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Glossary · Energy industry & energy transition

Dynamic Tariff

Dynamic Tariff electricity tariff Real-Time Price flexibility consumption

Definition and basic principle

Dynamic Tariff is the English term for a dynamic electricity tariff. It refers to an electricity supply contract in which the energy price changes over time. It follows a previously agreed rule that ties it to prices on the wholesale market. EU law describes such a contract as follows: it reflects the price fluctuations on the spot markets, that is, on the day-ahead and intraday markets, at intervals at least as fine as the settlement intervals of the respective market. In practice, most household tariffs are based on the day-ahead price of their own bidding zone. A separate price then applies to each time interval of consumption, rather than a single uniform price for every kilowatt-hour.

An important innovation concerns the time resolution. Until September 2025, the European coupled day-ahead auction (SDAC) determined hourly prices. Since the delivery day of 1 October 2025, it has operated with 15-minute intervals in all European bidding zones. The frequently read statement that dynamic tariffs follow the hourly exchange price is therefore outdated. The exchange now delivers quarter-hour prices. Whether a tariff passes these on directly or, for example, averages them into hourly values is governed by the respective contract terms.

Unit, metering and load profile

What is billed is the electrical energy drawn, in kilowatt-hours, not the connection capacity. A household can therefore consume just as much electricity per year as before and still have different costs if it shifts its consumption in time. The load profile therefore becomes decisive: when does the electricity consumption occur, how high is the power in the individual time windows, and which appliances can be shifted without loss of benefit?

This requires consumption to be measured with time resolution. A Ferraris meter shows only the total consumption since the last reading. It cannot be used to determine whether a kilowatt-hour was drawn at midday or at night. In Germany, the law therefore ties the obligation to offer a dynamic tariff to customers who have an intelligent metering system within the meaning of the Metering Point Operation Act (Messstellenbetriebsgesetz). The tariff is thus not just a product of the supplier. It also depends on metering, data transmission, market communication and billing systems.

Distinction from other tariff types

  • Fixed-price tariff: The energy price remains the same over the contract term, even if the supplier purchases at fluctuating prices in the background. The supplier bears the procurement risk and factors it into the price.

  • Time-variable tariff or time-of-use tariff: It has fixed price windows known in advance, for example a cheaper night-time price. However, the prices do not continuously follow the exchange.

  • Dynamic tariff: The price changes according to an external market rule, usually with the day-ahead price. The term real-time price is usually not quite accurate for this. Day-ahead prices are set on the previous day for all intervals of the following day. This is even an advantage, because charging schedules and control systems can thereby plan ahead.

Legal framework in the EU and in Germany

EU: Under Article 11 of the Internal Electricity Market Directive (EU) 2019/944 as amended in 2024, Member States ensure that final customers with a smart meter can request a contract with dynamic electricity prices. Suppliers must inform consumers about the opportunities, costs and risks. Before switching to a dynamic tariff, they need the customer's consent. In addition, there is an entitlement to fixed-price contracts with a duration of at least one year. Suppliers with more than 200,000 final customers must offer such contracts.

Germany: Section 41a(2) of the Energy Industry Act (EnWG) initially obliged only suppliers with more than 100,000 final consumers to offer a contract with a dynamic tariff. Since 1 January 2025, the obligation has applied to all electricity suppliers, towards final consumers with an intelligent metering system. Since that date, the obligated suppliers must, on request, also offer the contract without grid use and metering point operation, if the customer has arranged both themselves. The current version of the provision also contains comprehensive information obligations on costs, advantages, disadvantages and risks. Before concluding or renewing a contract, the supplier must hand over a short contract summary with all price components. Anyone who offers exclusively dynamic tariffs does not have to offer a fixed-price contract under paragraph 4.

The obligation to offer does not mean that every interested party will get a contract. According to the Bundesnetzagentur (Federal Network Agency), freedom of contract applies. A supplier therefore does not have to conclude a contract with every interested party. As a rule, there is no special termination right for switching to a dynamic tariff. The usual rules on term and termination apply.

