Congestion management refers to all measures taken by grid operators to detect, avoid, or eliminate overloads in the power grid. Due to the increasing expansion of renewable energies, the decentralization of generation, and rising flexibility requirements, congestion management in the power grid is becoming increasingly important. It is a central element for a secure, stable, and efficient grid operation.
Definition of terms
Congestion management includes grid-side and market-based interventions that serve to prevent overloading of lines or grid components. A grid bottleneck occurs when the available transport capacity of a grid element is not sufficient to safely transmit the planned power flows.
The goal of congestion management is to ensure security of supply and grid stability at all times.
Causes of grid bottlenecks
Grid bottlenecks can arise for various reasons, including:
- high simultaneous feed-in of renewable energies
- regional imbalances between generation and consumption
- limited grid capacities
- delayed grid expansion
- unplanned equipment failures
In particular, the spatial separation of power generation and power consumption increases the demands on congestion management.
Forms of congestion management in the power grid
Congestion management can take place at various levels:
- preventively through forward-looking grid planning
- operationally through short-term interventions
- structurally through grid expansion and grid optimization
Both technical measures and market-based instruments are used.
Technical and operational measures
The central measures of congestion management include:
- Adjustment of feed-in power
- Control of battery storage systems
- Activation of flexible consumers
- Grid switching
- Use of automated control systems
- Use of Phase Shifting Transformers (PSTs) for targeted control of power flows in the transmission grid
In practice, congestion management is often implemented through procedures such as Redispatch 2.0, in which plants are specifically ramped up or down.
Role of grid operators
Grid operators are responsible for the implementation of congestion management. This includes:
- Forecast of grid loads
- Identification of critical grid states
- Arrangement and coordination of measures
Both distribution grid operators and transmission grid operators & control zones work closely together to control bottlenecks across grids.
Relationship with market mechanisms
Congestion management intervenes in situations where market-based processes alone are not sufficient. Electricity markets such as the Day-Ahead Market & Spot Market or the EPEX Spot Intraday Market do reflect supply and demand, but do not automatically take local grid restrictions into account.
Therefore, congestion management complements market mechanisms such as the merit order principle with grid-technical control.
Relevance for companies
Companies are affected by congestion management if they:
- operate their own generation plants
- use battery storage
- use controllable loads
In such cases, feed-in or consumption can be adjusted temporarily. At the same time, the demands on transparency, forecast quality, and technical controllability increase, for example through Energy Management Systems (EMS) and Energy Monitoring & KPIs (EnPI).
Importance of flexibility and storage
Flexibility is a central lever in congestion management. Energy storage and controllable loads enable:
- local relief of grids
- temporal shifting of power flows
- reduction of grid-side interventions
Therefore, there is a close relationship between congestion management and:
- Grid-supportive storage control
- Load shifting through storage
- Demand Side Management (DSM)
- Decentralized grid control with AI
Distinction from related terms
Not to be confused with:
- Control energy: short-term compensation of frequency deviations
- Secondary control power (SRL) and Tertiary control power (TRL): Sub-areas of control energy
- Grid fees and levies: Cost components of electricity supply
- Capacity market vs. energy market: market instruments for security of supply
Summary
Congestion management in the power grid includes all measures to avoid and eliminate grid overloads and is a central instrument for ensuring security of supply. Causes of bottlenecks are mainly decentralized power generation, regional imbalances, and limited grid capacities. Grid operators use both technical and market-based measures, with procedures such as Redispatch 2.0 playing a central role. For companies with generation plants, storage, or flexible consumers, congestion management is becoming increasingly relevant, as flexibility and digital control can make an important contribution to local grid stabilization.
Note: Please note that this wiki entry on intensive grid use is for informational purposes only and does not constitute legal advice. be.storaged GmbH assumes no guarantee for the completeness, accuracy and timeliness of the information in this entry.
