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My Small Solar Roof Project
- Thread starter aesculus
- Start date
Had my county inspection today and passed. The Tesla inspection coordinator came by early in the AM and dropped all the detail materials in a plastic bag and added the inspection card that was tucked in behind the inverter. He left the packet by the front door. He then took off to do the same for about 5 other locations within my general area.
One of my concerns was that there was no disconnect at the inverter to the sub panel and also the connection at the main panel was not marked for solar.
The building inspector stated I did not need the disconnect because my barn was not a habitable building (don't tell our horses that). Tesla made up a real neat placard to show where all the solar and batteries were on the property and where all the disconnects were. They placed this on my main panel. I also had them give me a red solar sticker for the conduit too just in case. Did not need it but will probably put it on as an extra safety flag.
Was supposed to have an AM inspection and the inspector showed up just a bit after 12PM. My inspector was very thorough and opened every panel including ones that the team did not touch (main and PW distribution). So the inspection went smoothly but I am glad I was there to answer any questions and provide some representation. The inspectors get a lot of jobs where nobody is there and if they have any questions or doubts the answer will be NO even though something might be explainable or they just need to make sure of intent.
So next step is the payment and PTO approval which probably won't happen until after the new year given the holidays and PG&Es schedules.
One of my concerns was that there was no disconnect at the inverter to the sub panel and also the connection at the main panel was not marked for solar.
The building inspector stated I did not need the disconnect because my barn was not a habitable building (don't tell our horses that). Tesla made up a real neat placard to show where all the solar and batteries were on the property and where all the disconnects were. They placed this on my main panel. I also had them give me a red solar sticker for the conduit too just in case. Did not need it but will probably put it on as an extra safety flag.
Was supposed to have an AM inspection and the inspector showed up just a bit after 12PM. My inspector was very thorough and opened every panel including ones that the team did not touch (main and PW distribution). So the inspection went smoothly but I am glad I was there to answer any questions and provide some representation. The inspectors get a lot of jobs where nobody is there and if they have any questions or doubts the answer will be NO even though something might be explainable or they just need to make sure of intent.
So next step is the payment and PTO approval which probably won't happen until after the new year given the holidays and PG&Es schedules.
Just one note: Tesla still has to figure out how to integrate this solar into the PW and gateway. Right now it would offset my house consumption because that is the CT it's being monitored on. They probably will need to move this conductor into the CT that measures the solar but it could be a small problem at night when we occasionally turn on lights. In that case it would show a negative solar production. Not sure how that would appear or be dealt with.
Putting a separate set of CTs on the barn is near impossible because the leg from the inverter to the panel is just an elbow. And even if they could its 400 feet from the barn to the PW gateway.
Putting a separate set of CTs on the barn is near impossible because the leg from the inverter to the panel is just an elbow. And even if they could its 400 feet from the barn to the PW gateway.
Quick update: Contacted Tesla and paid my balance via the phone. So next step is for them to notify PG&E that my system is operational and request that they release a PTO to me.
As an experiment I toggled the solar system on to make sure it was working before making the final payment. The only way I can measure the output is to look at the difference between what the house was drawing before and after the inverter was activated. This is because the Solar Roof panels are currently a part of the backup load circuit and not measured with the Solar CTs.
My house was drawing about 1.5 kW before I did the test. Note that it is a bit of a hazy day, at the worst solar potential and only 2.3 kW of panels were exposed to sunlight. The net with a .1Kw use at the Home indicated that portion of the solar roof was generating about 1.4 kW of power.
As an experiment I toggled the solar system on to make sure it was working before making the final payment. The only way I can measure the output is to look at the difference between what the house was drawing before and after the inverter was activated. This is because the Solar Roof panels are currently a part of the backup load circuit and not measured with the Solar CTs.
