11% shrinkage - is that normal?

11 % sounds a bit. High.

• The question is whether the charging stations take their own consumption into account.
• Reactive currents are not recorded there, but they are at the energy supplier.
• For technical reasons, losses already occur on the route to the charging station.
• There could be an additional device in the connection, which explains the power consumption.
• How is the grid structured? Which devices are installed?

1. whether the charging stations take their own consumption into account, I don't know.
2. i see the consumption of the individual users and i see the meter reading of the utility company's meter.
   3) The only additional device is a Fritzbox for load management.
3. we have 16 charging stations. It looks to me like one cable goes to a total of three distribution boxes. Spur lines go from the distribution boxes to the charging stations. Only four of the 16 charging stations have been used so far. The others are built for stock.
4. total consumption approx. 7,500 kWh per year, of which approx. 11% is wastage.

I had to do some more research myself. Without knowing the system and installation, I assume a few things.

1. router approx. 12 watts
2. switch approx. 8 watts
3. KUNBUS, RevPi Core 3 (load management) approx. 20 watts
4. line loss approx. 20 watts
5. other devices not known to me. 10 watts.

As a simple calculation, I can now use estimated consumption values for the calculation.
12 + 8 + 20 + 20 + 10 = 70 watts
70 watts x 1 hour = 70 watt hours (Wh)
70 Wh x 24 hours x 365 days / 1000 (for kilowatts) = 613.2 kWh per year

These are estimated values, but could correspond to the installation. If the charging stations then do not take their own consumption into account or my calculation does not fit, the deviation is quickly reached.