A lack of electricity strained the German power grid at several moments in June, power transmission grid operators (TSO) said in a statement.

“The situation was very tense and could only be managed with the support of European partners,” the operators said in a written statement. As too little power was available to meet demand, the grid frequency fell “throughout the European integrated grid”, and the four TSOs had to arrange for additional “control power” to balance out generation and demand, they said.

Jan Aengenvoort, spokesperson for virtual power plant Next Kraftwerke, told Clean Energy Wire that the reason for the shortfall could lie in regulatory deficiencies, which have led to traders taking advantage of the system. However, the Federal Network Agency (BNetzA) cautioned that the cause was “not yet clearly established”. Grid operators will need several weeks to analyse the situation and determine the cause, they said.

Next Kraftwerke has long criticised new market regulations. The federal network agency is examining a reform proposal by grid operators.

Activating control power is comparatively expensive and traders try to avoid it by forecasting supply and demand as exactly as possible.

Due to a 2018 regulation, however, activating control power can be less costly than trying to sell or buy necessary amounts on regular markets, said energy expert Claudia Kemfert, head of the department of Energy, Transportation, Environment at the German Institute of Economic Research (DIW Berlin). This decreases the incentive for traders to ensure a balance of demand and supply, she said.