Fuel prices for island generators: settlements 2nd half 2025

Key data

Operators of electric power plants in Spanish non-peninsular territories can now know the reference prices that will be used to calculate what they will receive—or adjust—in the settlements for the second half of 2025. The Resolution of 8 May 2026 from the General Directorate of Energy Policy and Mines sets the fuel prices at port applicable to fuel oil, diesel oil, gas oil and coal in that period.

The retroactive publication of these prices is not an administrative error: it is the usual mechanism of the settlement system for isolated electrical systems. Actual market prices are consolidated once the period closes and are used to regularize the provisional settlements that operators will have already received.

What does this regulation establish?

The resolution sets the reference prices for four fuels measured at port, which are the main inputs for electric generator groups in non-peninsular territories. These prices are not what the end consumer directly pays: they are the reference values that the Administration uses to calculate how much it should compensate each operator for their fuel costs under the special remuneration regime.

The special remuneration regime exists because generating electricity in isolated systems—islands or autonomous cities without connection to the peninsula—is structurally more expensive than in the peninsular system. The State compensates for that cost difference through periodic settlements. Fuel prices are the most relevant variable for calculating that compensation.

The resolution is published in May 2026 with effects on the second half of 2025 because the system operates with provisional settlements during the year and a subsequent regularization once definitive market price data is available.

Economic and operational impact

The economic impact of this resolution operates on two levels:

• For generator operators: The prices set determine the final amount of settlements for the second half of 2025. If the reference prices set are higher than those used in provisional settlements, the operator will receive an additional payment. If they are lower, there will be a reduction. This directly affects cash flow and 2025 results.
• For the national electrical system: Generation costs in non-peninsular territories are passed to the system through electrical tolls. The setting of these prices has an impact on electricity rates and the financing of the national electrical system, which ultimately affects all electricity consumers.

The resolution does not publish specific settlement amounts per operator, as those calculations are performed individually based on the actual production of each generator group during the semester. Fuel prices are the input data for those calculations.

Who does it affect?

• Operators of electric generator groups in the Canary Islands that receive regulated remuneration under the special regime for isolated systems.
• Operators of electric generator groups in the Balearic Islands under the same conditions.
• Operators of generation facilities in Ceuta covered by the special remuneration regime.
• Operators of generation facilities in Melilla covered by the special remuneration regime.
• Managers of the settlement system (National Commission for Markets and Competition and Red Eléctrica de España) that use these prices to calculate payments to operators.
• Electricity consumers in Spain indirectly, given that island generation costs are passed on through the national electrical system tolls.

Practical example

An operator of a diesel power plant in the Canary Islands will have received provisional settlements during the second half of 2025 calculated with estimated fuel prices. Once this resolution is published, the settlement system recalculates the correct amount using the reference prices at port now set for gas oil and diesel oil.

If the reference price set for diesel oil turns out to be higher than the provisional price used during the semester, the operator will receive in the regularization settlement the difference corresponding to all their production for the period. If the price is lower, that difference will be deducted in the next settlement.

This mechanism ensures that the compensation the operator receives reflects the actual fuel costs of the period, not prior estimates. For the operator's finance department, the publication of this resolution is the signal to review the provisional settlements received and estimate the final adjustment.

What should companies do now?

1. Review the provisional settlements received during the second half of 2025 and identify what fuel prices were used as reference in each one.
2. Compare those provisional prices with those now set in the resolution to estimate the direction and magnitude of the adjustment in the regularization settlement.
3. Update financial forecasts for 2025 if the estimated adjustment is materially relevant to results or cash flow.
4. Coordinate with the settlement system manager (CNMC or Red Eléctrica as appropriate) to confirm the schedule for the regularization settlement for the second half of 2025.
5. File the resolution as supporting documentation for the period settlements, along with production and fuel consumption records for each generator group.