My house was drawing about 1.5 kW before I did the test. Note that it is a bit of a hazy day, at the worst solar potential and only 2.3 kW of panels were exposed to sunlight. The net with a .1Kw use at the Home indicated that portion of the solar roof was generating about 1.4 kW of power.
While I am waiting for my PTO and for Tesla to reconfigure my PWs to accommodate my new solar roof before I can do my summary report, I thought I would share a few pictures of the stuff we collected over the 10 days.
Both the tear off company and Tesla did a pretty good job of keeping the work area very clean and safe. Every workday they would tape off the area with caution tape and do a general cleanup of the work area and secure all of their tools and materials.
But still our standards had to be a lot higher as I reported above because of the danger or sharp objects getting embedded into horses hoofs etc. So we went out almost every night after the crew left and scanned the work area both visually and with magnets and a metal detector to pick up small bits or refuse. Here is what we collected (about 3 pounds worth) after the job was done.
The small bits of non metallic material are no big deal. But the metal shards, screws and nails could be a big problem. This is the metal left behind.
Notice some of the rusty bits were items that we had not retrieved when the barn was originally built and was buried a few inches below the surface. So we really scanned the area during this event.
Lastly one of the Tesla workers must have had a hole in their pocket because of the amount of one screw type we picked up. There were so many of these I put them in a plastic bag and put it back onto the parts buckets. I did not want Tesla to loose all of their profits on this job.
And yesterday Tesla came out with a large box truck to pick up the pallets, work bins and famous Tesla Roof Kits, but they ran out of room in the truck and left one more of the Roof Kits to be picked up later.
Both the tear off company and Tesla did a pretty good job of keeping the work area very clean and safe. Every workday they would tape off the area with caution tape and do a general cleanup of the work area and secure all of their tools and materials.
But still our standards had to be a lot higher as I reported above because of the danger or sharp objects getting embedded into horses hoofs etc. So we went out almost every night after the crew left and scanned the work area both visually and with magnets and a metal detector to pick up small bits or refuse. Here is what we collected (about 3 pounds worth) after the job was done.
The small bits of non metallic material are no big deal. But the metal shards, screws and nails could be a big problem. This is the metal left behind.
Notice some of the rusty bits were items that we had not retrieved when the barn was originally built and was buried a few inches below the surface. So we really scanned the area during this event.
Lastly one of the Tesla workers must have had a hole in their pocket because of the amount of one screw type we picked up. There were so many of these I put them in a plastic bag and put it back onto the parts buckets. I did not want Tesla to loose all of their profits on this job.
And yesterday Tesla came out with a large box truck to pick up the pallets, work bins and famous Tesla Roof Kits, but they ran out of room in the truck and left one more of the Roof Kits to be picked up later.
The last of the black special Tesla "kits" departed today. Monday I will contact Tesla to inquire about my PTO submission and also their plans for updating my Powerwalls for this installation.
Todays small update:
Tesla and I have been communicating about my two issues:
The PTO has now been filed. I am not sure I like how Tesla does this. We'll see what happens. First off the data they have to work with in my case is difficult. Every time you get a new PTO it resets the accounting for consumption at PG&E so you cannot just give them one bill with a yearly summary. Second when you install PWs your data is frozen on the PG&E page so that's no longer a source.
Adding to that Tesla seems to use what your bill states, not what your real consumption is. So if you have prior solar and don't show as much on the meter side, Tesla will take what the meter side sees which is going to be wrong because it's masked by your current solar. But then they add all your solar (new and old) to show your generation potential so it's an apples to oranges comparison. So to compensate they invent some fictitious consumption growth on the application so you don't blow out the 110% rule.
I called them on that but they through up their hands and stated PG&E does not look at it anyway.
The other issue I did not like and Tesla did correct, was that they added my PWs (10 kW) into the generation amount. I stated that they only did solar backup so they could not be considered generation. They took that amount off and stated they would see what PG&E said.
Good thing the world is now running on crazy math and unrealistic models. I would hate to think we all really knew what is happening in life and we knew what we were doing.
