The four transmission network operators are 50 Hertz, Amprion, TenneT and TransnetBW.

The EEG levy, which added on top of end consumers' electricity bill in Germany, would be increased to 6.756 euro cents (0.074 U.S. dollars) per kilowatt hour (kWh) of electricity in 2020. Currently, the EEG levy is amounting to 6.405 euro cents per kWh.

One of the reasons for the EEG levy to rise was the development of the overall "account balance" of Germany's renewable energy transition, according to the four operators.

Although the balance of the EEG had recorded a surplus of 2.2 billion euros at the end of September, the account balance had been 40 percent lower than in the previous year, which "led to a rise" in the EEG levy for 2020, they said.

The German government is planning to reduce the EEG levy by 0.25 euro cents per kWh in 2021, according to a governmental climate action plan.

Reductions to the German EEG levy would be financed with the "income from the planned national CO2 pricing," Ralf Wissen, managing partner at r2b energy consulting, told Xinhua.

The development of the EEG levy in the coming years would "depend largely on wholesale electricity prices", because EEG subsidies paid to operators of renewable energy plants in Germany were "unlikely to change much," Wissen said.

Besides the EEG levy, charges for the use of electricity grids in Germany are expected to increase as well in 2020. According to the German price comparison company Check24, the usage fees for electricity networks would increase by around 9 percent next year.