Secondary Control Reserve (aFRR) with Battery Storage

Secondary control reserve is an important component of grid stabilisation in the electricity system. It balances out frequency deviations that remain after the initial response from primary control reserve.

How secondary control reserve works

Secondary control reserve is activated automatically within a few minutes. It ensures that the balance between electricity generation and consumption is restored and that the grid frequency remains stable.

The role of battery storage

A large battery storage system can take on this task efficiently. As a grid-scale storage system, it flexibly provides or absorbs energy in order to balance out fluctuations in the electricity grid.

This relieves conventional power plants and at the same time improves the integration of renewable energies.

Distinction from primary control reserve

While primary control reserve responds within seconds, secondary control reserve takes over stabilisation over a longer period of several minutes.

Together, both mechanisms ensure a stable and secure electricity supply.

Frequently Asked Questions (FAQs)

What is secondary control reserve?

Secondary control reserve is a form of grid stabilisation that automatically balances out frequency deviations in the electricity grid over a period of minutes.

How quickly does secondary control reserve respond?

Secondary control reserve is activated within a few minutes and stabilises the electricity grid after primary control reserve.

What role does battery storage play in secondary control reserve?

Battery storage systems can flexibly provide or absorb energy and are therefore well suited to balancing out grid fluctuations over several minutes.

How does secondary control reserve differ from primary control reserve?

Primary control reserve responds within seconds, whereas secondary control reserve stabilises the grid subsequently over a period of minutes.

Why are large battery storage systems important for secondary control reserve?

Large battery storage systems can provide energy quickly and flexibly and help to relieve conventional power plants and better integrate renewable energies.