Frequently Asked Questions

From Red Eléctrica de España (ESIOS, file 70, PVPC 2.0TD), the official figure of the regulated tariff. No energy retailers and no comparison sites behind it. Tomorrow’s prices are published between 20:15 and 20:20, mainland Spanish time. More detail: What time tomorrow’s electricity price is published (in Spanish).

Once a day, when REE publishes tomorrow’s prices. The app downloads them in the background and keeps the history on the iPhone for the calendar and the comparisons. On screen you have yesterday, today and tomorrow.

With three alerts you switch on in Settings. “Mejor hora del día” (best hour of the day) arrives 5, 10, 15 or 30 minutes before the cheapest hour, and gives you the whole stretch if several hours in a row cost almost the same. “Precios de mañana” (tomorrow’s prices) arrives at 20:20 with the best hour of the next day. “Oferta puntual” (one‑off bargain) warns you 15 minutes before an unusually cheap hour. They are local iPhone notifications: no server, no email, no account.

“Precio ahora” (this hour’s price with its colour), “Hoy — mejores y próximas” (today’s best and upcoming hours), “2 h baratas” (the next cheapest two‑hour stretch, meant for the washing machine and the dishwasher) and lock screen and StandBy widgets. On top of that, the Live Activity keeps the current price and the best hour of the day on the lock screen and in the Dynamic Island.

“Lavadora barata en Precio de la Luz” and “Lavavajillas barato en Precio de la Luz” (cheap washing machine, cheap dishwasher): Siri answers with the best stretch of two hours in a row left today, its average price and how far it is from the day’s average. You can also ask it for the electricity price right now. The shortcuts come ready to use in the Shortcuts app. Guide: When to run the washing machine (in Spanish).

The app shows the PVPC, the regulated tariff. If you are on a fixed‑price free‑market tariff, your price does not change by the hour and the app works as a reference for the market, not for your bill. If your tariff is indexed, the cheap and expensive hours generally match the PVPC ones even if the exact price is another one.

No. The app tells you when; you decide. There is no integration with smart plugs or with HomeKit. The closest thing to an automation are the Siri shortcuts, which you can combine in the Shortcuts app.

The app does not export CSV. The same data is public in JSON on the web: today’s data (in Spanish) and one file per day, and in Red Eléctrica’s own ESIOS.

On iPhone with iOS 26 or later. Without an iPhone at hand, the website precioluz.natural-apps.com shows the same prices in any browser (in Spanish). There is no Android version.

Yes. No ads, no subscription, no in‑app purchases and no sign‑up. If you find it useful, all we ask for is a rating on the App Store.

None. The App Store listing says “No data collected”: there is no account, there is no analytics inside the app and the alerts are worked out on the iPhone. As there is no account, there is nothing to erase: uninstalling the app removes everything.

Downloading the prices needs a connection. Once they are downloaded, the alerts fire on time even without a network and the widgets keep showing the last thing they drew. The prices of a new day arrive when the iPhone has a connection again.

Compare it with file 70 of ESIOS, which is the source. If it still does not add up, write to us at natural.learning.apps@gmail.com with the date and the hour and we will look into it.

In the upcoming version 1.72 you will be able to pick your zone in Settings → Zone: mainland Spain, the Balearic Islands, the Canary Islands, Ceuta and Melilla. The Canary Islands will see the hours in their own local time and will get tomorrow’s prices at 19:20, and Ceuta and Melilla will have their own price series, different from the mainland one. Version 1.72 is not on the App Store yet: the current version shows the mainland prices.