over-production with PGE

[jjrandorin]

hi, no I don't believe that I said it excluded time-shifting; if I did somewhere then I was wrong. The true measures of a rechargable battery are retention over time and total energy throughput, with the latter usually more important. Total energy throughput refers to how many times you can cycle the battery. My 7.8 year calculation assumed 100% energy retention. If you can manage cycling a battery twice a day instead of once, your warranty will be voided in half of the time. I don't believe any battery has an unlimited # cycles unless DepthOfDischarge is limited to small percentages such as 10%. That's fantasy. So for a time-shifting application (charge offpeak, discharge onpeak) where the battery is cycled nearly 100% once per day, it might first encounter the aggregate throughput limitation, depending on the battery. If I were looking for any reason to void someone's warranty performance claim, I would look first to the net accumulated aggregate throughput. Here is the link: https://www.tesla.com/sites/default/files/pdfs/powerwall/Powerwall_2_AC_Warranty_USA_1-1.pdf

View attachment 772127

View attachment 772130

My point is, the warranty is for "70% capacity at 10 years, unlimited cycles, when used in solar self consumption (time shifting) or backup only mode. thats the only point I am making. That is what tesla is warrantying. When used with solar, there is no "37MWh limit" for warranty considerations.

You stated:

@jjrandorin I looked at the PowerWall2 warranty. What you say is true, but only for backup purposes where # of cycles is small (thus unlimited).

And my reply is "Thats incorrect, the warranty is not only for backup purposes, where the # of cycles is small, but for unlimited cycles, at 70% capacity, for 10 years, if charged from solar / PV, and there is no fine print that says otherwise for tesla powerwalls.

 

[wwu123]

And my use case would be cycling it every day (time shifting), not for infrequent events such as wildfire outage backups.

I may be misunderstanding your goal, but if you are a massive net generator for the year, there is not a big point to time-shifting. Peak rates vs non-peak rates don't matter - you just accrue a larger sum that you don't actually get paid out. Since at true-up, you instead get a measly 2-3 cents per kwh, regardless of what you accrued.

I think the only benefit of time-shifting on NEM2, when being a net generator, is to avoid NBC's, which I think are on the order of 3c /kwh.

 

[HariSeldon]

No battery manufacturer will give you unlimited cycles, despite how you interpret it. That is the reason for total aggregate energy throughput spec. Look at any competing battery and see if they offer unlimited cycles. Pure fantasy. Backup mode means infrequent utilization (cycles) to plow through not-too-long-outages. When you look at the big picture for daily time-shifting, you have a planned "grid outage" every day, when you discharge the battery. That is not infrequent. I'm a retired EE and know a bit about battery cells and chemistries, but certainly no expert. Expected cycles for batteries are typically <5000, depending on the chemistry. 5000 cycles is <14 years. That might mean unlimited to some people. PW2 37 Mwatt-hrs is <8 years assuming 100% DOD daily. I interpret Tesla's "self consumption/backup only" to mean self consumption only in backup mode. If the cycle count were unlimited, then why is there an alternate spec for total aggregate energy throughput? Don't get me wrong: I'm not saying the battery will drop dead after the energy aggregate spec has been exceeded. But if it does die, you won't have a successful warranty claim if that spec was exceeded.

If you still don't believe me, read on.............

Here is a review of the warranty for a popular alternate battery: We Read LG's Battery Warranty so You Don't Have To | EnergySage
It refers to a throughput "clause".

Here is an excerpt of the RESU1XH warranty from the LG Chem website Product Info｜LG Home Battery Note that it says "at the earlier of". In my opinion, Tesla's warranty is misleading, as I don't believe they have any magic over the competition (maybe marketing?). Well, I hope that this info helps. If we continue to disagree, I'm ok with that. And thanks again for your previous replies.

 

[HariSeldon]

I may be misunderstanding your goal, but if you are a massive net generator for the year, there is not a big point to time-shifting. Peak rates vs non-peak rates don't matter - you just accrue a larger sum that you don't actually get paid out. Since at true-up, you instead get a measly 2-3 cents per kwh, regardless of what you accrued.

I think the only benefit of time-shifting on NEM2, when being a net generator, is to avoid NBC's, which I think are on the order of 3c /kwh.

