An electricity meter measures how much electricity is consumed from the network at the place of consumption and how much electricity is supplied to the network. Data is measured at intervals of either one hour or 15 minutes, depending on the meter and the method used for storing metering data.
How is metering data calculated?
The electricity meter measures electricity volumes separately for each phase and quantities flowing in the same direction are added together.
For example: 5 kWh of electricity is consumed on one phase, 2 kWh on another phase and 3 kWh of generated electricity is supplied to the network on the third phase. For that period, the meter records:
- 7 kWh consumed from the network,
- 3 kWh supplied to the network.
Net metering data
From 1 August 2026, in accordance with the Electricity Market Act, electricity invoices for places of consumption equipped with a bidirectional meter will be based on net metering data.
Net metering data is calculated where the meter measures electrical energy in two directions: consumption from the network and supply to the network. In such cases, the difference between the amount of electricity consumed and the amount supplied to the network is calculated for each metering period.
The introduction of net metering data does not change how the meter measures electricity. If your place of consumption is equipped with a bidirectional meter, net metering data will be calculated automatically and you do not need to take any action. This is a standard calculation method that is applied automatically and uniformly to all customers with the relevant type of meter.
In addition to the data measured by the meter, we also provide sellers of electricity with net metering data via the data exchange platform.
How is net metering data calculated?
Net metering data is calculated for each 15-minute metering period.
If more electricity is consumed from the network than supplied to the network during a metering period, net consumption occurs.
Example of net consumption:
- 7 kWh was consumed from the network during the metering period;
- 3 kWh was supplied to the network;
- subtracting these amounts (7 kWh – 3 kWh) results in net consumption of 4 kWh;
- the amount of net supply to the network is 0 kWh.
If more electricity is supplied to the network than consumed from the network during a metering period, net supply to the network occurs.
Example of net supply to the network:
- 2 kWh was consumed from the network during the metering period;
- 8 kWh was supplied to the network;
- subtracting these amounts (8 kWh – 2 kWh) results in net supply to the network of 6 kWh;
- the amount of net consumption is 0 kWh.
If consumption and supply to the network are equal during the same metering period, both net consumption and net supply to the network are 0 kWh.
| Period (15 min) | Consumption | Supply to the network | Net consumption | Net supply to the network |
| Period 1 | 7 | 3 | 4 | 0 |
| Period 2 | 2 | 8 | 0 | 6 |
| Period 3 | 2 | 1 | 1 | 0 |
| Period 4 | 4 | 4 | 0 | 0 |
| Period 5-n | 9 | 5 | 4 | 0 |
| Total for all periods | 24 | 21 | 9 | 6 |
How does net metering data affect billing?
From 1 August 2026, network operators and sellers of electricity will use net metering data as the basis for preparing invoices.
The amount of net consumption is used on the network invoice as the basis for calculating:
- the network service charge;
- the renewable energy charge;
- the security of supply charge.
Electricity excise duty will continue to be calculated based on the total amount of electricity consumed.
Frequently Asked Questions
How is net metering data rectified?
Net metering data is rectified when the metering data for consumption or supply to the network changes. First, the consumption and supply-to-the-network data are rectified, and new net metering data is then calculated based on these values.
Do net quantities affect the calculation of usage capacity and monitoring of the use of a network connection?
No. The calculation of usage capacity and monitoring of the use of a network connection continue to be based on the quantities measured by the meter.
For which quantities is net metering data calculated?
Net metering data is calculated when the meter separately measures active energy consumption and supply to the network, ie when the meter is bidirectional. Net metering data is calculated only for active energy (kWh); net quantities are not calculated for reactive energy.
Which metering data is sent to the national data exchange platform?
For each 15-minute metering period, consumption and supply-to-the-network metering data are sent to the national data exchange platform as before. From 1 August 2026, net consumption and net supply-to-the-network data will also be sent in addition.
Do I need to do anything to enable net metering data?
No. If your place of consumption is equipped with a bidirectional meter, net metering data will be calculated automatically and uniformly for all customers with the relevant type of meter.