Glossary
aFRR (Automatic Frequency Restoration Reserve)
aFRR is a secondary regulation reserve of active power and frequency that automatically ensures a balance between electricity supply and demand during short-term deviations. The main goal is to maintain the frequency of the electricity system within the prescribed range (50 Hz ± 0.2 Hz).
How does aFRR work?
Automatic response: aFRR is automatically activated based on signals from the transmission system operator's control center (e.g., SEPS in Slovakia).
Activation time: It responds to deviations with an activation time of up to 5 minutes.
Supplementing primary regulation (FCR): aFRR builds upon primary regulation (FCR), which provides a fast response within 30 seconds.
Supporting tertiary reserve (mFRR): aFRR ensures frequency stabilization until the tertiary reserve (mFRR) is activated at 12.5 minutes.
aFRR is crucial for balancing deviations that occur, like those due to inaccurate planning of electricity production and consumption or sudden changes in the grid. The automatic and flexible response helps reduce risks associated with the loss of stability in the electricity system.
Aggregator of flexibility
A physical person or legal entity that combines, manages and represents several delivery points and/or production points in the electricity market. Aggregators of flexibility optimize the electricity consumption and production of their customers to efficiently respond to market demands and contribute to the stability of the power system.
These entities help balance fluctuations in energy demand and supply, leading to increased efficiency and reduced energy costs for all involved. Flexibility aggregators play a crucial role in the transition to sustainable energy with a higher share of renewable energy sources.
Alternator
An alternator is a device that converts mechanical energy into electrical energy in the form of alternating current (AC). This conversion process is crucial in various applications such as automotive systems, electric generators, and renewable energy sources.
Alternators are widely used in the automotive industry for charging batteries and powering vehicle electrical systems, as well as in power plants for generating electricity.