Portugal has expanded the participation of renewable energy in electricity system balancing services after authorising 1,668 MW of solar and wind capacity to participate in the Manually Activated Frequency Restoration Reserve (mFRR) market and 340 MW to provide Secondary Control Band (aFRR) services. The milestone marks a further step in integrating renewable resources into the operation of the country's National Electricity System (SEN).

According to REN – Redes Energéticas Nacionais, ancillary services are essential to maintaining the real-time balance between electricity generation and consumption. While secondary control (aFRR) automatically corrects frequency deviations, the mFRR market is activated manually by system operators to restore system balance or replenish reserve capacity when additional support is required, helping ensure the reliability and security of electricity supply.

The newly authorised capacity includes solar and wind generation as well as battery energy storage systems, broadening the range of resources available to deliver these services. REN said the increased participation of renewable and storage assets will contribute to more efficient operation of the National Electricity System while supporting greater integration of variable renewable energy.

The transmission system operator also highlighted that solar, wind and battery storage are playing an increasingly important role beyond electricity generation by providing essential grid-balancing services that enhance system flexibility, stability and security. Expanding the pool of authorised resources is expected to improve the efficiency of system operation as Portugal continues increasing the share of renewable energy in its electricity mix.

According to REN, the latest milestone reflects the ongoing modernisation of Portugal's electricity system and its adaptation to a power system with a growing penetration of renewable energy, while maintaining high standards of operational reliability and security.