The term "redispatch" describes the process by which the transmission system operator (TSO) changes the power allocations of power plants at short notice in the event of grid bottlenecks or other unforeseen events in order to maintain the balance between electricity generation and consumption in the grid and avoid bottlenecks. An increase in feed-in to the grid corresponds to positive redispatch, a reduction is called negative redispatch. For negative redispatch, the grid operators purchase part of the production obligation from power plant operators and instead commission operators on the opposite side of the bottleneck. In the event of an impending bottleneck, power plants immediately upstream of the bottleneck are instructed to reduce their electricity feed-in to the grid, while power plants downstream of the bottleneck must increase their feed-in accordingly. This creates a load flow that counteracts the congestion.
Redispatch can be used within a control area as well as across control areas and is only carried out by power plants with a capacity of more than 10 MW.
In Germany, redispatch is regulated by law through Section 13 of the Energy Industry Act (EnWG) and the Electricity Grid Access Ordinance (StromNZV). The EnWG regulates the general framework for the operation of energy supply networks and network access, while the StromNZV sets out the specific requirements for network access and network connection conditions.
Within the framework of these statutory provisions, the Federal Network Agency, as the regulatory authority for the electricity and gas markets in Germany, has issued further regulations that specify the redispatch process in more detail. These include, for example, the Redispatch Ordinance (Redispatch 2.0), which has been in force since October 1, 2021 and specifies the requirements for implementing the redispatch process.
The new Grid Expansion Acceleration Act (NABEG) that came into force also defined new requirements for measures to prevent or manage grid bottlenecks. Redispatch 2.0 was introduced on October 1, 2021. Paragraphs 13a and 14 were added to the EnWG for this purpose. Specifically, Redispatch 2.0 now stipulates that all generation plants with a capacity of 100 kW or more can be used for redispatch. This also includes all renewable energy generation plants as well as energy storage and CHP plants, which were previously excluded.
Redispatch 2.0 is intended to improve the grid integration of renewable energies. By increasing the size of the plant pool across the board, greater efficiency can also be achieved compared to previous procedures. The aim is also to reduce the costs for redispatch and grid connection management, which have risen steadily in recent years, and to eliminate grid bottlenecks without discrimination.
In Redispatch 2.0 measures, renewable energy systems are only used when the possibilities of conventional energy sources have been exhausted or the costs for eliminating bottlenecks are 10 times lower or 5 times lower than for combined heat and power generation. This system is compensated in Redispatch 2.0. However, grid operators only pay a standard market premium.
In Germany, the remuneration for positive redispatch is cost-based and, according to Section 13a of the Energy Industry Act (EnWG), should put the plant operator in an "economically neither better nor worse position" after the measure has been implemented. Changes to the redispatch procedure are regularly discussed. Since no profit is envisaged from redispatch, there is also little incentive for plant operators to participate in redispatch measures.
In general, the compensation for redispatch measures that contribute to relieving the power grid is lower than for measures that lead to an increase in generation capacity. The costs of redispatch are ultimately passed on to electricity customers and levied as part of the network charges.
The cost of redispatch can be significant depending on the scope and duration of the deployment. In recent years, there has been a continuous increase in both the scope and the cost of redispatch. In 2021, the cost of redispatch in Germany was approximately €590 million. In comparison, the cost volume in the previous year was 240 million euros and recorded a more than 100 percent increase within one year.
There are many reasons for the increase in redispatch costs. On the one hand, the feed-in of renewable energies, especially wind and solar energy, is increasing, which leads to higher volatility in the power grid and makes the use of redispatch necessary more frequently. On the other hand, the power grids in many regions of Germany are not yet sufficiently developed to accommodate the increasing feed-in of renewable energies.
The majority of redispatch measures were carried out due to electricity and attributed to the cause of occurring grid bottlenecks.
It can be assumed that the costs for redispatch will continue to rise in the future as long as the expansion of the power grids does not keep pace with the increasing feed-in of renewable energies.
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