On your energy supplier's annual statement, you will see the amount of 'feed-in power' (in Dutch: teruglevering). This is usually a lot lower than the amount of power generated by the panels, which you can read on your inverter or on your monitoring app. Why is that?
No feed-in: the power from the panels goes directly to the users
Feed-in: the power goes past the kWh meter to the grid
The power generated by your panels will initially flow to all the appliances in your home that are using energy at that time. Only when more energy is produced than consumed at the same time, will the surplus be fed back to the grid via the energy meter. Only that portion is registered as feed-in.
It is therefore normal that the amount of energy fed into the grid (in kWh) is significantly less than the amount of energy produced. At the same time, the amount of energy purchased from your energy supplier should also be less than before the panels were installed. Below is an example situation.
An average family has an annual consumption of 3,500 kWh. So without solar panels, they get an annual bill from their power company for 3,500 kWh.
They decide to purchase a PV system of 8 panels of 327 watt-peak, i.e. 2.6 kWp. The panels are nicely south-facing, producing about 2,200 kWh of energy per year.
Of this energy, about 40% is used directly in the house, a total of 880 kWh. The remainder, 1,320 kWh, flows back to the grid and is registered by the kWh meter as 'feed-in'.
On the new annual statement, they now see: consumed energy: 2,620 kWh (which is 880 kWh less than before the panels were installed), and feed-in energy: 1,320 kWh. Because of the net metering system, they end up paying only for the difference between the two, or 1,300 kWh.
