Grid operator calls for more careful expansion of photovoltaics in Germany

German transmission grid operator 50Hertz has called for a more balanced and careful approach when it comes to the further expansion of solar photovoltaics (PV), saying there is a risk of overloading electricity transmission networks if complementing measures are not carried out properly. At a press conference in Berlin on Monday (10 March), the CEO of 50Hertz, Stefan Kapferer, highlighted “a growing number of difficulties in terms of affordability and system stability. That is why the further growth in the photovoltaic segment in particular should be guided by more realistic assumptions about the expected electricity consumption, by the development of grid infrastructure and by increased storage capacities to support the grid.”

Kapferer stressed the necessity of quickly adjusting conditions for renewable energy feed-in and power plant capacities, including the construction of new power plants at locations that support the grid throughout Germany.

“We furthermore require a paradigm shift if the share of renewable energy keeps growing: the principle of 'as much as possible, as quickly as possible and completely uncontrolled’ needs to be replaced by the principle of grid support. The current approach to promote renewable energy rewards the highest possible electricity feed-in. In the future, targeted incentives should be established for development as well as scheduling in support of the grid.”

50Hertz said installed PV capacity – which covers around 15 percent of total electricity demand – increased by almost 4 gigawatts (GW) last year. This contributed to situtations arising with negative electricity prices, particularly on sunny days with high solar feed-in and low overall power consumption. By contrast, the lack of adjustable power plant capacity also led to extremely high prices when there was minimal solar and wind power, so-called Dunkelflaute (dark doldrums) periods.

“Until now, both solar power peaks and dark doldrums could be handled well without putting system stability or the security of supply at risk,” Kapferer said. “However, the large upward and downward price fluctuations are a clear warning signal from the electricity market.”

Kapferer welcomed a new joint document issued by the conservative CDU/CSU alliance and the Social Democrats (SPD), which are set to form Germany’s next government, business daily Handelsblatt reported. The paper also envisages the construction of up to 20 GW of gas-fired power plant capacity by 2030.