to share any other info if you'd like

 

[Matt-FL]

Just to add here, keep track of what your designer creates vs what your installers will want to install. In my instance, I had provided shading details to the designer and he created multiple stings to accommodate on paper. However, the installers changed the design to match what was easier for them to deploy. What the installers said to me at install seemed to make sense, but now that I have more knowledge, I see what it was about. Work to keep what your design lays out, and ask hard questions if the installers say different.

 

[GateFather]

I just got a 19.035 kW panel system with two PowerWall 3s installed mid February. Here is what I see in my docs:

Nameplate Rating: 19.035 kW DC
Inverter Nameplate Rating: 23 kW AC
AC Rating: 17.244 kW CEC-AC
Estimated Annual Production: 25779 kWh
Total Nameplate Energy Capacity: 27.00 kWh

I'd be happy to share any other info if you'd like

Appreciate the offer! So I am assuming if you're AC rating is 17.244, then both of your PW3 inverters are being used but degraded to achieve a lower DC to AC ratio. Looks like you have a 1.1 ratio, is that right? How has it been going since the system is commissioned? Are you keeping the PW3s fully charged and sending more excess power to the grid during the day or are you depleting or partially depleting PW3 during night and using solar to mainly fill them + home energy needs during they day. I've read if you don't have time of day surge pricing, then it makes more sense to leave PW3 at 100% (even at night) and just use excess daytime energy to send back to grid for utility credits. I'm thinking this might be my situation, although I originally thought I would power the house at night from batteries to be more independent of the grid. Economically, it may not make sense for me.

Just to add here, keep track of what your designer creates vs what your installers will want to install. In my instance, I had provided shading details to the designer and he created multiple stings to accommodate on paper. However, the installers changed the design to match what was easier for them to deploy. What the installers said to me at install seemed to make sense, but now that I have more knowledge, I see what it was about. Work to keep what your design lays out, and ask hard questions if the installers say different.

Interesting, couldn't you simply demand they use the designer plans that you approved rather than make a last minute change which you then have no time to run by advisors of yours. This is what I would say. I'm assuming they lessened the amount of strings at install so that they didn't have to run multiple conduit down to the PW3s in your case. This would really be the only reason I could see not to keep the original design with what I'm assuming had more strings than were ultimately installed for you. I've read of this happening somewhat frequently. Installers don't want to run more conduit since all the cables cannot fit in one, so at install time try to get the homeowner to agree to less strings for aesthetic purposes, usually siting minimal differences in overall functionality. In my case, there are clearly different times of day where different sections of my panels will have or will not have shade, so it will be very important that the MPPT/string config is done well to maximize efficiency. My project advisor assured me this will be taken into account this Thursday during the in-person assessment that I have scheduled.

 

[IronCoffee_Max]

Appreciate the offer! So I am assuming if you're AC rating is 17.244, then both of your PW3 inverters are being used but degraded to achieve a lower DC to AC ratio. Looks like you have a 1.1 ratio, is that right?

I suppose so. So far I've seen no clipping.

How has it been going since the system is commissioned? Are you keeping the PW3s fully charged and sending more excess power to the grid during the day or are you depleting or partially depleting PW3 during night and using solar to mainly fill them + home energy needs during they day. I've read if you don't have time of day surge pricing, then it makes more sense to leave PW3 at 100% (even at night) and just use excess daytime energy to send back to grid for utility credits. I'm thinking this might be my situation, although I originally thought I would power the house at night from batteries to be more independent of the grid. Economically, it may not make sense for me.

Going great. I was using the option to use my PW3s fully to cover any usage until depleted because I was self-sufficient/off-grid almost completely, but I didn't like the idea of my PW cycling so much. Also Solar would spend half the day refilling the powerwalls every day. I do have a partial time of use (my $ / kWh doesn't change, but they add a demand charge from 4-8pm), so I now have it set to just cover 4-8. With net-metering, I end up negative every day. So I like that better.

 

[GateFather]

I suppose so. So far I've seen no clipping.


Going great. I was using the option to use my PW3s fully to cover any usage until depleted because I was self-sufficient/off-grid almost completely, but I didn't like the idea of my PW cycling so much. Also Solar would spend half the day refilling the powerwalls every day. I do have a partial time of use (my $ / kWh doesn't change, but they add a demand charge from 4-8pm), so I now have it set to just cover 4-8. With net-metering, I end up negative every day. So I like that better.

View attachment 1034374

Awesome. I’d do the same if it had partial time of use. I think that’s the best use for the power walls since you avoid the demand charge and still get enough net metering to end of negative. My pricing is fixed all the time so I think the outcome with be the same whether I use and cycle the powerwalls or keep them charged and send excess back to the grid. For this reason I was really considering whether I should keep them but I like the thought of being able to flip a switch and go off grid for some period of time if I need it or if an outage forces it. Moved here in 2020 and we had one outage the first winter, and spent 2021 Christmas without power. No outages since, though.