Para For many companies with indexed contracts, the costs that have grown the most in recent months are neither the contracted capacity nor the energy consumed. They are the adjustments applied by Red Eléctrica de España (REE), which have an increasingly greater and more unpredictable impact on the final price.

These adjustments—also called balancing services, reserves, or deviations—are corrections that REE makes in real time to ensure a balance between energy generation and consumption. With the increase in renewable energy production, which is more variable and difficult to predict, these corrections have become more frequent and more costly. And their presence on the bill is often unclear.

Let’s analyze the evolution of the price of these adjustments in recent years, taking the month of May as a reference:

  • 2019: 1,85 €/MWh
  • 2020: 3,54 €/MWh
  • 2021: 4,10 €/MWh
  • 2022: 8,30 €/MWh
  • 2023: 10,65 €/MWh
  • 2024: 14,99 €/MWh
  • 2025: 25,82 €/MWh

Adjustment costs evolution

In six years, these costs included in your electricity bill have increased by 1,300%, to the point that adjustment services cost more than the energy consumed. In other words, many companies are paying more to “correct” energy distribution than for energy itself.

Paradigm Shift

These costs traditionally went unnoticed. They had a very minimal impact on the bill but have progressively gained weight and volatility as the electricity mix incorporates more renewable generation. Solar and wind energy production is, by its very nature, highly variable, forcing Red Eléctrica (REE) to make more real-time corrections, especially in months like spring and fall, when renewable activity intensifies. In contrast, when nuclear energy was primarily used, production was much more stable throughout the year, and corrections were less necessary.

The constant increase in demand for 100% renewable energy, combined with events such as the blackout on April 28, does not suggest that the scenario will change. On the contrary. The impact of the adjustments, at least until the technology and electrical infrastructure change, will be increasingly significant.

And as if that were not enough, since last December, REE has been calculating adjustments with a 15-minute resolution (due to the entry into force of the ISP-15 settlement). This model provides greater precision but also means that any small deviation in demand or generation scheduling can have a direct economic impact.

Companies with indexed contracts should be aware that these microvariations can alter the cost of their energy consumption every 15 minutes.

And what about fixed-price contracts?

Although fixed-price contracts may seem like a safe option, they have more disadvantages than they appear. It’s true that they allow for predicting the cost of the energy term, but this does not imply real stability or guaranteed savings.

First, the adjustment costs applied by the REE are also included, but opaquely. Retailers estimate them with their own formulas based on past scenarios and risk premiums. The result? Companies end up paying these costs anyway, often with a considerable premium overcost to cover the safety margin applied by the retailer.

This margin, which can grow significantly in highly unstable contexts like the current one, means that the final price per MWh is often much higher than that of a well-managed indexed contract. The company pays more simply to avoid volatility, but often ends up assuming an inflated cost that’s disconnected from market reality.

Furthermore, “fixed price” doesn’t mean “fixed bill.” Tolls, charges, taxes, and additional services remain variable and can be updated throughout the term of the contract. And if that weren’t enough, many fixed-price contracts include adjustment clauses that allow the agreed price to be revised if there are significant deviations.

In short: fixed-price contracts can convey a false sense of control, but they often entail unjustified overcharges. For many companies, especially those that can afford active consumption management, opting for an indexed contract with professional support is a more efficient and cost-effective strategy today.

Buying energy is easy. Paying a fair price is extraordinarily complicated. Efficient energy management doesn’t just involve consuming less, but also better understanding how it’s billed and always adopting the best purchasing strategy. And this is what we do at Energy Tools.

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