The Spanish electricity system is facing an unprecedented technical and regulatory dilemma after the blackout on 28 April. The critical issue now lies in how the cost of restarting the system will be distributed—an operation that not only required the activation of backup units but also created unresolved economic distortions.

Carlos Martín Graña, Head of Operations at ENERJOIN, identifies three possible models to approach this settlement, each with different implications for consumers and the market.

“If you publish a quarter-hourly cost, this cost will only be paid by those who had supply,” he points out. This first option—based on allocating costs according to the time at which supply was restored—is, in the executive’s view, unfeasible. “The few who gradually regained electricity would face disproportionate and unaffordable costs,” he explains.

Speaking with Strategic Energy Europe, the executive outlines a second approach: to calculate the total restart cost from 28 and 29 April and distribute it among all consumers over a short period. However, he warns that this could lead to significant tariff pressure. “If we spread the cost over just seven days, with low demand, the price could reach between 30 and 60 euros per megawatt hour,” he estimates.

Therefore, Graña advocates for a third option, which he deems the most reasonable: “Calculate all the costs of 28 and 29 April, divide them across the entire annual demand, and create a euro per megawatt concept to be applied throughout the following year.”

This approach would dilute the impact over time, reducing its effect on tariffs and avoiding inequalities.

From an operational perspective, the cost—hypothetically estimated at €10 million—would ultimately have to be borne by the entire system. “One way or another, the sector will definitely pay for it—and by extension, so will consumers,” he asserts. The mechanisms could be integrated via tariffs, network tolls, system charges, or even as a tariff deficit, he adds.

The final allocation mechanism is to be decided by the CNMC, while Red Eléctrica will carry out the technical settlement. Graña stresses that, even though the regulator is an independent authority, its involvement effectively represents a governmental stance: “If the CNMC is involved, then it’s as if the Government is indirectly stepping in.”

OMIE to activate an extraordinary market resettlement on 16 June

In parallel with the design of the cost allocation mechanism, the Iberian Market Operator (OMIE) has announced that it will conduct an extraordinary resettlement of the energy trading programmes for 28 and 29 April, correcting the market positions disrupted by the blackout.

“This has never happened before—or at least, I don’t recall it ever happening,” Graña notes, emphasising the unprecedented nature of the measure. The resettlement will affect retailers and generators that had secured positions in the day-ahead market but were unable to execute contracts due to the systemic outage.

Although this adjustment resolves the financial aspects of the market, it does not address the technical cost of the system restart, which remains undefined and is shaping up to be the regulator’s key challenge.

ACIE demands predictability amid rising system costs

The Association of Independent Energy Retailers (ACIE) expressed concern in an official statement, warning about the additional costs arising from the reinforced operation of the electricity system following the blackout.

“It is essential that the duration of the reinforcement of the Spanish electricity system is urgently determined and officially communicated to all involved stakeholders,” the statement reads. The association emphasises that the current lack of clarity prevents retailers from planning the tariff impacts, which may ultimately be passed on to end users.

Moreover, ACIE insists that any cost distribution scheme must be designed with fairness and transparency, calling for a clear intervention by the CNMC to safeguard market balance without favouring specific sectors.

This institutional demand aligns with Graña’s analysis, who maintains that the final mechanism must aim to minimise unequal tariff effects: “The impact will vary depending on how long the cost is spread out, but the key is to allocate it proportionally across total demand.”