Why dynamic tariffs are gaining importance

With more wind and solar power, wholesale prices fluctuate more strongly. These plants have low variable costs but do not generate according to a fixed consumption pattern. With high feed-in and low demand, prices can become very low or even negative. With high demand and little wind and sun, they rise. A dynamic tariff passes these scarcity and surplus signals on to flexible consumers. However, this only works if consumption can actually be shifted. A refrigerator, lighting or a running stove offer hardly any usable flexibility. It is different with electric cars, heat pumps with building or hot-water storage, battery storage and some commercial processes. An electric car must be charged by morning, but does not have to charge at full power at 6 p.m.

Dynamic tariffs become practically usable above all with automation. An energy management system, a wallbox or a storage controller can read in the prices for the following day and schedule operation in favourable intervals. In doing so, they must take into account comfort limits, technical operating conditions and possible grid requirements. Price apps alone are not sufficient for many households.

Common misunderstandings and limits

A dynamic tariff does not automatically reduce costs. Favourable intervals only help if a significant amount of electricity is also consumed in them or consumption can be shifted there. Anyone who draws electricity mainly at expensive times and has no controllable appliances may end up paying more than with a fixed price. With a dynamic tariff, the customer bears a larger share of the price risk, including in periods of persistently high wholesale prices. In return, they can take advantage of favourable times.

The exchange price is also only one part of the end-customer price. Taxes, levies, surcharges, metering charges, base prices and the supplier's margin generally do not depend on the exchange price of the respective interval. The total household electricity price therefore fluctuates significantly less than the exchange price. For grid charges, this now applies only to a limited extent. Since 1 April 2025, grid operators must offer operators of a controllable consumption device under Section 14a EnWG a time-variable grid charge, the so-called Module 3. It can only be chosen together with the flat-rate reduction under Module 1. The three tariff levels of this grid charge are set by the grid operator. They follow grid utilisation and not the exchange. It can be combined with a dynamic supply tariff, but it is not part of it.

Dynamic tariffs are also not grid control. The exchange price shows scarcity across an entire bidding zone, not the situation in the local distribution grid. If many electric cars in one street charge simultaneously in a cheap quarter-hour, a bottleneck can arise there despite a low wholesale price. Conversely, the exchange price can be high even though the local grid is uncongested. Responsibilities are separate: suppliers translate market prices into tariffs, grid operators ensure grid security, metering point operators supply the data, and regulatory authorities set the framework.

Negative electricity prices are also often misunderstood. A negative exchange price does not mean that electricity is free for the end customer or that the customer receives money. It shows that additional demand on the wholesale market is valuable in that interval or that generators can reduce their output only at a cost. For the end customer, the other price components still apply. In addition, contract terms can determine how far negative prices are passed on. For the electricity system, a response to them can nevertheless be useful, because it increases consumption in times of high renewable feed-in and can reduce the curtailment of plants.

Placement within the electricity system

The term stands for involving the demand side in the electricity market. Previously, power plants followed consumption, and consumers paid largely uniform prices. With more renewable generation, more electrification and more controllable loads, it is worthwhile to also adjust the timing of consumption. The term must be distinguished from residual load. Residual load is the demand that, after deducting wind and solar power, still has to be met by dispatchable generation, storage, imports or flexible demand. A dynamic tariff can respond to such situations if prices reflect them. However, it is not itself a technical quantity but a contractual pricing model.

In summary, a dynamic tariff makes visible that electricity is worth different amounts at different times. It guarantees neither cheaper nor renewable electricity and replaces neither grid expansion nor storage, system services or clear rules for controllable consumers. How well it works depends on which price components are variable, how finely metering is done, which appliances are controllable, and how market and grid signals interact.

Sources

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Edited by eCMS on 11.11.2026 19:42

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