Portugal now requires grid-forming capability for large batteries — ahead of the EU
Since 23 October 2026, new large battery plants in Portugal must provide grid-forming capability and synthetic inertia. Opinion: a template other countries will copy.
What happened
A new Portuguese ordinance requires new battery plants connected to the transmission grid, or rated 45 MW or more, to provide grid-forming capability and synthetic inertia. Plants of 500 kW and up must switch automatically from charging to discharging when grid frequency drops. The rules took effect on 23 October 2026 for connection requests filed from that date, moving ahead of the EU's own revision of connection requirements. Source: Energy Storage News, 26 October 2026 (ess-news.com).
Our take
Portugal is the first, but it will not be the last. As inverter-based generation grows, more TSOs will demand grid-forming behaviour from batteries. For developers this is mostly a procurement question — grid-forming inverters exist and the cost premium is shrinking — but it belongs in your technical spec from day one, not as a change order after the connection agreement.
Check this on the Portugal map
Substations scored for BESS, solar, wind and data centers, plus land positions and instant site checks.
What to do with this
If you are developing in Portugal, check that your shortlisted equipment can meet the requirement before you file the connection request. Elsewhere in Europe, treat grid-forming as a likely future requirement and keep the option open in your contracts. Gridscouter's Portugal map ranks substations and shows what is already planned nearby. Every Gridscouter plan starts with 14 days of full access for €0 today. Cancel any time before the trial ends and you pay nothing.
Gridscouter scores are estimates from open map data, not grid operator capacity figures. Always confirm connection capacity with the grid operator.