Solar roof production before PTO vs after PTO

[charlesj]

My company had to replace the meter so it would go backwards. Perhaps that is the case as maybe not every customer has such a meter, digital or the older analog wheel type.

 

[twowheels]

As of last year they were not limiting. My pre-PTO numbers were no different than post-PTO. Installed Aug 29, 2022, PTO Jan 27, 2023.

My lead Tesla installer turned the system on and said I could leave it on since I had batteries, but (cue Keystone cops' music, once again ) if I was pushing a lot of power back, to switch to off-grid mode.

When my utility came out to inspect, he didn't say anything about it being powered. He did his inspections, checked grounds and neutrals, then swapped the meter for a 2-way and was on his way.

As a newby, this all adds to my confusion. I was just installed with panels and powerwalls around Sept 2023. I've been producing since then. So when I hear people talking about switching PTO on their own, I don't understand why. I was told by a Tesla person that once PTO was given, my system would generate more power. From what you're saying, that's not true? It also appears in years past, solar system were kept off (not generating anything) till PTO was received? Now I'm not sure if I'll generate more once I receive PTO. You say/imply I won't? I was also told that SCE doesn't come out and check anything. They just give permission. I'm had fire inspection and city inspection passed.

 

[jjrandorin]

As a newby, this all adds to my confusion. I was just installed with panels and powerwalls around Sept 2023. I've been producing since then. So when I hear people talking about switching PTO on their own, I don't understand why. I was told by a Tesla person that once PTO was given, my system would generate more power. From what you're saying, that's not true? It also appears in years past, solar system were kept off (not generating anything) till PTO was received? Now I'm not sure if I'll generate more once I receive PTO. You say/imply I won't? I was also told that SCE doesn't come out and check anything. They just give permission. I'm had fire inspection and city inspection passed.

Instructions / info you are seeing from a year ago may or may not apply to you. My recommendation would be to not try to evaluate solar production until after you get PTO. Tesla now installs systems that dont export until PTO, so it will stop your production if there is excess production that "would" export because it has no where to go.

So, Since you just got installed in September, just enjoy it, read (but dont stress) and dont worry about evaluating performance until PTO.

 

[charlesj]

As a newby, this all adds to my confusion. I was just installed with panels and powerwalls around Sept 2023. I've been producing since then. So when I hear people talking about switching PTO on their own, I don't understand why. I was told by a Tesla person that once PTO was given, my system would generate more power. From what you're saying, that's not true? It also appears in years past, solar system were kept off (not generating anything) till PTO was received? Now I'm not sure if I'll generate more once I receive PTO. You say/imply I won't? I was also told that SCE doesn't come out and check anything. They just give permission. I'm had fire inspection and city inspection passed.

I'd make sure to check the utility meter what you produce more than you need to see if it shows decreasing number instead of increasing numbers, in other words, bi-directional already.

 

[wwu123]

I'd make sure to check the utility meter what you produce more than you need to see if it shows decreasing number instead of increasing numbers, in other words, bi-directional already.

I have read online, though I don't know if it's true - even bi-directional meters actually still keep two counters regardless of what's shown on its display, one that keeps track of imports (positive direction), the other exports (negative direction). And thus, even if you have the proper meter or smartmeter, if the utility has not configured an existing account for NEM, then there is a risk that pre-PTO folks can get double-billed, as their exports are also charged as if they are imports.

Have not read any reports of this happening to pre-PTO folks recently, but did a couple of years ago...the fix wasn't the utility swapping out the meter, but rather configuring the billing for NEM once PTO happens.

 

[charlesj]

I have read online, though I don't know if it's true - even bi-directional meters actually still keep two counters regardless of what's shown on its display, one that keeps track of imports (positive direction), the other exports (negative direction). And thus, even if you have the proper meter or smartmeter, if the utility has not configured an existing account for NEM, then there is a risk that pre-PTO folks can get double-billed, as their exports are also charged as if they are imports.

Have not read any reports of this happening to pre-PTO folks recently, but did a couple of years ago...the fix wasn't the utility swapping out the meter, but rather configuring the billing for NEM once PTO happens.

Meters constantly reports usage back to company. If they supply energy, the meter on it will increase and company will know where it started and when there is another change of direction, or nothing if self using. Don't need a second hidden meter inside as all the data is there on the meter, no? Forward going is import, backward going is export. I see that all the time.
Now on the old meter, even by directional, it didn't report, meter reader read the numbers, unknown except total usage or total export if it was less than previous reading.

At least he would know if he is exporting which way is it showing on the meter window.

 

[wwu123]

Meters constantly reports usage back to company. If they supply energy, the meter on it will increase and company will know where it started and when there is another change of direction, or nothing if self using. Don't need a second hidden meter inside as all the data is there on the meter, no? Forward going is import, backward going is export. I see that all the time.
Now on the old meter, even by directional, it didn't report, meter reader read the numbers, unknown except total usage or total export if it was less than previous reading.