Hi @wwu123,

my goal was to understand whether I made a huge mistake of installing solar recently, coupled later with some family members deciding to live elsewhere, and realizing then that I would have a relatively huge net surplus of energy at true-up time (and being paranoid about PGE). As I was reading the PGE NEM2 spec, in Special Conditions section 5 on NetSurplusCompensation, I became concerned that I might violate something for producing way more energy than I consumed. Without doing anything, I'll have 1000-4000 kWh surplus with only a 5kW installation. But responses here so far indicate that there is no consequence for me, only that the utility will happily sell my excess energy at market rates but only reimburse me about $0.04/kWh for it. I knew that before I dived in, but I didn't plan for the reduced occupancy. I was of the belief that the utility didn't want my unused excess energy. And no, I'm not interested in a battery. But thanks for the response!

 

[RKCRLR]

No battery manufacturer will give you unlimited cycles, despite how you interpret it. That is the reason for total aggregate energy throughput spec. Look at any competing battery and see if they offer unlimited cycles. Pure fantasy. Backup mode means infrequent utilization (cycles) to plow through not-too-long-outages. When you look at the big picture for daily time-shifting, you have a planned "grid outage" every day, when you discharge the battery. That is not infrequent. I'm a retired EE and know a bit about battery cells and chemistries, but certainly no expert. Expected cycles for batteries are typically <5000, depending on the chemistry. 5000 cycles is <14 years. That might mean unlimited to some people. PW2 37 Mwatt-hrs is <8 years assuming 100% DOD daily. I interpret Tesla's "self consumption/backup only" to mean self consumption only in backup mode. If the cycle count were unlimited, then why is there an alternate spec for total aggregate energy throughput? Don't get me wrong: I'm not saying the battery will drop dead after the energy aggregate spec has been exceeded. But if it does die, you won't have a successful warranty claim if that spec was exceeded.

If you still don't believe me, read on.............

Here is a review of the warranty for a popular alternate battery: We Read LG's Battery Warranty so You Don't Have To | EnergySage
It refers to a throughput "clause".

Here is an excerpt of the RESU1XH warranty from the LG Chem website Product Info｜LG Home Battery Note that it says "at the earlier of". In my opinion, Tesla's warranty is misleading, as I don't believe they have any magic over the competition (maybe marketing?). Well, I hope that this info helps. If we continue to disagree, I'm ok with that. And thanks again for your previous replies.

View attachment 772358

hi, no I don't believe that I said it excluded time-shifting; if I did somewhere then I was wrong. The true measures of a rechargable battery are retention over time and total energy throughput, with the latter usually more important. Total energy throughput refers to how many times you can cycle the battery. My 7.8 year calculation assumed 100% energy retention. If you can manage cycling a battery twice a day instead of once, your warranty will be voided in half of the time. I don't believe any battery has an unlimited # cycles unless DepthOfDischarge is limited to small percentages such as 10%. That's fantasy. So for a time-shifting application (charge offpeak, discharge onpeak) where the battery is cycled nearly 100% once per day, it might first encounter the aggregate throughput limitation, depending on the battery. If I were looking for any reason to void someone's warranty performance claim, I would look first to the net accumulated aggregate throughput. Here is the link: https://www.tesla.com/sites/default/files/pdfs/powerwall/Powerwall_2_AC_Warranty_USA_1-1.pdf

View attachment 772127

View attachment 772130

I've read the Powerwall warranty several times and the only interpretation of the table above that makes sense is that there is no throughput limit (with regards to warranty) when the Powerwalls are being used in a self consumption and/or backup mode. While the battery may not actually last and need to be replaced if fully discharged every day it would still be covered under warranty the way that is worded. You could contact Tesla for clarification if it you still have concerns.

Additionally, I thought I read somewhere in the SGIP documentation that in order for a ESS to qualify for residential SGIP (which Powerwalls do) it has to have a minimum 10 year warranty, but I'm not sure of this.

