I tried to do a search on this, but the wording is tricky, and I was coming up empty:
tl;dr:
We have a huge mismatch between the Tesla app "sent to grid" figure (91kWh) and our upstream "sent to grid" (41kWh) meter. Given our setup (see ASCII diagram below), is our house capable of consuming excess solar before any is sent back further upstream to the grid and getting registered by the upstream meter?
Background
We've had our small 4.1kW + 2 Powerwall system running on our detached garage/home office since October 2019. We intentionally eat most of what we grow, but now that daylight has returned to the northeast AND we're not driving due to self-quarantine, we're sending "a lot" (for us) more solar energy back to the grid.
The Numbers
Our "Lifetime > TO GRID" value in the Tesla app shows 91kWh (80kWh in 2020).
We have a separate, dedicated backfeed meter installed (thanks, Pennsylvania!) and the day they installed it, it read 0kWh. Today it reads 41kWh, or less than HALF of what the Tesla app claims has been sent back to the grid.
Help plz!
Does anybody have any personal data they can share that might help shed some light on whether this is "normal" or "abnormal" ?? I can understand a slight deviation of these values due to losses and rounding, but less than half seems wildly off to me.
Possible explanation?
I have one idea that this could explain what might be going on and it would be related to our somewhat unusual setup that involves our single grid feed coming in to a single meter, then splits into two 200 amp "Main House" and "Garage" breakers/feed (400A total service from grid).
Having hardly any understanding of electricity, does this theory make any sense?
I'm wondering if perhaps some portion or nearly all of our upstream solar from the garage is actually getting consumed by the main house before any additional overages are sent further upstream and hit our upstream meter? Our main house daytime instantaneous draw tends to be very low (0.2kWh - 2kWh) and consistent (about 18kWh /day) while the garage tends to be very "peaky" (0.2kWh idle - 12kWh instantaneous with car charging, on-demand electric hot water, electric heat pump, etc.)
Our setup
tl;dr:
We have a huge mismatch between the Tesla app "sent to grid" figure (91kWh) and our upstream "sent to grid" (41kWh) meter. Given our setup (see ASCII diagram below), is our house capable of consuming excess solar before any is sent back further upstream to the grid and getting registered by the upstream meter?
Background
We've had our small 4.1kW + 2 Powerwall system running on our detached garage/home office since October 2019. We intentionally eat most of what we grow, but now that daylight has returned to the northeast AND we're not driving due to self-quarantine, we're sending "a lot" (for us) more solar energy back to the grid.
The Numbers
Our "Lifetime > TO GRID" value in the Tesla app shows 91kWh (80kWh in 2020).
We have a separate, dedicated backfeed meter installed (thanks, Pennsylvania!) and the day they installed it, it read 0kWh. Today it reads 41kWh, or less than HALF of what the Tesla app claims has been sent back to the grid.
Help plz!
Does anybody have any personal data they can share that might help shed some light on whether this is "normal" or "abnormal" ?? I can understand a slight deviation of these values due to losses and rounding, but less than half seems wildly off to me.
Possible explanation?
I have one idea that this could explain what might be going on and it would be related to our somewhat unusual setup that involves our single grid feed coming in to a single meter, then splits into two 200 amp "Main House" and "Garage" breakers/feed (400A total service from grid).
Having hardly any understanding of electricity, does this theory make any sense?
I'm wondering if perhaps some portion or nearly all of our upstream solar from the garage is actually getting consumed by the main house before any additional overages are sent further upstream and hit our upstream meter? Our main house daytime instantaneous draw tends to be very low (0.2kWh - 2kWh) and consistent (about 18kWh /day) while the garage tends to be very "peaky" (0.2kWh idle - 12kWh instantaneous with car charging, on-demand electric hot water, electric heat pump, etc.)
Our setup