A major reform is set to reshape European power trading. From 30 September, electricity on the day-ahead market will no longer be traded in hourly blocks but in 15-minute intervals. For Vattenfall, this marks more than a technical change: it is a key lever on the company’s path to fossil freedom. The new structure takes into account the weather dependency of renewable energies, increases system flexibility, and illustrates how market design and the integration of wind and solar go hand in hand.
“The move to quarter-hour products is a true paradigm shift for the energy transition,” says Jörg Seidel, Head of Short-Term Asset Optimization at Vattenfall. “Even though we will have to wait and see what the specific impact on our plant operations will be, the reform shows where the market is heading: it opens up opportunities to integrate electricity from wind and solar power into the market even more efficiently – and brings us closer to a future in which everyone has the choice to travel, produce and live without fossil fuels.”
Until now, day-ahead trading on EPEX SPOT was based on hourly blocks, a rigid framework that made it harder to reflect the variability of renewable power. This led to inefficient price formation and frequent intraday corrections. With 15-minute products, short-term fluctuations will already be captured in the day-ahead auction. The starting point for intraday trading is therefore much more accurate.
“Generation and demand can now be mapped much more precisely,” explains Seidel. “We can submit more accurate forecasts, market renewables more effectively, deploy batteries and pumped storage more efficiently, and significantly increase system flexibility.” For renewable operators, this means better marketing options, lower balancing costs, and more planning security.
Consumers could also benefit. More precise price signals open new savings potential through dynamic tariffs and smart meters, enabling households to use electricity when it is cheapest. This could make heat pumps, PV systems, batteries, and EV charging more efficient and affordable.
“Flexibility is becoming the currency of the energy transition,” adds Seidel. “In the future, those who manage their heat pump, storage, or EV on a quarter-hour basis not only save money but also consume more renewable electricity.”
The reform is part of an EU directive requiring all power markets to harmonize trading and settlement periods to 15 minutes. It also feeds into the Single Day-Ahead Coupling (SDAC), designed to increase efficiency and cross-border electricity flows across Europe.
“This reform strengthens not only the market but also our ambition to enable fossil freedom while remaining economically successful,” stresses Seidel. “The more precisely renewable generation can be represented, the faster and more efficiently the energy transition will succeed.”
The new trading regime will take effect with the first auction on 30 September 2025, marking the start of a new phase in the European power market.