 

[Redhill_qik]

Hi @wwu123,

my goal was to understand whether I made a huge mistake of installing solar recently, coupled later with some family members deciding to live elsewhere, and realizing then that I would have a relatively huge net surplus of energy at true-up time (and being paranoid about PGE). As I was reading the PGE NEM2 spec, in Special Conditions section 5 on NetSurplusCompensation, I became concerned that I might violate something for producing way more energy than I consumed. Without doing anything, I'll have 1000-4000 kWh surplus with only a 5kW installation. But responses here so far indicate that there is no consequence for me, only that the utility will happily sell my excess energy at market rates but only reimburse me about $0.04/kWh for it. I knew that before I dived in, but I didn't plan for the reduced occupancy. I was of the belief that the utility didn't want my unused excess energy. And no, I'm not interested in a battery. But thanks for the response!

Since you will be a net generator, a couple of suggestions. First, check to see if your area is covered by a Community Choice Aggregator (CCA) as they usually have higher compensation rates than the PG&E wholesale NSC rate. Second, consider switching from gas appliances to electric to lower your gas bill.

 

[HariSeldon]

I've read the Powerwall warranty several times and the only interpretation of the table above that makes sense is that there is no throughput limit (with regards to warranty) when the Powerwalls are being used in a self consumption and/or backup mode. While the battery may not actually last and need to be replaced if fully discharged every day it would still be covered under warranty the way that is worded. You could contact Tesla for clarification if it you still have concerns.

Additionally, I thought I read somewhere in the SGIP documentation that in order for a ESS to qualify for residential SGIP (which Powerwalls do) it has to have a minimum 10 year warranty, but I'm not sure of this.

I too have read it several times and wonder how many people read it incorrectly. It is unfortunate. Context is everything. Most people never read their warranties. Anyone doing an ROI should. I agree that the PW table makes you think there is no throughput limit, but why don't you check the warranties of competing batteries? I did some time ago when I first got interested in solar. You will find, sometimes in the fineprint unfortunately, that there always is a clause that supercedes the primary spec. And thus the Tesla warranty should be read in the same context. Unless Tesla knows something about batteries that nobody else does, in which case there would be little or no competition. Not realistic. That clause refers to the total aggregate energy processed by the battery. Every erg of energy processed degrades the battery. And if you fully cycle your battery every day, you could potentially lower the warranty time to less than 10 years. I think PWs are good batteries, but don't think there is anything special about them. And I surely wouldn't purchase one based on purported unlimited cycling, unless it is qualified by an well defined infrequent use case such as backup. Backup mode is relevant to infrequent unplanned outages, and thus the number of cycles is virtually unlimited. All other modes are frequent such as daily "planned outages" during peak hours, for example. Please read the EnergySage review of the RESU1XH warranty. Please read the RESU1XH actual warranty or just my excerpts of it in my earlier post (links provided there too). Do you still believe that the PW offers something that every other competitor does not? BTW I'm no more of a fan of the RESU1XH battery than a PW. Both batteries are on the same playing field so to speak. The PW 37 Mwatt-hrs is a competitive spec. But you could find yourself in a <10 year exception clause.

I should comment on the semantics of using a slash in a phrase. THAT/THIS could mean THIS or THAT. But it can also mean THIS further qualifies THAT, which is an AND. For example black/white means black or white, I think that's clear. But self-consumption/backup could be interpreted either way, and it shouldn't be misinterpreted. It should be interpreted in the context of competing batteries and their warranties. Notice that the RESU1XH warranty says "self-consumption or backup" without a slash and is much clearer than the Tesla table. The RESU1XH table more clearly illustrates the energy aggregate throughput spec that supercedes the 10 year spec, confirmed by the warranty wording in section 4 Performance Warranty. The relevant words are "at the earlier of". I believe that warranty arbitration of a PW would confirm that there is no such thing as unlimited cycling in any self-consumption mode, except backup mode only. I'm NOT a lawyer.

Ask yourself, if you still believe that Tesla means self-consumption or backup, why is there a total aggregate energy throughput spec provided in the warranty? It's just the basic limitation of the chemistry/physics, not to be circumvented by anyone. Notice I used a slash here. Chemistry really means physics. There are different physics for each chemistry. Is there anything beyond self-consumption or backup mode? LG Chem doesn't think so, for residential useage. I think the PWs we are referring to here are for resideniail usage also. I think anyone thinking about getting a PW and relying on unlimited cycling inside of 10 years should take your advice and get clarification from Tesla, or somehow research prior warranty claims and their outcomes. My battery choice, if I ever get one, shall foremost have a competitive total energy aggregate throughput spec under daily cycling, that gives me a reasonable ROI, followed by reputation, cost, etc. Otherwise, for backup mode applications, that spec goes to the bottom of the list.

