I got new panels and a new inverter installed recently. My previous inverter did not have a monitor app for solar so that was my reason to get Sense. Now that I have a SolarEdge inverter with an app to monitor I can do a comparison. I like the real-time data from Sense a lot. SolarEdge has sometimes a 12 minute delay. When I check my production it looks like that SolarEdge solar production is way higher then what Sense tells me. Looking for input to explain the numbers from Sense vs SolarEdge when it comes to production. The images are taking seconds in between and should tell the story.
First important note - never compare measurements in kW (power) vs. measurements in kWh (energy). Use the Solar W (124W or 0.124kW here) measurement in the top of the Solar Trends panel when you want to compare against kW on the SolarEdge side.
Another thing I have found that makes current-day comparisons difficult is that the trends view of the Sense app does not show the current hour (you can see this yourself in that there are bars for 12AM, 1AM, …, 8AM, but no 9AM bar). Since your screenshots are about 3/4 of the way through the current hour, you’re missing all of that data from the Sense app (until 10:00 local time). The SolarEdge app probably shows more recent current-day production (I see it says as of 12 minutes ago, where the Sense app is effectively as of 46 minutes ago from your screenshots).
I bet if you look at Sense right after the top of the hour (and make sure that the most recently-completed hour is there), the production will be much closer to what SolarEdge is reporting.
Great find will do another comparison at 1 pm. To [kevin1] I was looking at the left part of the screen the production today is at 5.04 Kwh vs Sense production 2.7 Kwh. Do I have to add 20% to my total production in order to get the correct solar production at that time frame?
If the solar production is fairly constant throughout an hour, you could get a decent approximation for the missing usage by taking what SolarEdge (or Sense, for that matter) returns as current kW production and multiplying by the fraction of the hour-in-progress (from your previous example, that would have been about 0.75) and adding that amount to the total kWh for the day so far. To be fair to both systems, you’d also want to add current kW times 0.2 (for the 12 minutes missing from SolarEdge). Alternatively, if you happened to hit both apps at a time where their last refresh was the same time (e.g. if SolarEdge were always 12 minutes behind, the 12th minute of every hour should have both systems line up).
Constant solar production is only likely if it’s a very clear day and you’re late enough in the morning/day that your system is either operating at near-maximum or is clipping. Unless it’s cloudy enough that your solar graph (like on the power meter view) is up and down all over the place, it may not matter for getting numbers close enough for a comparison.
@rverwij, try checking a few minutes after each hour. The Sense Solar Production reading saying 2.7kWh only gets updated every hour (a couple minutes after the hour), while your SolarEdge is probably updated every 12min as you suggest. If I look at my Tesla app reporting on my SolarEdge production vs. my Sense data for yesterday, they are fairly close - 18.8kWh from SolarEdge and 17.6kWh for Sense, or a difference of about 6%.
I hae done some correlation studies of SolarEdge vs. Sense vs. my revenue meter (utility meter) and Sense w Solar is far more accurate than using the SolarEdge measurement. I believe that SolarEdge and Sense produce difference values for a couple of reasons.
- SolarEdge does the measurement upstream from the Sense measurement inside my main panel. There are power losses after the SolarEdge measurement before the power arrives at the main panel.
- The SolarEdge measurement likely also excludes the power required to run the inverter itself.
Most solar users on this forum tend to see their Sense production coming in 3-6% lower than their inverter measurement.
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@rverwij - Something is definitely off… I was also looking at the same figures you were looking at (the 5.04kWh “Production Today” versus Sense’s 2.7 Production)…
I also have the SolarEdge and Sense app, and they report far closer numbers than what you are finding… Generally speaking, my SolarEdge app reports about 2-3% higher numbers… I have been told that this is because the SolarEdge app is taking the measurement from the inverter (which I am told consumes some of that energy), and the Sense device is downstream which reports the 2-3% loss between the inverter and my main panel…
I am not sure how accurate that is, but that is what I have been told…
There’s no way I can explain the difference you are seeing though…
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I waited for the sun to set to get another reading. Sun sets at 7 PM and I waited till 8:40PM. It looks like the readings are close enough. I did not know that Sense refreshes the production data every hour and SolarEdge has different updates schedules.
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Nice - so your SolarEdge is about 3% more optimistic than Sense. That’s typical.
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