Keeping Portugal's Grid in Balance Now Costs Four Times as Much as in 2023, and Part of the Bill Moves Into a Charge Every Consumer Pays

The cost of keeping Portugal's electricity system stable has roughly quadrupled since 2023, and part of it is now moving out of retailers' prices and into a regulated tariff that every consumer pays. Expresso reported on Thursday that the cost had risen 320 percent; the figures come from the Entidade Reguladora dos Serviços Energéticos (ERSE, the energy regulator), which approved new rules on 14 October.

What these charges are

ERSE calls them encargos de regulação do sistema (system regulation charges). They pay for the work REN, as manager of the national grid, does in real time to keep supply and demand in balance and the network safe: holding reserve capacity to restore the frequency, and resolving "technical restrictions", for example ordering a gas-fired power station to start up because a line is overloaded or a region lacks firm generation.

REN bills the charges to electricity retailers and large buyers. Retailers then pass them on, either inside the price per kilowatt-hour or explicitly through an indexed formula, depending on the contract.

How much they have grown

According to ERSE's consultation document, built on REN market data, the charges averaged:

• 4.88 euros a megawatt-hour in 2023;
• 7.99 euros in 2024, up about 64 percent;
• 13.18 euros in 2025, up about 65 percent;
• 20.26 euros from January to May 2026, peaking near 28.90 euros in February.

The 2026 average is about 315 percent above 2023. In total the charges came to 410.5 million euros in 2024, 692.8 million in 2025 and 458.8 million in the first five months of 2026. Their weight in the cost of energy bought on the wholesale market went from about 5.2 percent in 2023 to 16.6 percent in 2025 and more than 25 percent this year, even leaving out February.

ERSE gives three reasons. From late summer 2024 REN began calling on gas plants as backup for a grid increasingly run on wind and solar power, which cannot be dispatched on demand. After the Iberian blackout of 28 April 2025, REN added further measures to run the system with reinforced security. Then Storm Kristin, from 28 January 2026, damaged transmission lines in the Centre region. ERSE describes the rise as a structural trend, although it notes that the charges have eased since the February peak.

What changes for bills

Under Regulamento n.º 3/2026 and Diretiva n.º 5/2026, a share of these costs moves into the Uso Global do Sistema (global use of the system) tariff, part of the network access charges on every electricity bill, whatever the supplier. The share is 40 percent of the cost of resolving technical restrictions, phased in from 25 percent of the estimated amount in the last quarter of 2026. ERSE's consultation report says the change takes effect from 15 October; the regulation itself enters into force the day after it appears in the Diário da República (official gazette). It will be charged partly per kilowatt-hour and partly on contracted power, and ERSE will set the share and the cost types each year.

For most households these costs were already in the price; the change spreads part of them across all consumers through a regulated charge rather than leaving it to each retailer. ERSE has not published an estimate of the effect on a typical household bill.

What comes next

ERSE will also create a reserve-capacity lot for firm generation or storage, so REN can contract backup in advance rather than through costlier last-minute calls, and a forward hedging product traded on OMIP, the Iberian derivatives exchange. A REN pilot of probabilistic grid-planning tools will follow later. The regulator says the package should help stabilise final electricity costs. Wholesale prices are already high this autumn, as we reported on 10 October, and ERSE's latest report put the blackout's cost to customers at about 10 hours without power.