Portugal opened two auctions on 23 October 2026 to allocate grid connection capacity: 750 megavolt-amperes (MVA) for standalone batteries and 300 MVA for renewable plants with co-located storage. Portugal sells grid capacity in MVA, and the rules require a battery’s installed power to be at least the capacity awarded, so for practical purposes 1 MVA here means 1 MW of battery. These awards give developers the right to connect their projects to the electricity network. The final rules improve on the draft put to consultation in July, but the connection arrangements and time needed to build them will also shape the value of each location.

Key takeaways

• Of the 1,800 MVA offered for standalone batteries, 1,000 MVA is in lots with a direct-connection option. Projects in the other 800 MVA can only connect through a line shared with other plants, under a combined capacity cap and a sharing agreement.
• Panóias, a new REN substation in the southern Alentejo, offers 400 MVA through a direct connection, equivalent to 53% of the capacity the standalone auction will award.
• REN can restrict a standalone battery’s charging or discharging to relieve grid congestion for up to 500 full-power hours a year, down from 750. In the worst case, that annual allowance costs a four-hour battery 15% of its day-ahead trading revenue.

Connection arrangements vary by location

The standalone auction covers 13 substations operated by REN, Portugal’s transmission system operator. These substations are the points where projects will connect to the high-voltage network. All the connections are at 400 kV, and most of the locations are in southern Portugal.

However, a place in the auction does not necessarily come with a separate connection. Eight of the substations have no spare connection bay, the equipment and space within a substation needed to connect a circuit. Batteries at these locations must therefore share a line with other grid users. Where that shared connection is a single line, all the plants using it can together inject no more than 420 MVA and charge no more than 400 MVA.

Developers must also agree how to share the line with its other users. To allow time for this, up to 12 months of diligent negotiation can be excluded from their project delivery deadlines.

The auction groups connection capacity into nine lots, each associated with one or more substations. Four lots, totalling 800 MVA, offer only shared-line connections. The remaining 1,000 MVA is in lots with a direct-connection option, including at the Estremoz and Alcochete substations. The largest such opportunity is Panóias, which offers 400 MVA in a single lot.

Developers must also consider whether the substation will be ready when their battery is built. The Vale Pereiro substation is still under construction, although it is not expected to add delay unless litigation or an administrative decision suspends the works. The timetable for the Abrantes substation depends on its remaining approvals: connection cannot take place until at least 24 months after its final licence or public-utility declaration.

Portugal will award less than half the capacity offered

The capacity listed at these locations exceeds the amount Portugal intends to award. The standalone auction offers developers a choice of 1,800 MVA across nine lots, but only 750 MVA will be allocated. Similarly, the co-located auction offers 800 MVA across three lots for a total award of 300 MVA.