Now the good news. Thanks to @trautmane2 I am now able to see what my Delta inverter is producing day of and day before, if I stand in front of it and connect with a Delta app using Bluetooth LE.
As documented above, 2.3kW of my panels are facing South and another 2.9 kW are facing North. Those north panels are not going to be seeing any action until March at the earliest. But I was concerned if my system was actually producing a reasonable amount of power. So I did a bit of an experiment and fired it up to check the output. Its been either overcast or mostly overcast since the install. We had rain much of yesterday but today we had mostly sun with some clouds. According to the inverter it showed we reached a peak of about 2kW today which is about right for the 2.3Kw of panels that could contribute.
Tesla and I have been communicating about my two issues:
- Filing for the PTO
- Reconfiguring my PWs to accept this new solar roof
The PTO has now been filed. I am not sure I like how Tesla does this. We'll see what happens. First off the data they have to work with in my case is difficult. Every time you get a new PTO it resets the accounting for consumption at PG&E so you cannot just give them one bill with a yearly summary. Second when you install PWs your data is frozen on the PG&E page so that's no longer a source.
Adding to that Tesla seems to use what your bill states, not what your real consumption is. So if you have prior solar and don't show as much on the meter side, Tesla will take what the meter side sees which is going to be wrong because it's masked by your current solar. But then they add all your solar (new and old) to show your generation potential so it's an apples to oranges comparison. So to compensate they invent some fictitious consumption growth on the application so you don't blow out the 110% rule.
I called them on that but they through up their hands and stated PG&E does not look at it anyway.
The other issue I did not like and Tesla did correct, was that they added my PWs (10 kW) into the generation amount. I stated that they only did solar backup so they could not be considered generation. They took that amount off and stated they would see what PG&E said.
Good thing the world is now running on crazy math and unrealistic models. I would hate to think we all really knew what is happening in life and we knew what we were doing.
Now the good news. Thanks to @trautmane2 I am now able to see what my Delta inverter is producing day of and day before, if I stand in front of it and connect with a Delta app using Bluetooth LE.
As documented above, 2.3kW of my panels are facing South and another 2.9 kW are facing North. Those north panels are not going to be seeing any action until March at the earliest. But I was concerned if my system was actually producing a reasonable amount of power. So I did a bit of an experiment and fired it up to check the output. Its been either overcast or mostly overcast since the install. We had rain much of yesterday but today we had mostly sun with some clouds. According to the inverter it showed we reached a peak of about 2kW today which is about right for the 2.3Kw of panels that could contribute.
Still waiting on my PTO.
Today Tesla came out to see how the roof held up in the heavy winds we had. No problems.
Today Tesla came out to see how the roof held up in the heavy winds we had. No problems.
Another small update. As noted up thread my circuit for the barn solar already existed on the load side of the gateway. When solar was produced it was not reported in the app and actually offset the consumption of the house. If there was additional solar the delta did appeared in the app solar value along with the other two systems. This of course has a few issues with it.
So today my PM came out and added a new set of CT's that were installed in parallel with the existing solar CT's. So now the full solar production is shown in the app.
Interestingly I was worried that the home load would still be wiped out but somehow it is not. Why I cannot answer. This circuit is not only being monitored as a load, but as a production source too. What magic is going on behind the scene is a mystery to me.
My biggest issue now is that the new solar may not be able to participate in charging the batteries. I will have to run multiple tests to determine this. Could not do this today because our production is really limited by cloud cover and the Tesla guys needed to get on to real work.
The ultimate fix would be to have the backup load center swapped out for a larger one as there are no more breaker locations for the third solar circuit. If I add another PW this will be the case too, so I might just let that pass until (if) that time occurs.
So today my PM came out and added a new set of CT's that were installed in parallel with the existing solar CT's. So now the full solar production is shown in the app.
