@bmah, i just tried this same test this morning under very similar circumstances as yours (see my prior post). however, my Delta inverter never came back on-line after i flipped the main. Powerwalls worked fine....but solar production never resumed. I waited a full hour. Do you think this behavior s something specific to the inverter? I am on 1.34.2. I just opened a case with Tesla Customer Care. thank you
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What is the current lead time for Power Wall installation?
- Thread starter voip-ninja
- Start date
@bmah, i just tried this same test this morning under very similar circumstances as yours (see my prior post). however, my Delta inverter never came back on-line after i flipped the main. Powerwalls worked fine....but solar production never resumed. I waited a full hour. Do you think this behavior s something specific to the inverter? I am on 1.34.2. I just opened a case with Tesla Customer Care. thank you
Sorry I have no clue whatsoever about this. As my son would say, I'm a total n00b.
(As long as I'm posting something: 50 minutes after the inverter turned back on, everything is still going as expected. The solar panels are now producing more than the house is using so it's starting to recharge the 78%-full batteries. I suppose at this rate I might be able to test the "shut off the inverter" functionality.)
Bruce.
When your solar doesn't come back online when you do a grid-down test you need to either look at the display on your inverter if it has one, or find out the frequency on the line. A simple Kill-A-Watt plug-in device can show you the frequency. I did this test on 3/26 for an hour and 5 minutes and the frequency was stable at 60.0Hz and the solar came back on very quickly. Probably closer to 1 minute than 5 minutes. During a series of real outages in November my system was running at 63Hz, which forced the solar offline. At the time, my SOC was relatively low, probably around 70%. IMHO, it should only raise the line frequency when the charging power approaches 5kW per Powerwall or the SOC gets high.
The OP did say that being able to charge from solar during outages is very important, though this has nothing to do with lead times.
Hey guys, how does Tesla size the number of powerwalls needed for an installation?
How do they back up some circuits but not others? Is it by use of a transfer switch?
It seems that it could be easier to just oversize the powerwall sizing and let it backfired the whole home and take manual steps to not use any high consumption devices during an outage.
How do they back up some circuits but not others? Is it by use of a transfer switch?
It seems that it could be easier to just oversize the powerwall sizing and let it backfired the whole home and take manual steps to not use any high consumption devices during an outage.
woferry
Member
When I went through the process it seemed more like the reverse, they asked me how many Powerwalls I wanted and then determined whether that would be enough for whole-house backup or only critical loads. Seems to largely be driven by the largest power loads, in my case they said one was sufficient for the whole house. The 5kW max continuous output of its inverter and 30A breaker used per-Powerwall sets the limit, effectively ~41A total or ~25A per phase in a split-phase system common in the US (using an 85% derating for the breaker amperage).
Yes, the Backup Gateway performs two functions, it contains the electronics used to collect all of the data for the Tesla app and control of the Powerwall(s), and also includes the automatic transfer switch to disconnect the grid during an outage. So if you have whole-house backup then all of the house circuits are moved to a breaker panel installed after the Gateway, if it's partial backup then the non-backed-up loads remain in a service panel on the grid-side of the Gateway. Looks like they do the same with generation, when they wired my panels they put one solar inverter on the grid-side of the Gateway and the other on the backed-up-side.
Easier on everything other than the wallet, sure.
Since they're not free sometimes the extra cost isn't worth it if all it takes is not using certain appliances during an outage. Room for more Powerwalls could be an issue, also.In my case, since I plan to add A/C to the house later, and will probably switch to an electric dryer when my current gas one dies, might get at least a plug-in hybrid vehicle the next time, etc., I'll probably need to add a second Powerwall later to keep the whole-house backup, but until then it just doesn't make sense to pay for a second one that I wouldn't be using right now.
What was the State of Charge on your Powerwalls during the test? They need to discharge below a certain threshold before they'll let the inverter start. I'm not sure what that exact threshold is, but it might also depend on the size of the PV array that's behind the backup gateway.
My Powerwalls were at about 55% during the most recent off-grid test, conducted by a Tesla technician, when they failed to lower the frequency to 60 Hz to support charging from solar.
So the issue from my perspective is we have conflicting accounts, yours doesn't work but it appears to work fine for other owners.
Now, this is a conundrum since partial home backup is the principal reason I would be purchasing Powerwall in the first place, at least for the near-term. Long term I would migrate my home into a non-peak model and use PowerWall to cut my electric bill after my net metering contract with the local utility expires.
Shygar
Member
My limited understanding is that you can configure what % the Powerwall charges and this can be done through the Tesla app.
So I had a rather information starved call with Tesla Energy sales just now.
- Powerwall installation costs 'almost always' run between $1,000-$3,000. LOL, okay.
- The energy sales rep 'thinks' that Tesla have their own in-house electricians that service my particular location.
- It is not possible to get in the reservation queue without a deposit but the deposit is refundable... although it's not clear if it's refundable after the installation costs have been estimated.
- There is no estimate on how soon Powerwall would be installed for me, other than "in most parts of the country the wait time for powerwall install is about 6-12 months".
Tesla does have their own electricians in the Denver area. They were great to work with when installing my solar, Powerwalls and signature wall connectors.
Perhaps then I'll just make a deposit and wait until they contact me and are ready to get into specifics.
I just spoke with Tesla customer support. They advised that in a grid outage, the PV/inverter won't come back online until the Powerwall capacity drops below 80%. They advised it was an approximate 15 minute polling interval from the Gateway. In my test this weekend, the battery never dropped below 95%. For my next test I will simulate a longer grid outage during the day and let the battery drop below the 80% threshold and see if the PV comes back on-line. Makes sense. Hopefully it actually works that way.
I wouldn't necessary believe the "80%" line. When I called, one of the phone reps told me that a grid-tied solar system will go down when the grid is down and that was "the point of having a grid-tied system". I tried telling her I have Powerwalls so that the solar would continue to work when the grid was down. She later admitted she was a "solar" phone rep and didn't know anything about Powerwalls. <sigh>
BTW, in my case, the Powerwalls were below 80%, having been drained down to 5% due to the extended outage.
The guy I spoke with was very competent and knowledgeable. He described expected behavior in detail in a variety of situations. I do believe that the system is designed to bring the PV back on-line in a grid outage when the batteries drop below 80%. That certainly doesn't mean that it willl actually work that as designed, which is why i'll be doing an extended test next weekend.
Well certainly it doesn't make sense that the array should be feeding juice in if the batteries are very close to topped out. Also, it would make sense if optimal max battery charging is about 80-90% with the batteries only going to 100% periodically for re-balancing or when preparing for a storm, etc.
I would probably normally keep the batteries around 75-80% anyways since my immediate use would not be to use the batteries for off peak charging.
