If you follow the electricity price (or suffer from it 😅), this matters to you: from 1 October 2025, the day-ahead electricity market in Europe —and therefore in Spain— moves from working by the hour to working in 15-minute intervals. In other words, 96 prices a day instead of 24.
It may look like a ‘technical’ change, but it actually marks a turning point in understanding (and optimising) energy in businesses, industry and self-consumption.
What exactly has changed?
Until now, the wholesale market (the ‘pool’) cleared one price for each hour of the day. Since the change:
- Each hour is divided into 4 slots: 00:00–00:15, 00:15–00:30, 00:30–00:45, 00:45–01:00, etc.
- So we move to 96 price periods a day.
- OMIE (the Iberian electricity market operator) already reflects this with periods such as H1Q1 (first quarter of the first hour), etc.
And note the date: the ‘historic’ market clearing for the switch took place on 30 September 2025, already producing the 96 prices for energy delivered on 1 October.
Why is this change happening? (the underlying reason)
The short answer: because the electricity system no longer behaves ‘by the hour’.
With renewables (solar and wind) carrying ever more weight, generation can vary considerably within a single hour. With prices every 15 minutes:
- The price better reflects what it costs to produce electricity at each moment, matching supply and demand more precisely.
- Europe harmonises the electricity market through the EU single day-ahead coupling (SDAC), so that all countries ‘play’ with the same time unit.
- It is in step with the system’s shift towards finer balancing processes: Spain has also been adapting its imbalance settlement to 15 minutes, which is key for a more renewable and variable system.
Who does it affect?
It depends on your type of contract and how your consumption is metered:
- Companies on a pool-indexed tariff: the ‘reference’ price becomes more granular (and therefore more opportunities to optimise appear… along with more intra-hour variability).
- Industry and consumers with a detailed load profile: this change has much more impact, because the real cost can differ within the same hour.
- Households: in practice, the immediate impact may be limited for many domestic users, depending on how the measure is applied and the effective granularity of meter reading/billing.
What opportunities does it open up for a business?
This is where it gets interesting. With prices every 15 minutes, saving is no longer about ‘changing the hour’ but about ‘moving specific processes’:
- Shift flexible loads (HVAC, pumping, charging, staged furnaces, compressors, etc.) to cheaper quarter-hours.
- Detect micro-peaks: sometimes the expensive peak no longer lasts 1 hour… it lasts 15 minutes (and can be avoided).
- Optimise self-consumption and batteries: with finer time detail, you can better fine-tune when to use the grid, when to draw on the battery and when to charge it.
- Better analysis of €/unit produced (€/tonne, €/part, €/batch): if your production and energy data have fine resolution, the KPI improves enormously.
How does Powercloud approach it?
At Powercloud, this change translates into something very concrete: more precision to turn energy into euros, and euros into decisions.
Some practical ideas (very ‘shop-floor’):
- Energy cost per quarter-hour by line/process/site.
- Alerts if your consumption falls right in the most expensive quarter-hours of the day.
- Weekly comparisons: ‘my 10 most expensive quarter-hours’ vs ‘my 10 cheapest quarter-hours’.
- Business KPIs (€/t, €/unit) with better traceability.
Wrapping up
The quarter-hourly market is not a passing fad: it is the natural consequence of a more dynamic, more renewable and more European electricity system. And for businesses, it is a clear opportunity: if you can measure, you can understand; if you can understand, you can optimise.
If you like, in a future post we can bring this down to earth with a real example (e.g. a plant with compressors + self-consumption) and show which decisions emerge when you go from 24 to 96 prices a day.
