The day-ahead price is the wholesale electricity price for a specific delivery interval on the following day, determined in an exchange auction the day before delivery. It applies to a particular bidding zone.
Day-Ahead Prices at a Glance
- Prices differ by delivery interval and bidding zone.
- The published price curve supports advance operational planning.
- The wholesale price is only one component of actual electricity costs.
How Are Day-Ahead Prices Determined?
Market participants submit bids to buy or sell electricity volumes with price limits. European market coupling determines traded volumes and a uniform clearing price within each bidding zone for each delivery interval. It accounts for available cross-border transmission capacity.
Key price drivers include consumption, photovoltaic and wind generation, power plant availability, and fuel and CO₂ costs.
Since delivery day 1 October 2025, the coupled European day-ahead market has used 15-minute intervals. A 24-hour day comprises 96 quarter-hourly prices per bidding zone. A daily average merely summarises these prices. Subsequent intraday trades have their own prices and do not change the established day-ahead prices.
The usual unit is €/MWh: 100 €/MWh equals 10 euro cents/kWh, excluding other price components.
How Do Energy Management Systems Use These Prices?
An energy management system (EMS) can charge battery storage during low-price periods and discharge it to meet on-site demand when electricity purchase prices are higher. Flexible loads, such as charging points, can also use lower-price intervals.
The EMS must comply with technical operating limits. Depending on the system and strategy, optimisation also considers photovoltaic and load forecasts, state of charge, efficiency, battery degradation, and other operating objectives.
Price-based load shifting is worthwhile when the electricity supply or marketing contract makes price differences financially accessible and the savings or additional revenues exceed additional costs, including losses and degradation. Grid charges, taxes, levies, and supplier markups may apply. Negative wholesale prices therefore do not automatically mean free electricity. Similarly, a low price does not guarantee available capacity in the local grid.
Day-Ahead Prices in EcoPhi Projects
Day-ahead prices can serve as external inputs for price-based EMS strategies. This requires a suitable price data connection, correctly assigned delivery intervals, and appropriate equipment interfaces. Implementation depends on the project and may require additional integration work. The technical execution of operating schedules is separate from electricity trading, balance group management, and commercial settlement.
Frequently Asked Questions
What is the difference between day-ahead and intraday prices?
Day-ahead prices are determined in an auction before the delivery day. Intraday prices arise from subsequent trading closer to delivery and allow market participants to adjust their positions based on updated forecasts or changing conditions.
When are day-ahead electricity prices published?
The prices are determined and published on the day before physical delivery. They provide a price for each 15-minute delivery interval within the relevant bidding zone.
Why can day-ahead prices become negative?
Negative prices can occur when electricity supply exceeds demand and inflexible generators or subsidised assets continue producing. In such periods, sellers may effectively pay buyers to consume or store electricity.
Can a company purchase electricity directly at the day-ahead price?
Usually not without an appropriate electricity supply, trading, or marketing arrangement. Whether a company benefits from day-ahead price fluctuations depends on its contract and on how wholesale prices are passed through.
Does a negative day-ahead price mean that electricity is free?
No. Grid charges, taxes, levies, supplier margins, and other price components may still apply. The actual cost depends on the customer’s contract and applicable regulatory framework.