When electricity is cheapest in Spain, and why it changes daily

“Electricity is always cheaper at night” stopped being true a while ago. Spain's electricity price runs on two clocks, and only one of them stands still.

Night stopped being the automatic answer

For years the rule fitted in one line: run things in the small hours. It was not wrong, but it has aged. The part of the bill charged by time band still rewards the small hours; the part that moves with the market no longer always does. With the solar capacity now in the system, the daily low lands on many days in the middle of the day, when the sun is strong and demand has not yet climbed. May 2026 was the month with the largest photovoltaic share of the Spanish generation mix on record, at 28.5 %.

So the honest answer is not an hour. It is a method: know which part of the price stands still, which part changes daily, and where to read today’s.

Two different clocks inside the same bill

The first one does not move. Tolls —what you pay for using the transmission and distribution networks— and charges —system costs shared out among consumers— are billed by band: peak, flat and off-peak. Article 7 of Circular 3/2020, issued by the CNMC (Spain’s markets and competition regulator), sets them, and on the Mainland, Monday to Friday on working days, they run like this: peak from 10:00 to 14:00 and from 18:00 to 22:00; flat from 08:00 to 10:00, from 14:00 to 18:00 and from 22:00 to 24:00; off-peak from 00:00 to 08:00. The same all year: the 2.0TD access tariff, the one almost every household is on, has no winter or summer season. The Balearic and Canary Islands share those exact hours; only Ceuta and Melilla shift them one hour later.

There is also a rule few people use: every hour of Saturdays, Sundays, 6 January and fixed-date national holidays is billed as off-peak. Fixed-date only. Good Friday moves every year, so it is billed like any ordinary Friday, with its peak and flat hours intact.

The second clock changes hourly. The PVPC —the Voluntary Price for the Small Consumer, Spain’s regulated electricity tariff— contains a production cost which, in the words of article 9 of Royal Decree 216/2014, «shall take a different value for each hour h». It is not grouped into peak, flat and off-peak: it is twenty-four different prices every day. Spain’s Ministry for the Ecological Transition describes it as a dynamic price fully indexed to the wholesale market, varying every hour. Since 1 January 2026 that component no longer simply copies the day-ahead market: 45 % of the signal comes from the day-ahead and intraday markets and 55 % from forward markets.

And there is the misunderstanding that runs through the whole subject: the time bands are real, but they govern tolls and charges, not the price of the energy. Because tolls and charges sit inside the PVPC, the bands do show up on the bill. They just are not what decides which hour is cheapest.

Why midday turned cheap

In the Spanish wholesale market the lowest prices —and the negative ones— cluster in the central hours of the day: plenty of solar output and demand that has not fully woken up. In the late afternoon, as the sun drops and household demand rises, the price rebounds. Since 28 May 2026 the floor for clearing prices in the European day-ahead market has been −600 €/MWh, so negative prices are not a textbook hypothesis.

The awkward part is that this market low usually falls inside the peak band, 10:00 to 14:00, exactly where tolls and charges are dearest. The regulated part of the energy term at peak is comfortably more than triple the flat one and of the order of thirty times the off-peak one. Add both pieces and the answer moves from day to day: some days the cheapest hour is in the small hours, other days it is at midday. No fixed rule replaces looking at the curve.

When the price is known, and where to read it

OMIE, the electricity market operator, closes bidding on the day-ahead market at 12:00 —Mainland Spanish time— and the results are firm at around 13:05. Red Eléctrica then calculates the PVPC and is required to publish it before 20:15 the day before supply, for each of the twenty-four hours of the following day. From that moment tomorrow’s price is no longer a forecast: it is what will be billed.

One detail that surprises people: since 1 October 2025 the wholesale market has traded in fifteen-minute periods, ninety-six a day, yet the PVPC that gets published is still hourly, with twenty-four values per day.

With PrecioLuz the daily routine is short:

1. Pick your zone. Mainland, Canary Islands, Balearic Islands, Ceuta or Melilla: each one has its own hourly price.
2. Read the day's curve. All twenty-four hours in green, amber and red, with the cheapest and the dearest marked by an arrow, and the day's minimum, average and maximum with the exact hour of each.
3. Set your own scale. You choose the thresholds of the five-level colour scale: what counts as dear in one home does not in another.
4. Let it tell you in the evening. When the next day's price is published, an alert arrives with the average, how it compares with today and the cheapest stretch.
5. Add the widget. The current band's price and the cheap hours on your Home Screen, so you never have to open anything.

What is worth moving, and what is not

Only shiftable loads shift: washing machine, dishwasher, tumble dryer, electric water heater, oven and electric car. Not the fridge, and barely the heating. It pays to be realistic about the size of it: moving one wash saves little, and that little shows up over a month, not on a single day’s bill.

Taxes do not change the ranking. VAT —21 % since 1 June 2026— and the Special Electricity Tax are applied on top of the PVPC and are percentages: they widen the gap in euros, but they do not change which hour is the cheap one.

And a warning that rarely gets printed: none of this turns into money unless your contract follows the hourly price. Only individuals and microenterprises with contracted power of 10 kW or less in every period may take the PVPC, and at the end of 2024 just 28.5 % of household consumers were on that tariff. On a fixed-price contract in the free market, starting the washing machine at three in the morning or three in the afternoon costs exactly the same on the energy term.

If you have solar panels, midday flips the calculation: those are the hours when your surplus is worth least, so consuming it yourself beats exporting it. Simplified surplus compensation is a discount on the bill, never an income; article 14 of Royal Decree 244/2019 forbids the value of the exported energy from exceeding the value of the energy drawn from the grid over the billing period. PrecioLuz shows the wholesale market price and surplus compensation, and warns about the hours when the surplus turns negative.

Check today's curve before you start the washing machine

PrecioLuz paints all twenty-four hours for your zone in green, amber and red, with the cheapest and the dearest marked by an arrow. Hourly prices, the day's curve and the evening alert are free.

Frequently asked questions