Portugal Mandates Grid-Forming for Large Battery Storage Plants

Portugal has introduced new regulations mandating grid-forming capabilities for significant battery storage installations. Effective since October 23, these rules apply to new connection requests for the transmission grid and to plants rated at 45 MW or more. The objective is to enhance grid stability and facilitate the anticipated growth of energy storage.

Under the new ordinance, plants of 500 kW or more must automatically switch from charging to discharging when the grid frequency drops. The grid-forming obligation also extends to plants connected at 110 kV or above, with specific terms to be set by grid operators. For installations between 10 MW and 45 MW, this requirement is linked to provisions within grid capacity titles, permits, or tender documents. Smaller plants are only required to provide this capability if explicitly mandated in such documentation.

The technical parameters are based on a joint report by European transmission and distribution operator bodies, industry associations, and standards organizations. For frequency deviations occurring within the range of 47.0 Hz to 52.5 Hz, as well as during swift changes in frequency, battery storage facilities are required to hold extra power and energy to supply synthetic inertia. The mechanical starting time for inertia emulation must be adjustable from 1 to 20 seconds, with a default of 12 seconds. Furthermore, a damping ratio of at least 10% is required for power oscillations between 0.1 Hz and 10 Hz.

All plants of 1 MW or more must be technically capable of providing frequency containment and restoration reserves, as well as voltage and reactive power control. A default underfrequency relay setting of 49.2 Hz during charging mandates an automatic switch to discharging. Load changes outside reserve activation must be ramped over a ten-minute period unless otherwise instructed by the system operator. Plants above 1 MW are required to provide real-time monitoring and remote control to the system operator.

The Portuguese government has established these requirements now, anticipating the revision of the EU generator connection code. This aligns with Portugal's national storage strategy, which targets 6.9 GW of storage capacity by 2030, and with funding calls under the EU-backed recovery plan, collectively covering over 1 GW of projects. The government has also planned an auction for 750 MVA of battery storage capacity. Although Portugal's current battery fleet is modest (20 MW at the end of 2025), accelerated deployment is expected, partly due to €100 million awarded to projects totaling approximately 500 MW.

Source: pv magazine.

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• Portugal
• batterijopslag
• BESS
• netstabiliteit
• grid-forming
• regelgeving
• energieopslag

This article is an Oranje-Eco summary of a report by pv magazine. Read the original: pv magazine.