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Can Powerwall be charged from grid in backup-only mode?

h2ofun

Active Member
Aug 11, 2020
3,046
661
auburn, ca
I would suggest attempting to get PGE to send you something on their company letterhead stating that, "Yes, you can charge from the grid while connected to PGE and also setup with net metering solar".

If that is what they told you "yes" to, then they should be willing to send it to you in writing. if they do that (I doubt they will, but if they do), then you take that document and ask tesla to enable it for you.

Failing that, tesla isnt going to enable grid charging for you while you are connected to solar, regardless of what you got in an email.

Seems first thing you want is in writing something from the IRS
 

wjgjr

Active Member
May 11, 2020
1,331
1,051
Silver Spring, MD
Not sure why you would need that, if you got the powerwalls for basically "free" and would not be taking any tax credi (which is the situation @RKCRLR is in, and the one you hope to be in).
I agree - the IRS position seems pretty clear, and it is unlikely there would be much reason for them to take up the issue further or to get involved in general.

Tesla is the one that needs to be convinced. While we have speculated on the reasons Tesla makes this difficult (and I think it is some combination of concern for the IRS and for utilities, along with having an "easy" rule for the US) we know it is not a technical limitation but one of policy. In any event, the path that has worked in the past is what you suggested earlier, which is to get the utility (PGE in this case) to provide a letter saying it is okay, and likely also signing some statement from Tesla confirming you are not claiming the ITC.

I have said before that I think Tesla is going to need to change this policy, or at least streamline the process for changing the default behavior. Between the end of the residential ITC (though it may be extended), customers reaching the end of the ITC limits, and other incentives/use-cases for PWs, there are a number of reasons why increasing numbers of customers will want to charge from and/or discharge to the grid from PWs, even when they have solar, and Tesla should support that where allowed. But, for now, this is where we are, and unless Tesla did advertise or promise the functionality to individual customers, it seems like they are within their rights to implement this blanket policy.
 
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Merrill

Merrill
Jan 23, 2013
4,034
1,525
Sonoma, California
I agree - the IRS position seems pretty clear, and it is unlikely there would be much reason for them to take up the issue further or to get involved in general.

Tesla is the one that needs to be convinced. While we have speculated on the reasons Tesla makes this difficult (and I think it is some combination of concern for the IRS and for utilities, along with having an "easy" rule for the US) we know it is not a technical limitation but one of policy. In any event, the path that has worked in the past is what you suggested earlier, which is to get the utility (PGE in this case) to provide a letter saying it is okay, and likely also signing some statement from Tesla confirming you are not claiming the ITC.

I have said before that I think Tesla is going to need to change this policy, or at least streamline the process for changing the default behavior. Between the end of the residential ITC (though it may be extended), customers reaching the end of the ITC limits, and other incentives/use-cases for PWs, there are a number of reasons why increasing numbers of customers will want to charge from and/or discharge to the grid from PWs, even when they have solar, and Tesla should support that where allowed. But, for now, this is where we are, and unless Tesla did advertise or promise the functionality to individual customers, it seems like they are within their rights to implement this blanket policy.
Can someone explain what the ITC has to do with being able to charge your Powerwalls from the grid when in the winter there are days without enough solar to charge them.
 

getakey

Active Member
Jan 28, 2020
1,446
475
95762
you can charge your PWs in the winter as long as you set the reserve high. The Tax credit is based on Renewable energy sources.

Eligibility for residential properties
If you are installing energy storage on a residential property, it is eligible for a credit under the ITC – as long as the battery is only charged by an on-site renewable energy system like solar. If you don't have solar panels, and plan on charging the battery with electricity from the grid, it isn't eligible for the 26 percent solar tax credit.

Energy Storage Tax Credits Explained | EnergySage
 

Merrill

Merrill
Jan 23, 2013
4,034
1,525
Sonoma, California
you can charge your PWs in the winter as long as you set the reserve high. The Tax credit is based on Renewable energy sources.

Eligibility for residential properties
If you are installing energy storage on a residential property, it is eligible for a credit under the ITC – as long as the battery is only charged by an on-site renewable energy system like solar. If you don't have solar panels, and plan on charging the battery with electricity from the grid, it isn't eligible for the 26 percent solar tax credit.

Energy Storage Tax Credits Explained | EnergySage
Ok, so if you do not claim the ITC you can charge from the grid.
 

wjgjr

Active Member
May 11, 2020
1,331
1,051
Silver Spring, MD
Can someone explain what the ITC has to do with being able to charge your Powerwalls from the grid when in the winter there are days without enough solar to charge them.
The purpose of the ITC is to encourage moves to renewable energy. Batteries are only eligible if and when they are implemented as part of a renewable energy system. If they are used outside that system (which would likely include grid charging or any other charging from non-renewable sources,) then they are not eligible. (Additionally, the solution to having insufficient power to charge the batteries in the winter is to not discharge them so much, unless you are having regular power outages.)

