BSW Solar gives the all-clear

19.01.2025

Source: E & M powernews

The industry association BSW Solar denies media reports about an increased risk of blackouts when there is a lot of sunshine. The risk of a power grid overload is very low.

"The flood of electricity could be too great at Easter" or "Could there be power cuts on public holidays?". Various media outlets have recently reported in these and similar terms on the potential risk of blackouts due to excessive solar feed-in to the power grid. The German Solar Industry Association (BSW Solar) considers the reports to be exaggerated.

According to the association, the risk of overloading the electricity grids, a temporary overload in balancing or even a blackout as a result of too much solar power is very low, BSW Solar announced on February 18. Even in the unlikely event that it is not possible to balance electricity supply and demand in time, the consequences should remain manageable and controllable according to energy experts, the association continued.

The association goes on to say that claims that an increase in frequency to over 50.2 Hertz would only result in an inadequate emergency mechanism for PV inverters, threatening abrupt mass shutdowns of PV systems and a drastic drop in grid frequency, are incorrect. "The statement that sudden and massive frequency fluctuations can occur again when the photovoltaic systems are switched back on is just as false," said Carsten Körnig, Managing Director of BSW Solar.

Latest solar peak law clarifies existing rules

"Since 2012, photovoltaic systems in Germany have not simply been switched off when frequency peaks occur," Prof. Bernd Engel, grid integration expert at the Elenia Institute at TU Braunschweig, is quoted as saying in the association's press release. Instead, the power is continuously throttled by the inverters depending on the grid frequency. Engel: "The higher the frequency increases, the more the inverter reduces its feed-in power." This is precisely regulated by the application rules of the German Association for Electrical, Electronic & Information Technologies. These requirements apply without exception to all photovoltaic systems and battery storage systems. In addition, all photovoltaic systems with an output of more than ten kilowatts that were put into operation before 2012 were retrofitted in accordance with the provisions of the System Stability Ordinance, which came into force in July 2012.

According to the scientist, the supposed risk of a "rebound effect", i.e. frequency fluctuations triggered by the restart of solar systems, is also ruled out in practice. If the frequency drops again, the solar systems increase their output in the same way. Even if some inverters switch off completely, the grid must first be in a stable state for at least one minute before the inverters switch back on and slowly start up again at ten percent nominal power per minute in order to prevent this "rebound effect".

According to BSW Solar, the recently adopted new regulations in the Solar Peak Act have also further specified the requirements for controlling solar systems. The distribution grid operators were also obliged to regularly check the controllability of photovoltaic systems in future.

Author: Heidi Roider