Starting October 1, electricity prices will no longer be set hourly, but every 15 minutes. This means there will be 96 different prices each day instead of 24. This adjustment seeks to bring the tariff closer to the reality of real-time production and consumption and achieve the goal of increasing predictability in energy costs, offering greater stability.
This measure is neither new nor improvised. Already in 2017, EU Regulation 2017/2195 and later EU Regulation 2019/943 established that the settlement period for deviations should be reduced from 60 to 15 minutes. This will require each electricity company to declare how much energy it will produce or consume in each quarter of an hour and, if it deviates, it will receive a penalty.
In Spain, the tests began last year under the supervision of Red Eléctrica and OMIE. The CNMC designed a phased transition: first to the continuous intraday market (March 2025) and then to the daily market (June). However, the lack of preparation of some participants forced the delay in implementation until September 30, with actual effect on October 1. Furthermore, the change has entailed redesigning the auction systems and coordinating with neighboring markets such as France, Portugal, and Morocco.
What changes for consumers?
Those subject to the regulated tariff (PVPC) will continue to see average hourly prices on their bills.
Free market users will also notice no changes, as their contracts are fixed-price or time-of-use. They won’t have to check the rate every fifteen minutes to run the washing machine; as long as the meters aren’t changed, bills will continue to be hourly.
However, the measure primarily affects consumers with smart meters that can record consumption in 15-minute periods.
Initially, there is a technical problem, as current home meters only record hourly consumption. To avoid replacing millions of devices, Red Eléctrica will apply a linear interpolation method that estimates 15-minute consumption based on hourly readings.
The main beneficiaries will be the electro-intensive industry, storage facilities, and self-consumption projects, which will be able to better adjust their consumption to take advantage of the cheapest times of day. SMEs with management skills could also benefit.
For households with solar panels or small self-consumption facilities, the 15-minute priced market opens a window of opportunity. These consumers will be able to better optimize when to consume their own energy and when to feed it into the grid, taking advantage of the lowest and highest price ranges. For this reason, storage will be key. With prices changing every 15 minutes, domestic or industrial batteries will be able to charge at the cheapest times and discharge at the most expensive, multiplying the savings potential.
The new system fits better with the intermittent nature of solar and wind power: a passing cloud or a gust of wind will be reflected in the market in near real time, allowing for a more fluid integration of renewables. However, the meters are still hourly. Most self-consumption households will continue to see average hourly prices, at least until the metering systems are updated.
Fewer deviations, more renewables. Until now, the market set an hourly price, but neither consumption nor generation are linear over 60 minutes. With 15-minute intervals, these variations can be better adjusted, reducing the overcharges of adjustment markets that end up being reflected in the bill.
The new system fits better with renewable energies. Their production—highly variable over short periods of time—is more naturally integrated into 15-minute intervals.
Some disadvantages can be perceived. Following the blackout on April 28th in the Iberian Peninsula, the government had to reconsider the measure for fear that the greater granularity would cause grid instability.
The transition has also entailed an enormous technical and economic burden. Operators, distributors, and retailers have had to redesign their IT systems, with a persistent problem with grid distribution.