 

[Vines]

OP it sounds like your question is answered. I'll go along with the OT discussion.

Despite the rest of the industry and whatever is spoken about them, the Tesla warranty is pretty clear. As long as you are charging them from PV then they have a 10 year unlimited cycle warranty.

Of course, practically it would be difficult to use more than 40 MWh of renewable energy over 10 years, when used sensibly and within the intended purpose. Even if you could squeeze the full 13 kWh out of the ESS every single day for 10 years you would only total 47.5 mWh in 5 years, and that assumes nearly no capacity loss, which is impossible.

I wonder if the Powerwall will ever get a longer warranty, imagine a 25 year warranty!

 

[Redhill_qik]

I too have read it several times and wonder how many people read it incorrectly. It is unfortunate. Context is everything. Most people never read their warranties. Anyone doing an ROI should. I agree that the PW table makes you think there is no throughput limit, but why don't you check the warranties of competing batteries? I did some time ago when I first got interested in solar. You will find, sometimes in the fineprint unfortunately, that there always is a clause that supercedes the primary spec. And thus the Tesla warranty should be read in the same context. Unless Tesla knows something about batteries that nobody else does, in which case there would be little or no competition. Not realistic. That clause refers to the total aggregate energy processed by the battery. Every erg of energy processed degrades the battery. And if you fully cycle your battery every day, you could potentially lower the warranty time to less than 10 years.

I should comment on the semantics of using a slash in a phrase. THAT/THIS could mean THIS or THAT. But it can also mean THIS further qualifies THAT, which is an AND. For example black/white means black or white, I think that's clear. But self-consumption/backup could be interpreted either way, and it shouldn't be misinterpreted. It should be interpreted in the context of competing batteries and their warranties. Notice that the RESU1XH warranty says "self-consumption or backup" without a slash and is much clearer than the Tesla table. The RESU1XH table more clearly illustrates the energy aggregate throughput spec that supercedes the 10 year spec, confirmed by the warranty wording in section 4 Performance Warranty. The relevant words are "at the earlier of". I believe that warranty arbitration of a PW would confirm that there is no such thing as unlimited cycling in any self-consumption mode, except backup mode only. I'm NOT a lawyer.

Ask yourself, if you still believe that Tesla means self-consumption or backup, why is there a total aggregate energy throughput spec provided in the warranty? It's just the basic limitation of the chemistry/physics, not to be circumvented by anyone. Notice I used a slash here. Chemistry really means physics. There are different physics for each chemistry. Is there anything beyond self-consumption or backup mode? LG Chem doesn't think so, for residential useage. I think the PWs we are referring to here are for resideniail usage also. I think anyone thinking about getting a PW and relying on unlimited cycling inside of 10 years should take your advice and get clarification from Tesla, or somehow research prior warranty claims and their outcomes. My battery choice, if I ever get one, shall foremost have a competitive total energy aggregate throughput spec under daily cycling, that gives me a reasonable ROI, followed by reputation, cost, etc. Otherwise, for backup mode applications, that spec goes to the bottom of the list.

Warranties are contracts and as such in most states only the content in the document matters. What any other company decides to write in their warranties would not be relevant.

For some reason you are not reading footnote 2, which states "Storing solar energy generated by an onsite array, and using that stored energy (i) for daily self-consumption and/or (ii) for use as backup power." This footnote is included in both the Powerwall 2 warranty and the newer Powerwall+ warranty. In the Powerwall 2 warranty the "Unlimited cycles" is also bolded. So the slash is explicitly is explicitly defined as both "and" and "or".

Why are there two specs being called out? IMHO it is because the Powerwalls might be used in situations that might generate sustained maximum charge/discharge rates that would stress the battery far more than would happen under solar self-consumption with a gradual ramp of the charge rate in the morning as the PV array starts generating and a discharge rate that rarely gets to 5kW.

 

[Vines]

I too have read it several times and wonder how many people read it incorrectly. It is unfortunate. Context is everything. Most people never read their warranties. Anyone doing an ROI should. I agree that the PW table makes you think there is no throughput limit, but why don't you check the warranties of competing batteries? I did some time ago when I first got interested in solar. You will find, sometimes in the fineprint unfortunately, that there always is a clause that supercedes the primary spec. And thus the Tesla warranty should be read in the same context. Unless Tesla knows something about batteries that nobody else does, in which case there would be little or no competition. Not realistic. That clause refers to the total aggregate energy processed by the battery.

