Regulating Power

The pacemaker of our electricity grid

In an electrical energy supply system, supply and demand must always be in balance. However, as energy can only be stored to a limited extent, a mechanism is required that can compensate for unforeseen fluctuations and ensure the stability of the system. This is where the principle of regulating power comes in, which can also be described as the pacemaker of our electricity grid. 

What is regulating power?

Regulating power, also known as ancillary services, is the energy required by a grid operator to compensate for unforeseen power fluctuations in the electricity grid. It is used to maintain the balance between generation and consumption and to prevent system stability from being jeopardized.

Why do we need regulating power?

There have always been fluctuations in our electricity grid, particularly because electricity consumption cannot always be predicted perfectly. For example, our electricity grid cannot predict when someone will blow-dry their hair or start the next washing machine. With the increased expansion of renewable energies and variable electricity consumption profiles, fluctuations are also increasingly occurring on the generation side of the grid, as the wind does not always blow at the same strength and the sun does not shine continuously. Regulating power is therefore essential to compensate for sudden changes in electricity consumption or generation. It ensures grid reliability and prevents outages in the electricity grid. It also ensures that the frequency of the electricity grid remains stable at 50 Hertz, i.e., that the electricity changes direction 50 times per second, similar to a heartbeat. This is particularly essential for the safe operation of electrical devices. 

The different types of regulating power

There are three types of regulating power, where either electricity is taken from the grid or electricity is supplied to the grid and is thus available to the transmission system operators:

Frequency Containment Reserve (FCR): 

Rapid stabilisation of the power grid within 30 seconds.

Automatic Frequency Restoration Reserve (aFRR):

Must be available fully within five minutes.

Manual Frequency Restoration Reserve (mFRR):

Serves as a replacement for the automatic frequency restoration reserve and is activated for at least 15 minutes. 

How does the procurement of regulating power work?

The transmission system operators procure the required regulating capacity through transparent tenders on the ancillary services market. Power prices and availability payments play a role here, which the providers are compensated for in return for their willingness to provide the regulating power.

Who manages the use and provision of regulating power?

The transmission system operators are responsible for managing and activating the regulating capacity. They coordinate the use of the various types of regulating power and work closely together to ensure efficient utilisation of the available capacities.

Electricity storage as the key to grid stability

Electricity storage systems are playing an increasingly important role in the area of regulating power, particularly for FCR and aFRR. They make it possible to store surplus energy and release it again when required, turning electricity storage systems into flexible tools for stabilising the electricity grid.

Specifically, electricity storage systems have two important properties:

1. Fast response time:

Electricity storage systems can react to signals within milliseconds and either feed energy into the grid or draw energy from the grid. This makes them ideal for FCR, which requires rapid stabilisation of the grid in order to compensate for frequency fluctuations.

2. Provision of energy:

Electricity storage systems are also well suited for aFRR, which must be available within minutes. They can quickly provide part of their capacity or take it from the grid in order to balance the grid frequency within the required time frame, even in the long term.

Overall, electricity storage systems offer a flexible and effective solution to the challenges of regulating power by enabling a rapid response to fluctuations in the electricity grid and at the same time contributing to the integration of renewable energies. Their ability to store energy and release it when required makes them an important component of modern electricity supply and a necessary supporter of long-term system stability.

Conclusion

Regulating power is indispensable for the stability of our electricity grid. It makes it possible to react quickly to unforeseen fluctuations in electricity consumption and generation and thus ensure a continuous supply of electrical energy. The ancillary services market plays a decisive role in the procurement and remuneration of regulating power, while maintaining the frequency of the electricity grid is an essential function that is fulfilled by regulating power. Through their use in ancillary services and their flexible storage function, electricity storage systems therefore play an important role in our electricity system.