The allegations centre on the signals grid operators send to select companies qualified to provide balancing energy. Such energy keeps power lines stable by ironing out sudden deviations between supply and demand. This can happen when a power plant fails, or when solar or wind veers abruptly from forecasts. Few companies can provide balancing energy because they need to respond to requests for large volumes of electricity within seconds or minutes.

Grid operators’ signals to activate balancing energy are not publicly disclosed in real-time in Germany. Nor is the state of imbalance on the grid. Yet…