Transmission grids are central to the energy supply of the future
Transmission grids ensure secure power supply. They continuously balance generation and consumption, since electricity cannot be stored in the grid. Transmission grids can transport renewable energy over long distances and thus partially compensate for volatile generation. The increasing share of renewable energy has changed the job of transmission grids. They will continue to be an important part of the energy system of the future because they:
- transport electricity from renewable energy sources to where it is needed,
- connect northern and southern Germany and enable a common energy market with neighbouring countries,
- bring wind power inland from offshore plants, including to North Rhine-Westphalia, and
- ensure grid quality, stability and supply security by efficiently using various system services in the interconnected system, such as black start capability and short circuit power.
Grid stability despite volatile renewable energy sources
Transmission system operators already have to make increased efforts to ensure grid stability in the age of renewable energy. As part of grid congestion management, grid operators take a variety of stabilising measures such as redispatch and feed-in management.
In redispatch, which was used until September 2021, transmission system operators directed large, conventional power plants with an installed capacity of at least ten megawatts to shift planned power generation between different power plants in order to prevent grid bottlenecks. The enhanced Redispatch 2.0 now in force affects plants with an installed capacity of 100 kilowatts or more, including renewable energy sources and CHP plants. In addition to transmission grid operators, distribution system operators can now also direct the redispatch.
Several solutions already exist to reduce grid congestion management measures while maintaining grid stability:
- Demand-driven grid expansion
- Increased expansion of storage facilities
- Holistic view of energy and linking the heat, industry and transport sectors (sector coupling)
- Flexible design of power demand in terms of demand-side management