I've had a Tesla Powerwall for a bit now, and I've noticed that the "Solar Generation" number in the app is always lower than the solar generation number given to me by the MySunpower (solar system) app. For instance on 6/17 the Tesla App says 24.7 kWh were generated, while the Sunpower app says 39.6 kWh was generated. This is obviously a large difference. I only have one Powerwall, and it uses a sub panel to connect to most of the rooms in my house (not all), but it seems really unlikely that the few rooms I don't have are consuming 15 kWh per day (especially since they're bedrooms that no one is in during the day). Any ideas what is going on here?
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Powerwall Solar Generation always lower than Solar Company App
- Thread starter Talamar
- Start date
When I first had my system installed I was concerned that the Tesla app and the Solar Edge app were giving me conflicting numbers. I finally decided I didn't care: I have all the electricity I want for the whole house, including A/C, and charging the car, and I pay the utility only the monthly minimum. That's all that matters: all the free power I can use. (Including heating the entire oven just to bake one potato, and cranking the A/C to compensate for the oven.) I still don't know why the apps gave conflicting numbers. But I've stopped looking at the Solar Edge app because all that really matters is the Powerwall SoC on days of heavy overcast.
ArizonaJon
Member
I have a solaredge inverter. It always shows more than the Tesla app. Typically Tesla is 95% of solar edge. My installer thought it might be due to the fact Tesla only monitors one leg of my 10kW system but solaredge does both feeds. I also have 2 PWs but they feed the whole house.
charlesj
Active Member
I have Enphase inverters and a Tesla current sensor to read solar current.
Both reports are within a 0.2 % window and at times even closer.
Call both companies to see what is going on.
Both reports are within a 0.2 % window and at times even closer.
Call both companies to see what is going on.
jgleigh
Member
The solar inverter output is always balanced so they measure one leg and then double it. There might be a small error, but not the big difference you are seeing.
Here's the breakdown from the Tesla App and the Sunpower app.
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jgleigh
Member
Hard to say. The Tesla pictures don't highlight any obvious issues. The only odd thing I see if the Home load is very spiky and then drops to 0 kW.
What does the Power tab in the MySunpower app show you? Do your Grid exports from Tesla match what your utility is reporting? Also does your utility meter match what the real-time Grid values are in the Tesla app?
What does the Power tab in the MySunpower app show you? Do your Grid exports from Tesla match what your utility is reporting? Also does your utility meter match what the real-time Grid values are in the Tesla app?
A few more questions: how large is your solar system and is it a single inverter? The Tesla App solar generation curve looks normal, but it peaks at 3.1kW. It looks like it was a sunny day, and given it was June in SoCal that should be as high of a peak as you'll get (i.e. it should match your nameplate solar output, assuming no issues with roof orientation).
We can't tell where the SunPower chart peaks (need the Power tab for that), but looks to be more than 5kW. There's an odd bump at 8pm, but that might just be an issue with hourly binning.
I'm going to guess you have a 6kW system and Tesla is only showing half of that because of a CT misconfiguration.
We can't tell where the SunPower chart peaks (need the Power tab for that), but looks to be more than 5kW. There's an odd bump at 8pm, but that might just be an issue with hourly binning.
I'm going to guess you have a 6kW system and Tesla is only showing half of that because of a CT misconfiguration.
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I do have two systems, a small roughly 1.4kw system that came with the house, and a 5.5 kw system that we added. They use different inverters. The Tesla app does match pretty closely what my utility is reporting, and the meter does match the Tesla app when I compare them side by side. Here's that power tab from the Sunpower app, I had forgotten that was an option in the app!
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jgleigh
Member
I would guess the Tesla app isn't seeing the older system. It might not have a way to communicate with the Gateway or it wasn't included during the Gateway setup.
CrazyRabbit
Active Member
Tesla system should be setup to monitor whole house regardless that you have partial backup.
I have enphase system with tesla system and home consumption matches. Enphase doesn’t know about batteries or tesla solar, but home consumption matches.
I have enphase system with tesla system and home consumption matches. Enphase doesn’t know about batteries or tesla solar, but home consumption matches.
I've also noticed that solaredge reports higher generation than either Tesla or a kWh meter. I suspect that solaredge is measuring DC power into the inverter and both the kWh meter and Tesla measures AC power out of the inverter. The difference is the inverter conversion loss and, for total generation to date (approaching 6 years) is about 2.6%. However, comparing the past few days of Tesla and solaredge data shows a difference of about 4% when it should be about 1% according to the efficiency curve. Either the inverter is getting tired or Tesla's number is too low. I've just checked the generation meter which I last read 13 days ago and this has recorded 2.6% less energy than solaredge.
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