At least he would know if he is exporting which way is it showing on the meter window.

You would think that, I know my local Zigbee HAN device gets realtime net power updates every 10 seconds or so locally. But does the utility actually transmit that data frequently to their own logging device, whether over Zigbee or cell? Actually since in California I believe the mandated net interval for calculating NBC's and exports is minimum 15 minutes, so even a single net reading every 15 minutes would be sufficient for their net metering purposes, to keep track of both exports and imports for billing purposes.

I'm by no means an expert, but it turns out there is a difference between a physical "net" meter and a bi-directional meter, regardless of whether it is communicating. The former just records with a single meter that can go forward and backwards, the latter actually keeps track of +kwh, -kwh, and net kwh. My PG&E meter is a Landis+Gyr model that is an actual bi-directional meter - the physical display only shows NET kwh, but it can be configured to also show DEL (delivered, i.e. +kwh) and REC (received, i.e. -kwh). Home automation open-source projects have thus far been unable to reverse engineer the actual transmitting data streams though, so again it's unclear if the +kwh and -kwh is actually being sent back to PG&E's home base, and if it is, whether they archive it or just retain the net (which is all that is in historical Green Button data).

My Landis-Gyr meter was actually swapped out with another almost identical one a few minutes ago, and from that moment on, my downloadable Green Button data went from 15 minute intervals to 60 minute intervals. Since there is a configurable parameter in the meters themselves, I suspect the meters only end up sending back data that infrequently over their WAN - otherwise there was no reason my interval data would suddenly be re-configured during a meter swap-out.

 

[charlesj]

You would think that, I know my local Zigbee HAN device gets realtime net power updates every 10 seconds or so locally. But does the utility actually transmit that data frequently to their own logging device, whether over Zigbee or cell? Actually since in California I believe the mandated net interval for calculating NBC's and exports is minimum 15 minutes, so even a single net reading every 15 minutes would be sufficient for their net metering purposes, to keep track of both exports and imports for billing purposes.

I'm by no means an expert, but it turns out there is a difference between a physical "net" meter and a bi-directional meter, regardless of whether it is communicating. The former just records with a single meter that can go forward and backwards, the latter actually keeps track of +kwh, -kwh, and net kwh. My PG&E meter is a Landis+Gyr model that is an actual bi-directional meter - the physical display only shows NET kwh, but it can be configured to also show DEL (delivered, i.e. +kwh) and REC (received, i.e. -kwh). Home automation open-source projects have thus far been unable to reverse engineer the actual transmitting data streams though, so again it's unclear if the +kwh and -kwh is actually being sent back to PG&E's home base, and if it is, whether they archive it or just retain the net (which is all that is in historical Green Button data).

My Landis-Gyr meter was actually swapped out with another almost identical one a few minutes ago, and from that moment on, my downloadable Green Button data went from 15 minute intervals to 60 minute intervals. Since there is a configurable parameter in the meters themselves, I suspect the meters only end up sending back data that infrequently over their WAN - otherwise there was no reason my interval data would suddenly be re-configured during a meter swap-out.

I can agree to all.
I am thinking that @twowheels could see what the utility meter is showing and what his app is showing at that second, how his export or intake per app compares to the meter. For me, it shows up on meter rather fast if it has to import or still exporting when oven, a large load, is turned on. If he is pre-PTO this might give him a clue how things are working pre-PTO, I would think.

 

[Matt-FL]

As a newby, this all adds to my confusion. I was just installed with panels and powerwalls around Sept 2023. I've been producing since then. So when I hear people talking about switching PTO on their own, I don't understand why. I was told by a Tesla person that once PTO was given, my system would generate more power. From what you're saying, that's not true? It also appears in years past, solar system were kept off (not generating anything) till PTO was received? Now I'm not sure if I'll generate more once I receive PTO. You say/imply I won't? I was also told that SCE doesn't come out and check anything. They just give permission. I'm had fire inspection and city inspection passed.

Something to keep in mind, systems without batteries were kept off until PTO as excess would always be pushed to the grid. That could be where you heard of systems kept off, and that is still true to today.

 

[twowheels]

I'd make sure to check the utility meter what you produce more than you need to see if it shows decreasing number instead of increasing numbers, in other words, bi-directional already.

The meter appears to be working correctly. Not surprisingly, my panels don't appear to be producing anymore than they did before receiving PTO.

 

[twowheels]

I can agree to all.
I am thinking that @twowheels could see what the utility meter is showing and what his app is showing at that second, how his export or intake per app compares to the meter. For me, it shows up on meter rather fast if it has to import or still exporting when oven, a large load, is turned on. If he is pre-PTO this might give him a clue how things are working pre-PTO, I would think.

I'm only judging by the Tesla app. Yes, I can see when a microwave oven is on or the AC. Doesn't seem like anything changed after PTO.

 

[Iain]

Today I received PTO today and as soon as I slid the permission to export it immediately drained both PW3’s to zero and today I have produced 35Kw and it’s all gone to the grid.