Warranties are contracts and as such in most states only the content in the document matters. What any other company decides to write in their warranties would not be relevant.

For some reason you are not reading footnote 2, which states "Storing solar energy generated by an onsite array, and using that stored energy (i) for daily self-consumption and/or (ii) for use as backup power." This footnote is included in both the Powerwall 2 warranty and the newer Powerwall+ warranty. In the Powerwall 2 warranty the "Unlimited cycles" is also bolded. So the slash is explicitly is explicitly defined as both "and" and "or".

Why are there two specs being called out? IMHO it is because the Powerwalls might be used in situations that might generate sustained maximum charge/discharge rates that would stress the battery far more than would happen under solar self-consumption with a gradual ramp of the charge rate in the morning as the PV array starts generating and a discharge rate that rarely gets to 5kW.

Thanks @Redhill_qik you took the words out of my mouth.

 

[RKCRLR]

I too have read it several times and wonder how many people read it incorrectly. It is unfortunate. Context is everything. Most people never read their warranties. Anyone doing an ROI should. I agree that the PW table makes you think there is no throughput limit, but why don't you check the warranties of competing batteries? I did some time ago when I first got interested in solar. You will find, sometimes in the fineprint unfortunately, that there always is a clause that supercedes the primary spec. And thus the Tesla warranty should be read in the same context. Unless Tesla knows something about batteries that nobody else does, in which case there would be little or no competition. Not realistic. That clause refers to the total aggregate energy processed by the battery. Every erg of energy processed degrades the battery. And if you fully cycle your battery every day, you could potentially lower the warranty time to less than 10 years. I think PWs are good batteries, but don't think there is anything special about them. And I surely wouldn't purchase one based on purported unlimited cycling, unless it is qualified by an well defined infrequent use case such as backup. Backup mode is relevant to infrequent unplanned outages, and thus the number of cycles is virtually unlimited. All other modes are frequent such as daily "planned outages" during peak hours, for example. Please read the EnergySage review of the RESU1XH warranty. Please read the RESU1XH actual warranty or just my excerpts of it in my earlier post (links provided there too). Do you still believe that the PW offers something that every other competitor does not? BTW I'm no more of a fan of the RESU1XH battery than a PW. Both batteries are on the same playing field so to speak. The PW 37 Mwatt-hrs is a competitive spec. But you could find yourself in a <10 year exception clause.

I should comment on the semantics of using a slash in a phrase. THAT/THIS could mean THIS or THAT. But it can also mean THIS further qualifies THAT, which is an AND. For example black/white means black or white, I think that's clear. But self-consumption/backup could be interpreted either way, and it shouldn't be misinterpreted. It should be interpreted in the context of competing batteries and their warranties. Notice that the RESU1XH warranty says "self-consumption or backup" without a slash and is much clearer than the Tesla table. The RESU1XH table more clearly illustrates the energy aggregate throughput spec that supercedes the 10 year spec, confirmed by the warranty wording in section 4 Performance Warranty. The relevant words are "at the earlier of". I believe that warranty arbitration of a PW would confirm that there is no such thing as unlimited cycling in any self-consumption mode, except backup mode only. I'm NOT a lawyer.

Ask yourself, if you still believe that Tesla means self-consumption or backup, why is there a total aggregate energy throughput spec provided in the warranty? It's just the basic limitation of the chemistry/physics, not to be circumvented by anyone. Notice I used a slash here. Chemistry really means physics. There are different physics for each chemistry. Is there anything beyond self-consumption or backup mode? LG Chem doesn't think so, for residential useage. I think the PWs we are referring to here are for resideniail usage also. I think anyone thinking about getting a PW and relying on unlimited cycling inside of 10 years should take your advice and get clarification from Tesla, or somehow research prior warranty claims and their outcomes. My battery choice, if I ever get one, shall foremost have a competitive total energy aggregate throughput spec under daily cycling, that gives me a reasonable ROI, followed by reputation, cost, etc. Otherwise, for backup mode applications, that spec goes to the bottom of the list.

