Short Definition
Dynamic electricity tariffs are electricity supply contracts in which the energy price changes at short intervals in line with spot market prices. Day-ahead prices often serve as the basis. This allows consumers to shift their electricity consumption to lower-price periods, while also exposing them to the risk of rising market prices.
Dynamic Electricity Tariffs at a Glance
- The variable energy price follows short-term electricity market prices, while other price components may remain fixed or be regulated separately, depending on the contract.
- Economic benefits arise primarily when a battery energy storage system (BESS) or flexible loads can respond specifically to price signals.
- Since 1 January 2025, all electricity suppliers have been required to offer dynamic electricity tariffs to final consumers equipped with a smart metering system.
- Dynamic consumption tariffs apply to purchased electricity and must be distinguished from the direct marketing of exported energy.
How Do Dynamic Electricity Tariffs Work?
With a dynamic electricity tariff, the electricity supplier passes fluctuations in spot market prices on to the energy price according to the pricing formula defined in the contract. Day-ahead market prices are often used as the basis. Supplier markups and other price components may be added to the wholesale market prices. Grid charges, taxes and levies do not automatically vary to the same extent. The relevant factor is therefore the total contractual electricity price, not merely the published wholesale market price.
A smart metering system records electricity consumption at defined time intervals and provides the data required for billing. Without changes in consumption patterns or automated control, the economic potential of a dynamic tariff can usually only be utilised to a limited extent. At the same time, there remains a risk that high electricity consumption will occur during expensive price intervals.
Once the relevant market or tariff prices have been published, an EMS can retrieve them via an external interface and plan operation for the upcoming period. Price, load and PV forecasts can also be incorporated into this planning. The EMS may consider factors such as expected electricity consumption, PV generation, the state of charge and power limits of the BESS, as well as constraints at the grid connection point. During operation, current measurements and system states are monitored so that setpoints or schedules can be adjusted in response to deviations and changing operating conditions.
Where Are Dynamic Electricity Tariffs Used?
- BESS: The battery can be charged during low-price periods and used to supply the site when electricity purchase prices are high. Charging and discharging are economically viable only if the expected price difference exceeds efficiency losses, potential cycle-related storage costs and any other relevant costs.
- Flexible loads: Heat pumps, charging infrastructure or shiftable production processes can preferably be operated during lower-price periods.
- PV and storage systems: Tariff-based control can be combined with PV self-consumption, load forecasting and peak shaving. Potential conflicts between the objectives of these applications must be taken into account.
Opportunities, Limitations and Requirements
Dynamic electricity tariffs can reduce electricity purchasing costs and create incentives to consume electricity during periods of high availability. However, their potential depends on price fluctuations, the available flexibility, and tariff, metering and control costs. Without shiftable loads or a BESS, a fixed tariff may provide greater cost predictability.
In addition to a suitable electricity supply contract, automated utilisation requires a smart metering system, controllable assets and appropriate communication interfaces. Reliable measurement data, defined operating limits and a fallback strategy are also important. Negative electricity prices are a possible special case and are addressed in the separate article “Negative Electricity Prices”.
How Does EcoPhi Support Dynamic Electricity Tariffs?
EcoPhi can receive electricity prices or price forecasts through external interfaces and use them for project-specific control logic. The EMS can control BESS and flexible loads based on defined price thresholds or optimised operating schedules. Factors such as PV forecasts, site consumption, state of charge, power limits, grid connection limits and other applications can be incorporated into the control strategy.
The specific implementation depends on the available data and device interfaces. EcoPhi provides the technical monitoring, communication and control layer, but it is not an electricity supplier and does not offer its own dynamic electricity tariff.
Brief Summary
Dynamic electricity tariffs link part of the electricity cost to short-term market prices. They are particularly relevant for sites with automatically controllable BESS or flexible loads. Whether they provide an economic advantage depends on the tariff model, price patterns and the amount of flexibility that can actually be utilised.
FAQ on Dynamic Electricity Tariffs
Is a Smart Meter Required for a Dynamic Electricity Tariff?
Yes. It records electricity consumption at defined time intervals and enables consumption to be allocated to the corresponding price intervals.
Is the Entire Electricity Price Variable Under a Dynamic Tariff?
Not necessarily. In many cases, it is primarily the market-dependent energy price that changes. Depending on the contract, grid charges, taxes, levies, metering costs and supplier markups may remain fixed or be calculated differently.
What Is the Difference Between a Dynamic Electricity Tariff and Direct Marketing?
A dynamic electricity tariff concerns the price paid by a consumer for purchased electricity. With direct marketing, by contrast, electricity exported by a generation system or a suitable storage concept is sold on the market.
Can an EMS Respond Automatically to Dynamic Prices?
Yes, provided that price data are available and the connected assets are controllable. The EMS can combine price thresholds or operating schedules with technical operating limits and other optimisation objectives.