Redispatch means that the transmission system operator (TSO) request to adjust the active power feed-in from power plants to avoid or resolve occuring congestion. This measure can be implemented both within the grid area and between different grid areas. By lowering the active power feed-in of one or more power plants while at the same time increasing the active power feed-in of one or more other power plants, the total active power feed-in remains virtually unchanged, but the congestion is removed.
The need for redispatch is determined through complex grid calculations. Many factors interact, such as line interruptions for maintenance purposes, incidents that could not be calculated, weather conditions and their impact on the generation of renewable energy.
Through extensive analyses in the scope of congestion management, imminent bottlenecks are determined on time in the European context and countermeasures are organised to ensure that at all times and at each point of the grid, available and consumed energy are balanced and can be transported without congestion. Otherwise, there is a danger of power outages.
The transmission system operator therefore bears great responsibility for the success of the energy transition. Based on continuous grid analyses, measures are identified to guarantee system security, such as the need for reserve power plant capacity and redispatch.
More information on congestion management can be found here.