There is nothing in the IRS rules that would prevent you from deciding that state incentives (like SGIP), price arbitrage, or added flexibility are a better option for you - if so, you simply don't claim the credit for the PWs (you can still claim it for the solar portion.) Then, you can use the PWs however you want, consistent with the rules with your utility and with the modes supported by Tesla. A lot of the conversation here revolves around the current reality that Tesla makes it very difficult to enable grid charging for US solar+PW customers.
 

Merrill

Merrill
Jan 23, 2013
4,034
1,525
Sonoma, California
The purpose of the ITC is to encourage moves to renewable energy. Batteries are only eligible if and when they are implemented as part of a renewable energy system. If they are used outside that system (which would likely include grid charging or any other charging from non-renewable sources,) then they are not eligible. (Additionally, the solution to having insufficient power to charge the batteries in the winter is to not discharge them so much, unless you are having regular power outages.)

There is nothing in the IRS rules that would prevent you from deciding that state incentives (like SGIP), price arbitrage, or added flexibility are a better option for you - if so, you simply don't claim the credit for the PWs (you can still claim it for the solar portion.) Then, you can use the PWs however you want, consistent with the rules with your utility and with the modes supported by Tesla. A lot of the conversation here revolves around the current reality that Tesla makes it very difficult to enable grid charging for US solar+PW customers.
Ok, I will not be claiming the ITC so if I need to in the winter I can charge the Powerwalls from the grid.
 

wjgjr

Active Member
May 11, 2020
1,331
1,051
Silver Spring, MD
Ok, I will not be claiming the ITC so if I need to in the winter I can charge the Powerwalls from the grid.
It is not that simple. All that means that if you do charge from the grid, the IRS would have no reason to come after you for tax fraud. But you still need to overcome the issues I note in the last paragraph - namely that you need to comply with the utility rules and the modes supported by Tesla. Right now, Tesla seems to make it very difficult to charge from the grid - there is no app or other user-facing setting that allows you to enable grid charging if you are a US customer with solar and PWs. And (as far as I am aware) the only success in changing this (as reported on this sub) involved getting a letter from the utility stating that grid charging did not violate their rules and also signing something from Tesla stating the customer would not claim the ITC. Unless something is changed, that is the likely process. For customers who have not yet ordered, it might be possible to raise this up-front with Tesla, though Tesla may just decline to proceed with the job.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Nov 28, 2018
10,840
12,568
Riverside Co. CA
Ok, so if you do not claim the ITC you can charge from the grid.

As has been mentioned many times, currently tesla does not allow this. Point your pitchfork at tesla. I am aware you dont like that answer, but that is the only answer we currently have. It is not a technical limitation, It is a limitation tesla imposes. You need to find a way to get tesla to let you do this which only one person reported here in the US has done so far.

Thats the direction you need to attempt to go in.
 

RKCRLR

Member
Apr 13, 2020
480
199
Garden Valley, CA
I don't think the ITC is a valid excuse for Tesla not allowing you to charge from the grid. If someone takes the ITC when they aren't eligible then the IRS will come after them, not Tesla. It isn't Tesla's responsibility to police it nor should it be.
I bet there are some solar installations out there that don't qualify for the ITC but Tesla installed them anyway.

The point of my post was Tesla told me that PG&E wouldn't allow charging from the grid but PG&E is denying that. If I were to pursue this further I'd ask Tesla to point out PG&E's policy that prevents charging from the grid when you have solar.

I think Tesla just doesn't want to deal with the complexity of allowing some people to charge from the grid but not others. And since most people take the ITC there probably wasn't much of a demand. But, as previously mentioned, this may be changing in the future. And, to be fair to Tesla, they never told me I would be able to to charge from the grid.

I wonder what the policy is with other battery systems.
 
Last edited:

wjgjr

Active Member
May 11, 2020
1,331
1,051
Silver Spring, MD
I don't think the ITC is a valid excuse for Tesla not allowing you to charge from the grid. If someone takes the ITC when they aren't eligible then the IRS will come after them, not Tesla. It isn't Tesla's responsibility to police it nor should it be.
I bet there are some solar installations out there that don't qualify for the ITC but Tesla installed them anyway.

The point of my post was Tesla told me that PG&E wouldn't allow charging from the grid but PG&E is denying that. If I were to pursue this further I'd ask Tesla to point out PG&E's police that prevents charging from the grid when you have solar.

I think Tesla just doesn't want to deal with the complexity of allowing some people to charge from the grid but not others. And since most people take the ITC there probably wasn't much of a demand. But, as previously mentioned, this may be changing in the future. And, to be fair to Tesla, they never told me I would be able to to charge from the grid.

