What is a dynamic electricity tariff?

A dynamic electricity tariff is a plan where the unit price you pay for electricity changes throughout the day, following the wholesale market instead of staying fixed. Prices are usually published a day ahead for each hour or half-hour, so you can know in advance when power will be cheap and when it will be expensive.

Because renewable generation and demand vary constantly, the wholesale price can swing dramatically — sometimes several times higher at the evening peak than in the middle of the night, and occasionally even negative when there is a surplus of wind or solar.

A fixed tariff charges the same rate at all hours. A day/night tariff (like Economy 7 in the UK) has two blocks — a cheaper night rate and a pricier day rate. A dynamic tariff goes further: the price follows the market for every settlement period, so the cheapest window moves depending on weather and demand.

Dynamic tariffs reward flexibility. If you can move consumption — charging an EV, heating water, running a battery — into the cheapest hours, you capture the low prices. If you can’t shift, a dynamic tariff can actually cost more during peaks.

Across Europe, day-ahead wholesale prices are set on regional markets: the all-island SEM in Ireland, the GB wholesale market in the UK, EPEX SPOT in much of continental Europe, Nord Pool in the Nordics and OMIE in Iberia. ENTSO-E publishes the day-ahead prices that many dynamic suppliers pass through.

You can see how pricing works for your country, including typical day and off-peak rates, on the FYXO country pages.

The savings from a dynamic tariff only materialise if your flexible loads actually run in the cheap hours — and nobody wants to check prices every hour. This is exactly what automation solves: FYXO watches the wholesale prices 24/7 and shifts your EV charger, battery, hot water and other flexible loads into the cheapest half-hours, while always respecting your ready-by times and comfort limits.