Interestingly I was worried that the home load would still be wiped out but somehow it is not. Why I cannot answer. This circuit is not only being monitored as a load, but as a production source too. What magic is going on behind the scene is a mystery to me.
My biggest issue now is that the new solar may not be able to participate in charging the batteries. I will have to run multiple tests to determine this. Could not do this today because our production is really limited by cloud cover and the Tesla guys needed to get on to real work.
The ultimate fix would be to have the backup load center swapped out for a larger one as there are no more breaker locations for the third solar circuit. If I add another PW this will be the case too, so I might just let that pass until (if) that time occurs.
The home load is not wiped out because the barn load is less than the barn solar. The additional solar you are seeing in the App is the barn solar minus the barn load. As long as the barn load is small, it won't matter. The additional barn solar can be used to charge your batteries.
If you want to see how it affects the numbers, take a heavy load out to the barn (like a space heater) and turn it on while your solar is otherwise fairly constant. The space heater load will draw from the barn solar, reducing your total solar in the App. House consumption won't change unless your space heater exceeds the barn solar.
We did try a small test by turning on about 300 watts of lights in the barn before we activated the solar. It did appear to account for that correctly.
The only change that was made today was to add another set of CTs on the barn and to plug it into the same CT input as the other two inverters. The barn is still an aggregate of the home load CT too. All the home loads are bundled on one breaker and that is being monitored by a single CT. So it is basically being monitored twice.
BTW I was also a bit confused about an additional set of CTs for the car charger. That is the only circuit that is not backed up. That set of CTs plus the aggregated home load represent all the circuits with potential loads.
So I will need to spend a fair amount of time with every possible perturbation of loads and solar to determine accuracy. But the initial set of tests turning off all solar and then back on one at a time plus scaling the house down to the absolute minimum was interesting.
SoCalSolarRoof
Member
Nice you have CTs. I can't get Tesla to give me CTs because I didn't get a power wall...
You can always buy some with a monitor. I've had a Brultech GreenEye for a long time (probably better options these days), and have CTs on each of my circuits with the ability to monitor consumption and production (for the backfeed).
SoCalSolarRoof
Member
Well today I got a nice email from Tesla:
Maybe someday I will actually get a PTO.
My install was complete back on 12/21, inspected and paid for. The first PTO submission was on 1/22. For the longest time my account never stated I had paid. That is the only difference I can see today from before. The Utility box is still a solid black and not a check mark.
Maybe someday I will actually get a PTO.
Enginerd
Member
Rookie question. Why would the solar be unable to charge the batteries? With basically one side illuminated, is the nominal/peak solar voltage below the 50V PW voltage? Or does the PW only charge from a 120/240 VAC source (not DC)?
It depends on how the circuit is set in the backup load center. If external it would not charge. Mine is internal so it should.
But with two CT's monitoring the circuit at the same time (one as a backed up load and one as solar) I am not sure what could happen. Its still under software control.
So this weekend it should be sunny enough and hopefully I won't forget to do the test in the AM before the PWs reach 100%. I need to shut my other two solar sources off and then make sure the solar roof can still charge.
PTO finally awarded after 4+ months. What a fiasco. I finally had to step in to get in the middle of this as Tesla really screwed up submitting the application and details and PG&E was super slow responding and acting on new information. The entire process is a CF IMHO. This is my 4th PTO so I know what has to take place and how easy it really should be.
Well now that my PTO is active and I can legally send power back to PG&E, my 5+ kW solar roof is putting out about 500 Watts at 3:30 PM on a sunny, cloudless day at 80* F.
During a "test" at the end of March I saw 3 kW at the same time. With my roof angles it should be better now.
So it's off to Tesla land next week to see if I can get them to debug it.
If its not one thing its another.
During a "test" at the end of March I saw 3 kW at the same time. With my roof angles it should be better now.
So it's off to Tesla land next week to see if I can get them to debug it.
If its not one thing its another.
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