德国电力系统中的灵活性技术和措施（英文版）-58页_1mb

Summary of Flexibility Technologies and Measures in the German Power System

Core Content

This report provides an overview of the flexibility technologies and measures in the German power system, focusing on how they support the transition to a renewable energy-based grid. Germany's goal of achieving climate neutrality by 2045 requires a significant increase in renewable energy (RE) production, which in turn necessitates a more flexible power system. The report outlines various flexibility options, including technical, demand-side, and market-related measures, and discusses their historical development and current implementation.

Main Flexibility Options

Technical Flexibility Options

• Conventional power plants: These, particularly coal and gas-fired plants, are currently the most important sources of flexibility. They provide dispatchable generation capacity and ancillary services, but their role is expected to decrease due to the phase-out of coal by 2038 and nuclear by 2022.

  • Flexibility parameters:
    • Minimum load (PMin): Lower values indicate higher flexibility.
    • Ramp rate: Higher rates allow for faster adjustments in power output.
    • Start-up time: Shorter times improve the plant's ability to respond to demand fluctuations.
  • Flexibility of coal and gas power plants is being enhanced through retrofits and new technologies.

• Biomass and biogas power plants: These are considered a key source of flexibility, especially with the introduction of a flexibility premium in the Renewable Energy Sources Act (EEG). Their potential for further flexibilisation is significant.

• Pumped-storage power plants: These are the second most important source of flexibility, offering reliable and large-scale storage capabilities.

• Batteries: Both large-scale and small-scale batteries are becoming increasingly important. Large-scale batteries are used for primary control energy and industrial applications, while small-scale batteries offer user-related flexibility in residential settings.

• Power-to-X (PtX): These technologies, which convert surplus electricity into other energy carriers, are not yet widely deployed in Germany. However, their potential is growing, especially with the development of the National Hydrogen Strategy and the implementation of 72 PtX pilot projects.

Demand-Side Flexibility (DSF) Options

• Industrial and commercial DSF: These sectors are expected to show increased flexibility in response to price signals on the wholesale market. DSF measures in this area are crucial for balancing supply and demand.

• Residential DSF: The introduction of smart meters and digital technologies is facilitating greater flexibility in private households. These technologies enable consumers to adjust their electricity usage based on price and availability.

System Operation Flexibility

• Redispatch and curtailment: These are measures used to manage grid bottlenecks. Since 2014, the volume and costs of redispatch and curtailment have increased significantly, indicating a growing need for system flexibility. The introduction of Redispatch 2.0 in 2021 allows for the inclusion of renewable energy and CHP plants as small as 100 kW in redispatch.

• Advanced forecasting of RE generation: Improved forecasting methods help reduce the uncertainty of RE feed-in, thereby decreasing the need for system flexibility.

• Higher utilisation of the existing grid: Optimising the use of existing infrastructure can reduce the need for new grid expansion and lower system costs.

• Cooperation between DSOs and TSOs: Enhanced coordination between distribution and transmission system operators is essential for managing the increased variability of RE generation.

• Cooperation and coordination between TSOs: This ensures more efficient system operation and better integration of flexibility measures across the grid.

• Cross-border power exchange: This helps balance supply and demand across Germany and its neighbors, contributing to system flexibility.

Market Design Flexibility

• Increasing granularity in the power market: This allows for more precise and flexible market mechanisms, enabling better integration of variable RE.

• Ancillary services: These are essential for maintaining grid stability and include frequency control, voltage control, and reserve capacity.

• Support schemes: These include grid charges and incentives for flexibility, which are critical for promoting the adoption of flexible technologies and practices.

Key Information

• Legal and institutional context: The report is published by the German Energy Agency (dena) as part of the Sino-German Energy Transition Project, supported by the German Federal Ministry for Economic Affairs and Climate Action (BMWK) and the National Energy Administration (NEA) in China.

• Regulatory milestones:

  • 2005: Adoption of the Ordinance on Electricity Grid Tariffs.
  • 2008: Establishment of EPEX SPOT with 1-hour auctions.
  • 2009: Introduction of direct marketing of RE under the Renewable Energy Sources Act (EEG).
  • 2011: Decision to phase out nuclear power by 2022.
  • 2012: Introduction of a flexibility premium for biogas power plants.
  • 2016: Adoption of the Electricity Market Law (Strommarktgesetz) and the Law on the Digitalisation of the Energy Transition.
  • 2017: Introduction of smart metering systems and changes in primary control energy procurement.
  • 2020: Decision to phase out coal by 2038 and reduction of primary control energy auctions to 4-hour periods.
  • 2021: Implementation of Redispatch 2.0, allowing participation of small RE and CHP plants in redispatch.

• Flexibility challenges: As the share of variable RE increases, the residual load becomes more volatile, requiring more frequent and effective flexibility measures. The report highlights the need for regulatory and market reforms to support this transition.

• Economic and environmental impact: Redispatch and curtailment have led to economic waste and environmental concerns, underscoring the importance of developing alternative flexibility solutions such as grid expansion and smart technologies.

• Future outlook: The multi-use approach, combining grid-serving and market-related functions, is seen as a more economically effective solution for increasing system flexibility. Continued technological development and policy support are necessary to achieve climate neutrality.

Conclusion

Germany's power system is evolving to meet the challenges of a high renewable energy share, with a strong emphasis on flexibility. A combination of technical, demand-side, and market-related measures is essential to ensure grid stability, reduce costs, and support the transition to a low-carbon energy system. The report serves as a valuable reference for policy development and international cooperation in the energy transition.