MADRID, Dec 23 (Reuters) - Spain's competition watchdog has approved rules setting the financial return for power grid activities at 6.58% for the next six years, saying it sought to balance network investment needs with consumer protection.

The massive blackout that hit Spain and Portugal on April 28 reignited debate about investment in the country's power networks and the return on such investments. Power companies invest in grids in exchange for a stable return, with consumers ultimately paying that guaranteed rate through their electricity bills.

Sign up here.

In a statement late on Monday, the CNMC watchdog said that the new financial remuneration rate for electricity transmission, system operation and distribution would rise by 100 basis points for 2026 to 2031 from 5.58% in the previous six-year period.

The watchdog also introduced guidelines to calculate the remuneration for electricity distribution, aiming to improve network efficiency and quality, reduce losses and provide incentives for electrification.

The distribution methodology aligns with government investment limits by remunerating audited investments up to 0.13% of gross domestic product, the CNMC said.

The regulator said it followed a "guarantee-based and participatory" process in its decision, including seven public consultations and five public hearings, and sought the view of Spain's energy ministry on five occasions.

Energy groups such as Iberdrola (IBE.MC) , opens new tab and Enel (ENEI.MI) , opens new tab have increased their focus on expanding and upgrading power grids in recent years while taking a more selective approach to renewable energy projects.

https://www.reuters.com/business/energy/spanish-regulator-sets-658-return-power-grids-2026-2031-2025-12-23/