If you search the SGIP handbook for "warranty" you will find multiple places that state equipment must have a 10 year minimum warranty:

https://www.cpuc.ca.gov/-/media/cpuc-website/divisions/energy-division/documents/self-generation-incentive-program/2021-sgip-handbook-v4.pdf

So if the ESS systems don't have a 10 year minimum warranty then they wouldn't be eligible for SGIP incentives.

 

[HariSeldon]

OP it sounds like your question is answered. I'll go along with the OT discussion.

Despite the rest of the industry and whatever is spoken about them, the Tesla warranty is pretty clear. As long as you are charging them from PV then they have a 10 year unlimited cycle warranty.

Of course, practically it would be difficult to use more than 40 MWh of renewable energy over 10 years, when used sensibly and within the intended purpose. Even if you could squeeze the full 13 kWh out of the ESS every single day for 10 years you would only total 47.5 mWh in 5 years, and that assumes nearly no capacity loss, which is impossible.

I wonder if the Powerwall will ever get a longer warranty, imagine a 25 year warranty!

It would be useful for you to provide more detail with your calculations. The PW spec indicates 13 useful kWh. And that goes down to 70% per the warranty. So let's assume that the average energy pulled out of the battery is 0.5*(13 + 0.7*13)=11kWh. Daily cycling of average 11 kWh is 37000/11 = 3363 cycles = 9.2 < 10 years. Or even fewer cycles because the 70% actually turns out to be 80% (8.7 years) at failure, which is more likely. Does that fall outside sensible use from PV? So you are saying that Tesla will abide by the warranty for that last year or two, even if the aggregate was exceeded? Clearly, LG Chem and others won't, they explicitly state so. And why do their batteries meet the SGIP handbook minimum 10 year warranty, but still have the aggregate exclusion clause? Kindly explain that please.

I can imagine too, LOL on the 25 year warranty! I'll be glad to give you a 20 year warranty for twice the price tomorrow, and reinvest half of your money for my purposes, some of it to cover your future warranty claim at a much likely lower replacement cost.

I'll get back to perusing the NEM3 thread rant for now. I wonder how far Governor Newsom will let the CPUC go?

 

[HariSeldon]

Since you will be a net generator, a couple of suggestions. First, check to see if your area is covered by a Community Choice Aggregator (CCA) as they usually have higher compensation rates than the PG&E wholesale NSC rate. Second, consider switching from gas appliances to electric to lower your gas bill.

great suggestions, thank you. I will definitely look into a CCA. And switching from gas to electric has been on my mind recently. Probably will do that when we remodel.

 

[Redhill_qik]

So you are saying that Tesla will abide by the warranty for that last year or two, even if the aggregate was exceeded? Clearly, LG Chem and others won't, they explicitly state so. And why do their batteries meet the SGIP handbook minimum 10 year warranty, but still have the aggregate exclusion clause? Kindly explain that please.

Tesla created the warranty for their products and will be held accountable to the terms that they created that form the contract with the customer. So, yes they will abide by the terms. What LG Chem does in their warranty is not relevant.

Why? Tesla likely wanted to provide more assurance to customers that were concerned about cycling to be able to sell more product. Tesla has a lot of experience with battery cycling and they can model the expected charge/discharge rates for residential use with a solar charge rate that will be less than the max 5kW most of the time and house load discharge rates that will be less than the max 5kW most of the time along with expected actual daily discharge amounts. They ran the numbers and have concluded that any warranty claims will be acceptable.

I have two Powerwalls and I use them to get through the five Peak hours from 4:00-9:00pm. The max that was discharged was 19.70kWh and the average was 6.45 kWh, so for each unit that is 9.85 kWh max and 3.23 kWh average. So, I will very likely be well under the 37.8 MWh limit after 10 years as I expect most units will be.

The right question to be asking is if participating in the Tesla Virtual Power Plant program moves you from the standard solar charge/discharge category into the "other application" category.

