How should you read your electricity invoice if you are a prosumer?
Reading your electricity invoice as a prosumer can be a challenge, especially if you are just starting out with solar PV. This post will help you understand the key elements of the invoice and what they mean for your household budget.
Prosumer contract and electricity invoices for photovoltaics
The installation of a photovoltaic system brings many benefits. It allows us to enjoy environmentally friendly and cheap electricity. However, the downside is that in Poland, electricity production is distributed unevenly throughout the year. For this reason, a form of billing known as prosumer has been developed.
Prosumer is the term for the owner of a photovoltaic installation. It is a combination of the words producer and consumer. More precisely, it means a person who produces electricity and at the same time uses the electricity grid. The prosumer 'stores' the electricity generated during the uplift on the operator's grid and can use it during the period of reduced production.
How do I read my electricity invoice and what items are on it?
To begin with, not every prosumer what exactly all the items on the electricity invoice mean. If you want to find out what is on your electricity invoice without a photovoltaic installation, please see our post - What does the electricity bill consist of? https://sollab.pl/z-czego-sklada-sie-rachunek-za-prad/. In the case of prosumers, several new items appear on the factor, such as:
- Sum of hourly positive balances The amount of energy that you have taken from the grid in a given billing period. This quantity is determined in accordance with the summed energy balancing mechanism set out in the RES Act. This balancing takes place every hour of the day and consists of settling the difference between the amount of energy taken from the grid in relation to the amount of energy injected into the grid.
- Sum of hourly negative balances The amount of energy that you have fed into the grid in a given settlement period. This quantity is determined in accordance with the summed energy balancing mechanism set out in the RES Act. This balancing takes place every hour of the day and consists in settling the difference between the amount of energy taken from the grid in relation to the amount of energy injected into the grid
- amount of energy consumed - indicates the value of power consumption, which was higher than production;
- the amount of energy produced - surplus electricity that could not be used for current needs and was sent to the operator;
- amount of energy billed at a discount - the amount of electricity that has been taken by the utility for the service. For networks up to 10 kWp, this is equivalent to 20%, and for larger networks 30% of all energy transmitted;
- surplus energy - the difference between the amount of electricity produced and the amount collected for the benefit of the power company
Prosumer billing and surplus electricity
The electricity generated by photovoltaic panels can be used immediately. In some situations, particularly in summer when the sunshine is higher, energy production can exceed demand. The excess energy generated by the photovoltaic installation can be sent to the grid and used at times when production is lower, such as in winter.
It is worth knowing that the settlement of energy from storage takes place in subsequent billing periods, and the surplus can be used within a maximum of 365 days from the date of reading - after that, it is forfeited. In addition, due to the quantity factor introduced under the RES Act, it is only possible to recover part of the electricity discharged into the grid. For photovoltaic installations up to 10 kW, 0.8 kWh can be recovered from 1 kWh of transmitted energy, while for installations above 10 kW it will be 0.7 kWh (the rest is retained by the electricity company).