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TBrownTX
Active Member
Since install, I've seen daily production in the 40-50 kW range on good sunny days. A handful of times I've seen my inverter putting out the full 7.6 kW, but really have not seen any clipping. I have 24 panels, with all but 5 facing south (5 face SE).
resurrection of thread...
Tesla keep doing this things. I have 3 strings, but to inverter comes 2 pairs.
Those two parallel string resides on different slopes of roof... WTF.
Tesla ? did you save $1/ft on 20 feet long ? really $40 ?
This is how wiring done on roof, before down in 3/4 EMT to inverеter.
Tesla keep doing this things. I have 3 strings, but to inverter comes 2 pairs.
Those two parallel string resides on different slopes of roof... WTF.
Tesla ? did you save $1/ft on 20 feet long ? really $40 ?
This is how wiring done on roof, before down in 3/4 EMT to inverеter.
Same things happened to me - they wired East & West panel in parallel. Realistically, I think it only results in a small hit in production ... but to do that for 20+ years to save on a couple dozen feet of 10 gauge wire - WTF Tesla?!? Plus you lose some troubleshooting ability if you have an issue.
Bummed I missed this on the Set Plan because I would have certainly pushed back ... and heck, would have offered to pay for the cable!
Bummed I missed this on the Set Plan because I would have certainly pushed back ... and heck, would have offered to pay for the cable!
It could be worse. You could be like many with a true NORTH string stuffed into an east/south-ish east string and hear constant “it’s not a problem”’s from tesla.
Matt-FL
Member
My thoughts on this, as I'm apparently in the same boat as many of you.
Start with my system:
(51) T400 panels
(29) south facing
(11) east facing
(11) west facing
(2) 7.6 inverters
(1) Gateway 2 - whole house panel backup
(4) Powerwall 2
Original design had half of east facing on a string, the other half on a second string (split of east facing string was - I think - because I provided shading pictures with my initial pictures/documentation). Half of south facing on a string, connected to inverter 1.
West 11 on a string, most of the rest of south facing on a string, then a few south facing on another string (even/odd maybe?)
That design changed once the installers arrived.
Most (not sure if 22, 24 or 26) south facing panels are in two strings combined parallel to one inverter. The remaining odd number of panels on another string on the same inverter.
East + west facing are on separate strings going to the second inverter.
Not being as TMC educated as I am now, the installers gave good reasons behind doing it that way. However, now that I am TMC educated, I sincerely believe that they changed the design for no other reason than to simplify installation.
Does my system perform up to Tesla's estimates? It overproduces by a significant margin. Tesla estimated 22,951kWh per year, in the last 365 days it produced 28,549kWh. A decent 20% over.
In that regard, I'm happy. On the other hand, I think the system would be producing a bit more if it was balanced better. I have two inverters, one that is full out racing around a track, and the other that is riding a beach cruiser around town.
Is it enough to call Tesla and complain? No, having a significant discount on the overall installation comes with some downsides, this being one of them. If I had paid the extra 50% to have another installer do the work, well, then I'd have other things to complain about.
The system is working to my expectations, the install was done really well (other than the design change). I think the only downside is, well, you hear about people having range anxiety with EVs? I think I have cloud anxiety
.
Start with my system:
(51) T400 panels
(29) south facing
(11) east facing
(11) west facing
(2) 7.6 inverters
(1) Gateway 2 - whole house panel backup
(4) Powerwall 2
Original design had half of east facing on a string, the other half on a second string (split of east facing string was - I think - because I provided shading pictures with my initial pictures/documentation). Half of south facing on a string, connected to inverter 1.
West 11 on a string, most of the rest of south facing on a string, then a few south facing on another string (even/odd maybe?)
That design changed once the installers arrived.
Most (not sure if 22, 24 or 26) south facing panels are in two strings combined parallel to one inverter. The remaining odd number of panels on another string on the same inverter.
East + west facing are on separate strings going to the second inverter.
Not being as TMC educated as I am now, the installers gave good reasons behind doing it that way. However, now that I am TMC educated, I sincerely believe that they changed the design for no other reason than to simplify installation.
Does my system perform up to Tesla's estimates? It overproduces by a significant margin. Tesla estimated 22,951kWh per year, in the last 365 days it produced 28,549kWh. A decent 20% over.
In that regard, I'm happy. On the other hand, I think the system would be producing a bit more if it was balanced better. I have two inverters, one that is full out racing around a track, and the other that is riding a beach cruiser around town.
Is it enough to call Tesla and complain? No, having a significant discount on the overall installation comes with some downsides, this being one of them. If I had paid the extra 50% to have another installer do the work, well, then I'd have other things to complain about.
The system is working to my expectations, the install was done really well (other than the design change). I think the only downside is, well, you hear about people having range anxiety with EVs? I think I have cloud anxiety
.
Jeremy3292
Active Member
Can you explain further what you mean and what the cause & effect is r.e. strings in parallel?
Matt-FL
Member
I honestly don't have an issue with the serial strings wired in parallel. I know that is a common configuration. My biggest concern is the unbalanced nature of my panels - 29 on one inverter, all south facing so full production during the day, then 22 on another inverter, half east and half west. So maybe a decent production at the noonish hours, but then mostly 11 producing at a time.
Serial strings in parallel increase amperage but voltage remains the same as each serial string.
I'm pushing tesla to fix it. For 2 months, so far nothing, promises to review plan, engineers do not see issue, we are not customer facing dept... all that bullshit passed. Waiting for call to discuss "Pros" of such design from design team/engineer. Hope I'm not to stupid to miss understanding such amazing benefit of wiring strings in parallel on inverter with free MPPT ports.
I asked several times about this and got the run-around ... so let me know if you figure out the magic words to make it happen!
And yes, I have an open MPPT port also.
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