 

[Vines]

It would be useful for you to provide more detail with your calculations. The PW spec indicates 13 useful kWh. And that goes down to 70% per the warranty. So let's assume that the average energy pulled out of the battery is 0.5*(13 + 0.7*13)=11kWh. Daily cycling of average 11 kWh is 37000/11 = 3363 cycles = 9.2 < 10 years. Or even fewer cycles because the 70% actually turns out to be 80% (8.7 years) at failure, which is more likely. Does that fall outside sensible use from PV? So you are saying that Tesla will abide by the warranty for that last year or two, even if the aggregate was exceeded? Clearly, LG Chem and others won't, they explicitly state so. And why do their batteries meet the SGIP handbook minimum 10 year warranty, but still have the aggregate exclusion clause? Kindly explain that please.

I can imagine too, LOL on the 25 year warranty! I'll be glad to give you a 20 year warranty for twice the price tomorrow, and reinvest half of your money for my purposes, some of it to cover your future warranty claim at a much likely lower replacement cost.

I'll get back to perusing the NEM3 thread rant for now. I wonder how far Governor Newsom will let the CPUC go?

I know imagine that effect on the industry when everyone is giving limited 10 year warranties if Tesla gave out a massively longer one?

I think Tesla would abide by the warranty and if you had 69% capacity after 9.2 years you would get a remanufactured battery with better but not perfect capacity. I am not their warranty department obviously, but so far the few RMA we put through have been fulfilled pretty quickly.

Meanwhile LG chem (Now LG Energy) are recalling a couple thousand home batteries due to the magic smoke coming out. I don't think both these companies have the same grade of product.

 

[yblaser]

I know imagine that effect on the industry when everyone is giving limited 10 year warranties if Tesla gave out a massively longer one?

I think Tesla would abide by the warranty and if you had 69% capacity after 9.2 years you would get a remanufactured battery with better but not perfect capacity. I am not their warranty department obviously, but so far the few RMA we put through have been fulfilled pretty quickly.

Meanwhile LG chem (Now LG Energy) are recalling a couple thousand home batteries due to the magic smoke coming out. I don't think both these companies have the same grade of product.

I thought @jjrandorin was getting somewhat close to the warranty threshold. Maybe we'll see in a few years how Tesla handles it.

 

[jjrandorin]

I thought @jjrandorin was getting somewhat close to the warranty threshold. Maybe we'll see in a few years how Tesla handles it.

I have actually already been taken care of. Im not going to discuss the specifics (either here or PMs lol), but I will say that I am completely satisfied with the outcome.

Since this OP seems to want to insist, at a basic level " The warranty cant be what it states plainly there because other companies dont do it that way", I decided to take their advice and just "agree to disagree". If they do not want to believe the plain english there thats very clear, along with the footnote that explains exactly what it means, thats up to them.

 

[dareed1]

The PW spec indicates 13 useful kWh. And that goes down to 70% per the warranty. So let's assume that the average energy pulled out of the battery is 0.5*(13 + 0.7*13)=11kWh. Daily cycling of average 11 kWh is 37000/11 = 3363 cycles = 9.2 < 10 years.

Tesla policy is to limit the amount of PV capacity to 7.6kW (AC) per Powerwall. At our location, during the months of November through February, there are lots of days when 8kW of panels won't generate enough total energy to fully charge a Powerwall. In December 2021, our 8.16kW system had 20 days of 10kWh or less. That is the worst month, but over the course of the year, there will be at least 40 days in which a single PW wouldn't be fully charged--if we actually ran them that way. In fact we have two PWs, as recommended by Tesla, and I suppose there are a hundred days per year that we wouldn't make enough solar to support a full discharge/recharge cycle.

The point is that your calculation assumes an availability of energy to permit a discharge/recharge cycle every day of the year, and that is not a realistic possibility. And I think you'll also find that few PW owners actually discharge to below 20%--many of us want the PWs to provide some backup reserve.

 

[phil4791eng]

I’m not in CA but I’m hoping no power company would penalize people for producing clean energy that gets added to the grid. It seems like part of the solution to climate change and stress on the grid is more people with solar producing more than they need and sending the rest to the grid. I know there are politics involved so it’s likely not that simple, though.

Often there’s too much energy on the grid, primarily from wind and solar production, and the LMP is negative, meaning any energy put on the grid at that point the utility has to pay and not get paid for the energy going onto the grid. Too much energy can result in grid reliability issues, so it’s a burden.

 

[stevemc]

If you do not use, and send back, you get pennies on the dollar at true up. So, turn on the heaters, and if gas, you could always buy electric floor heaters

MIne Bitcoin!