Grid balancing refers to the process of ensuring a real-time equilibrium between electricity generation and consumption. It is a critical task performed by the transmission system operator (TSO)—in Poland, this is Polskie Sieci Elektroenergetyczne (PSE)—aimed at maintaining the stability of the power system and keeping the system frequency at the nominal level (50 Hz in Europe).
Key Aspects of Grid Balancing:
Objective of Grid Balancing:
- Maintain continuity of electricity supply while preserving the system’s technical stability.
- Prevent overloading, power shortages, or excessively high frequencies.
Types of Balancing:
- Short-term balancing: Conducted in minutes or seconds, focusing on immediate responses to disturbances (e.g., using FCR, aFRR, or mFRR reserves).
- Medium- and long-term balancing: Involves forecasting supply and demand and planning the operation of power plants for upcoming days or weeks.
Balancing Tools:
- Balancing market: A market where generation units and consumers submit bids to supply or reduce energy as needed by the system.
- Power reserves: Mechanisms such as primary (FCR), secondary (aFRR), or tertiary (mFRR) reserves.
- Distributed energy resources: Integration of renewable energy sources (RES) and energy storage systems to support system flexibility.
- Demand-side response (DSR): Reducing energy consumption during peak hours or when supply is constrained.
Challenges in Grid Balancing:
- Variable generation from RES: Renewable sources like wind and solar are intermittent and require additional balancing actions.
- Increased distributed generation: Necessitates the integration of storage systems and local network management.
- Growing energy demand: Driven by expanding electrification, such as in transportation.
Role of the Transmission System Operator (TSO):
- Real-time monitoring of the grid's current state.
- Maintaining adequate reserves within the system.
- Long-term planning that accounts for supply and demand forecasts.
Technologies Supporting Balancing:
- SCADA (Supervisory Control and Data Acquisition) systems for network management.
- Automatic reserve regulation (AGC – Automatic Generation Control).
- Smart grids and advanced metering infrastructure (AMI).
Importance of Balancing:
Grid balancing is crucial for energy security and reliable electricity supply. With the increasing integration of variable renewable energy sources and changing demand patterns, this process requires advanced tools, flexibility, and collaboration among all market participants.