I wonder what the policy is with other battery systems.
I agree that it is not Tesla's responsibility to police whether a customer is following the rules of the ITC. That said, I think there are probably a few reasons why they have chosen to be very careful. One is perception - they don't want to be associated with tax fraud, as it could hurt their image as well as potentially sour Congress on future incentives (noting that incentives have been an important part of Tesla's business model starting out both with cars and solar.) Having an easy way for customers to grid charge could be perceived as tacitly enabling fraud. And, particularly in the solar business, less reputable companies have tried to abuse the credits (including fake safe harbor scams which don't apply to residential, and over-billing or including non-qualifying costs.)

Related, I don't think Tesla wants to be involved in a hypothetical IRS audit. Should they have a way for customers to enable grid charging, the IRS would potentially ask (demand?) that Tesla turn over records of who was using that feature since, realistically, the IRS is unlikely to go after many individuals for possible violations of the charging rule. But, if they could uncover hundreds or thousands of possible cases through one central place, that might change.

And, there is still the hassle of utilities. Tesla needs to maintain good relationships to ensure there are not issues that hold up interconnects. While it sounds like PGE may not have a hard rule, some utilities do, and sometimes things are more complicated (such as the rules being dependent on the rate plan.) It would certainly help if there were standards all utilities had for documenting rules and rates as well as for managing things like PTO requests. But that does not yet seem to be the case, and it leads to things like Tesla having bad information on a utility's rules.

I kind of think the utilities are the biggest issue right now. Conceptually, where they can verify the utility allows it, I think the ITC could be handled with a one-page document giving the customer two options - "I am claiming the ITC for my PWs and understand that as a result, Tesla will lock my system from charging from the grid (except StormWatch) for the next five years" and "I swear that I will not claim the ITC for my PWs, and as a result, I will have the option to charge PWs from the grid, subject to the rules of my utility."
 

h2ofun

Active Member
Aug 11, 2020
3,046
661
auburn, ca
I agree that it is not Tesla's responsibility to police whether a customer is following the rules of the ITC. That said, I think there are probably a few reasons why they have chosen to be very careful. One is perception - they don't want to be associated with tax fraud, as it could hurt their image as well as potentially sour Congress on future incentives (noting that incentives have been an important part of Tesla's business model starting out both with cars and solar.) Having an easy way for customers to grid charge could be perceived as tacitly enabling fraud. And, particularly in the solar business, less reputable companies have tried to abuse the credits (including fake safe harbor scams which don't apply to residential, and over-billing or including non-qualifying costs.)

Related, I don't think Tesla wants to be involved in a hypothetical IRS audit. Should they have a way for customers to enable grid charging, the IRS would potentially ask (demand?) that Tesla turn over records of who was using that feature since, realistically, the IRS is unlikely to go after many individuals for possible violations of the charging rule. But, if they could uncover hundreds or thousands of possible cases through one central place, that might change.

And, there is still the hassle of utilities. Tesla needs to maintain good relationships to ensure there are not issues that hold up interconnects. While it sounds like PGE may not have a hard rule, some utilities do, and sometimes things are more complicated (such as the rules being dependent on the rate plan.) It would certainly help if there were standards all utilities had for documenting rules and rates as well as for managing things like PTO requests. But that does not yet seem to be the case, and it leads to things like Tesla having bad information on a utility's rules.

I kind of think the utilities are the biggest issue right now. Conceptually, where they can verify the utility allows it, I think the ITC could be handled with a one-page document giving the customer two options - "I am claiming the ITC for my PWs and understand that as a result, Tesla will lock my system from charging from the grid (except StormWatch) for the next five years" and "I swear that I will not claim the ITC for my PWs, and as a result, I will have the option to charge PWs from the grid, subject to the rules of my utility."

To me this focus of some with charging from the grid just is dumb. To pay the cost for batteries to play the game of getting energy cheaper, or sending it back to the grid when it is more expensive, would just end up with PGE no allowing at all. Bottom line is they need to make a profit or they are out of business.

I like the comment that during the winter when many cannot fully charge their batteries, they should not be using unless a power outage.

Some folks trying to game the system ends up hurting everyone. This is what is happening with SGIP money now. Folks tried to get free batteries for second homes, they were not 100% well, when they made lots of money. Because of this, they were forced to totally change the program and these folks are complaining.
 

Merrill

Merrill
Jan 23, 2013
4,034
1,525
Sonoma, California
For me, I wouldn't even care if I was allowed to charge from the grid if PG&E could provide reliable service.
Yes, I agree and with warmer winters and possible PSPS you might get your power shut off. If your batteries are not fully charged then what, I know you will say keep them on high reserve. I think this whole thing about not being able to charge from the grid is ridiculous.
 

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