On October 1, 2025, the European electricity market will experience one of its most significant transformations of the last decade: the implementation of the quarter-hourly market. This change, which involves transitioning from 60-minute trading intervals to 15-minute intervals, is not merely a technical adjustment, but a fundamental step toward a more flexible, efficient energy system aligned with the realities of the energy transition. For large energy-intensive companies, this new paradigm opens up a range of opportunities to optimize their costs and energy management, while also presenting important adaptation challenges.

What is the Quarter-Hourly Market and why is it so important?

The transition to the quarter-hourly market, technically known as MTU15 (Market Time Unit 15 minutes), means that the daily electricity market will cease operating with 24 hourly prices and instead have 96 different prices each day, one for every quarter-hour. This increased granularity will allow for much more precise reflection of supply and demand fluctuations in real-time, a crucial factor in an energy mix with increasing penetration of intermittent renewable sources, such as solar and wind power.

The main objective, driven by European regulation through Regulation (EU) 2019/943, is twofold. On one hand, to facilitate the system operator’s task (in Spain, Red Eléctrica) of balancing generation and demand, improving system security and efficiency. On the other hand, to offer market agents, from generators to large consumers, more precise tools to manage their consumption and production profiles, reducing imbalances and optimizing their energy buying and selling strategies.

According to OMIE, the Iberian market operator, this measure “offers market agents greater flexibility to manage their consumption and production forecasts”.

The Path to Implementation: Challenges Overcome

The transition has not been without difficulties. Initially scheduled for June 2025, the launch was postponed to October 1 due to the lack of technical readiness of some key European actors. The EPEX SPOT platform, which manages markets in countries like Germany and France, warned that test results were “well below standard,” with failures that could cause serious operational problems.

These technical problems, especially in the Single Day-Ahead Coupling (SDAC) mechanism, underscore the enormous complexity this change entails. During tests conducted in February and March 2025, approximately 20% of sessions ended in unexpected total decoupling, an incident never before seen in market coupling history. The decision to postpone the date sought to ensure a robust and safe transition for all market participants.

Impact and Opportunities for Energy-Intensive Companies

For large industrial consumers, the quarter-hourly market represents a paradigm shift with significant potential benefits. They will be the main indirect beneficiaries of this new system, as a more competitive market adapted to technological realities translates into access to fairer and more transparent prices.

Key Benefits for Energy-Intensive Companies

• More representative prices: Quarter-hourly pricing will better capture moments of low demand or high renewable production, offering significant savings opportunities for those who can adapt their consumption.
• Active demand management: New avenues open for implementing demand-response solutions, allowing companies to monetize their operational flexibility and substantially reduce their electricity bills.
• Reduced imbalance costs: Greater precision in consumption scheduling can minimize penalties for imbalances between purchased and consumed energy, especially relevant since imbalance settlement has been conducted in quarter-hourly format since December 2024.
• Greater transparency: A more granular market offers clearer insight into price dynamics, facilitating strategic decision-making and identification of optimal consumption patterns.
• Volatility exploitation: Companies will be able to benefit from greater intraday volatility, with prices that can be up to 50% cheaper in certain periods and even negative during central hours of the day.

Technical Transformation: From Energy to Power

A fundamental aspect of the change is the modification in bid structure. The new system requires that bids be made by nominating demanded power (MW) for each quarter-hour, instead of energy (MWh) for each hour as was done previously. This technical change allows for more precise balancing between generation and demand, especially important in a context of increasing integration of intermittent renewable sources.

This transformation will require energy-intensive companies to have greater analytical capacity and more active energy management. Those that invest in digitalization and automation of their processes will be better positioned to capitalize on these opportunities and compete effectively in the new market environment.

Challenges and Preparation: The Key to Success

Adapting to the quarter-hourly market is not trivial. It involves an enormous effort to integrate all applications and processes into this new structure. Generators, retailers, and large consumers must adapt their systems to be able to send and receive information in quarter-hourly format to market operators (OMIE) and system operators (Red Eléctrica).

The key to success will lie in companies’ ability to:

Digitalize and automate their consumption monitoring and control systems, implementing technologies that allow real-time response to market signals. Develop more sophisticated operating strategies to actively participate in intraday markets, taking advantage of arbitrage opportunities that will arise from greater temporal granularity. Have specialized energy consulting that allows them to navigate the complexity of the new market and design customized purchasing strategies, adapted to their specific consumption profiles and operational flexibility.

The Spanish Context: Advanced Preparation

Spain is in a relatively advanced position in this transition. Intraday markets already adopted 15-minute products since March 18, 2025, although their impact has been limited so far, as many retailers continue billing on an hourly basis. Meanwhile, Red Eléctrica has been working with quarter-hourly forecasts since March 2024, especially in the balancing market, where large plants are already measured and settled with this granularity.

This prior experience provides Spanish companies with a competitive advantage in adapting to the new system, although full implementation in the day-ahead market will represent a significant qualitative leap.

Conclusion: A Strategic Opportunity

The quarter-hourly market is much more than a simple technical change; it is a necessary evolution of the electricity market to adapt to the era of renewables and digitalization. For large energy-intensive companies, it represents a strategic opportunity to transform their energy management, moving from being passive consumers to active players capable of optimizing their costs and contributing to system stability.

The transition will require investment and adaptation, but companies that embrace this change with a well-defined strategy will be laying the foundations for greater competitiveness and sustainability in the new energy paradigm. At Magnus Commodities, we are prepared to accompany our clients in this transformation, offering the specialized consulting and necessary tools to maximize the opportunities presented by the quarter-hourly market.