I have a 12Kw system installed about 6 months ago in Minnesota. I hadn't checked until now but I am seeing a big discrepancy between what the App shows and the readings from the Utility (Xcel). For example in November, the app shows 504 Kwh vs 308 from utility. In December, it is 304 Kwh vs 129 from utility. What could be going on here?
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Tesla Solar App vs Utility meter
- Thread starter nasirmd
- Start date
There could be a few things that cause this. One is, the utility doesnt know what power your home has consumed. It only knows how much is imported and exported.
The tesla app should know all solar produced, while the utility will only know what you sent out to them, and bought back from them.
Another could be mis configured CTs which capture production. Still another could be difference in billing dates, Unless your utility bill date is from the 1st through the end of the month, vs some day in between.
The tesla app should know all solar produced, while the utility will only know what you sent out to them, and bought back from them.
Another could be mis configured CTs which capture production. Still another could be difference in billing dates, Unless your utility bill date is from the 1st through the end of the month, vs some day in between.
Thanks for your response.
I downloaded the daily data from the Tesla App and aligned it to the billing dates from the Utility so there should be very little/no difference in my comparison.
The utility (Xcel) is supposed to give me yearly renewal energy credit for total solar production. I would have thought that their meter will capture all energy produced.
I am new to this so I don't know if the PV meter reading on the bill is the difference in production/consumption or the full production. If it is only the difference then I wonder how I will get the annual renewal energy credit under the state program. There are only 2 meters in the house.
The contractor Tesla hired had messed the original install. I am wondering if they messed up something else like the mis-configured CT that you suggest.
Those incentives are usually for energy sent back to the grid, not all energy produced. I would check it again. Your utility doesnt know about your solar production, they know what you send to the grid, which in most cases is the energy left over that your home does not consume at generation.
It sounds like he might have a separate generation meter for the PV.
charlesj
Active Member
@nasirmd how many meters do you have?
Your Tesla app most likely shows your solar generation. Then, your house uses energy at time of generation period. Any extra generation goes to the grid. The utility will read that as received . If your home uses more than is generated by solar utility meter will show that as delivered to you.
From your data, it appears that you used more energy than what you generated in that time period if the utility billing date is the same period as the Tesla app summation period.
One way to get an idea of what your home uses is to check your historical pills for the same months before solar unless you added more electricity consumed equipment like an electric or plug in car. If no real usage changes occurred, then it just depends on historical weather, heating or cooling changes.
Your Tesla app most likely shows your solar generation. Then, your house uses energy at time of generation period. Any extra generation goes to the grid. The utility will read that as received . If your home uses more than is generated by solar utility meter will show that as delivered to you.
From your data, it appears that you used more energy than what you generated in that time period if the utility billing date is the same period as the Tesla app summation period.
One way to get an idea of what your home uses is to check your historical pills for the same months before solar unless you added more electricity consumed equipment like an electric or plug in car. If no real usage changes occurred, then it just depends on historical weather, heating or cooling changes.
To give my $.02, I just checked yesterdays readings from SRP (Arizona), and they have us producing 35kW, using 28kW and Exporting 7kW. The Tesla app shows us producing 35kW, using 36kW and exporting only 2kW! So, a bit of a discrepancy there. I guess I will use the app only for monitoring production.
I have one net meter. Monthly electric bill shows how many Kwh they sent me at night and how many Kwh I sent them during the day. They calculate the difference for the charge or credit. They do not know how much solar I generated/consumed, only the excess I sent them, if any. There's certainly no excess solar in the winter.
We have both... We have Net Metering for excess production and we have a state mandated program called Solar*Rewards where I get credit for all renewable energy produced in lieu of the Utility getting renewable credits from my solar panels to meet their renewable targets. In order to do the 2nd thing, the Utility has to know how much my panels produced overall before consumption.
Historical data will be tricky since I purchased a Tesla in the last year so my electric consumption has gone up.
I am going to start by calling the Utility to find out what they are measuring.
charlesj
Active Member
Could you post pictures of those meters?
Did power company require that many meters?
Here is a pic. 2 on the left are for the panels and Powerwalls the other is the Main.
Attachments
charlesj
Active Member
Great, thanks. Is this before going online as I don't see an actual meter in those boxes.
Was that a requirement or your request?
This was before going online. SRP came and put in their own meters in all 3 spots. We are on E-13 plan which gives us $.03 per kW fed back. But in winter they charge $.08 off peak and $.10 on peak. Summer peak is $.27. But, no demand charges
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