I have a single phase power supply to my property.
I’m using a shelly EM with 120A clamp to measure power consumption.
The energy usage seems to under counted, when I set up hourly / daily / weekly / monthly utility meters using the shelly as the source.
I want to use a utility meter because I have a peak and off peak tariff and would like a more accurate cost of usage per day / month.
For example, the last_period for the daily 'day rate ’ sensor shows 5.5907. The last_period for the daily ‘night rate’ shows 3.0314.
5.5907 + 3.0314 = 8.6221 kWh
The shelly app shows 8.92kWh for the last period. Since the energy dashboard is configured to only use the raw shelly data for now, it also reports 8.92kWh
8.92 - 8.62 = 0.3kWh
Yes, the difference is small, but why is there a difference at all?
The data is all coming from the same sensor. Is it just losing data when it does its reset each day?
As the time periods get longer, it seems to be more out.
For last week, it shows the utility meter (using shelly) shows 95.53kwH. The shelly app itself shows 98.88kWh.
3.35kWh is not being measured and reported. Why is this?