aFRR

aFRR (automatic Frequency Restoration Reserve) is a system-level balancing service operated by MAVIR (the Hungarian transmission system operator), which ensures the automatic restoration of grid frequency. Since May 2, 2022, aFRR capability and MAVIR accreditation have been a condition for connecting every weather-dependent generator above 50 kVA (solar).

In practice, this means that MAVIR can automatically curtail the generator — for which compensation is paid. Generators below 5 MW can participate only through an aggregator: the aggregator signs the contract, builds the IEC-104 communication and handles the accreditation.

At the same time, aFRR-accredited battery storage can also be a source of revenue on the balancing market — so the obligation can be turned into a business opportunity.