EPEX SpotPower ExchangeElectricity PriceMerit OrderDay-Ahead

EPEX Spot AT Explained: How the Austrian Power Exchange Works 2026

Christian Werner||7 min read

Summary (TL;DR)

The EPEX Spot AT is the European power exchange where Austrian electricity prices for the next day are set daily at noon. Prices are determined by supply and demand according to the merit-order principle: Cheap renewable energies are used first, more expensive power plants only during high demand. Since October 2025, prices are determined in 15-minute intervals instead of hourly. With a dynamic electricity tariff, Austrian households can directly use these spot market prices and purchase electricity at low prices.

What is the EPEX Spot?

The EPEX SPOT (European Power Exchange) is the central European power exchange based in Paris. It organizes short-term electricity wholesale trading in 17 European countries - including Austria, Germany, France, and Switzerland.

Austria has its own price zone: EPEX Spot AT. The prices determined here apply to the entire Austrian electricity market and form the basis for dynamic electricity tariffs from providers like aWATTar, Tibber, or smartENERGY.

The Difference from Other Exchanges

Unlike the EEX (European Energy Exchange) in Leipzig, where long-term electricity delivery contracts are traded, EPEX Spot focuses on short-term trading: electricity for tomorrow (day-ahead) or even for the next few hours (intraday).

How Are Electricity Prices Formed? The Merit-Order Principle

Price formation at EPEX Spot follows the merit-order principle (order of use). The principle is simple: Power plants are deployed sorted by their production costs - the cheapest first.

The Order of Power Plant Deployment

  • Wind and solar (nearly 0 cents/kWh marginal costs) - always deployed first
  • Hydro and nuclear power (low marginal costs)
  • Lignite and hard coal (medium marginal costs)
  • Natural gas power plants (high marginal costs) - often determine the price
  • Oil and peak load power plants (highest marginal costs)

The crucial point: The electricity price for all providers is determined by the most expensive power plant still needed to meet demand. If there's plenty of wind and solar power, the price drops. If a gas power plant must be switched on, it rises.

Day-Ahead Market: The Daily Auction at Noon

The most important market for consumers is the day-ahead market. Here, the electricity price for the next day is set daily at noon.

How the Auction Works

TimeEvent
Until 12:00Power producers and traders submit their bids
12:00Auction closes, matching algorithm runs
From 12:40Prices for all 96 15-minute periods of the next day are published
From 14:00aWATTar and other providers make prices available
From 15:00Smart home systems can plan consumption for tomorrow

Prices are determined separately for each 15-minute period. So the price can be at 5 cents/kWh at 3:00 AM while rising to 25 cents/kWh at 6:00 PM.

Intraday Market: Short-Term Balancing

Besides the day-ahead market, there's the intraday market for even more short-term trading. Here, electricity quantities can be traded up to 5 minutes before physical delivery.

Difference in Price Formation

While the day-ahead market determines a uniform price for everyone according to the merit-order principle, the intraday market works according to the pay-as-bid method: Everyone pays exactly what they bid. For dynamic electricity tariffs, the day-ahead market is primarily relevant.

15-Minute Pricing Since October 2025

An important milestone: On October 1, 2025, EPEX Spot switched from hourly to 15-minute pricing. Instead of 24 prices per day, there are now 96 prices - one for each 15-minute period.

What Does This Mean for Consumers?

  • More precise price formation: Short price peaks and valleys become visible
  • Better optimization: Smart home systems can control more specifically
  • Fairer billing: You pay more accurately what the electricity actually costs
  • Higher savings potential: Short cheap time windows can be used

Prerequisites are a smart meter with activated 15-minute reading - without this setting, your grid operator cannot correctly assign the data.

Typical Price Patterns at EPEX Spot AT

Electricity prices follow certain patterns that you can use for consumption planning:

Daily Profile

Time PeriodPrice LevelReason
02:00-05:00LowMinimal demand, base load
06:00-09:00RisingMorning peak (households, industry starts)
10:00-14:00Falling to lowPV feed-in at maximum
17:00-20:00PeakEvening peak (cooking, heating, TV)
21:00-01:00FallingDemand decreases

Weekly Profile and Seasonality

  • Weekend: Significantly lower prices (industry is idle)
  • Holidays: Often the cheapest days - sometimes negative prices
  • Summer (April-October): Lower prices due to PV surplus, especially at midday
  • Winter: Higher prices due to heating load, less solar power

Negative Electricity Prices: When You Get Paid for Consuming

With very high wind or solar power and low demand, spot market prices can fall below zero. In 2024/2025, there were already over 300 hours with negative prices in Austria.

When do negative prices occur? Typically on sunny weekends in spring/summer between 10:00 AM and 4:00 PM, or during strong winds at night. With a dynamic electricity tariff and smart home system, you can automatically use these hours for EV charging or water heating.

How You as a Consumer Can Use EPEX Spot Prices

Prerequisites

  • Smart meter with activated 15-minute reading
  • Dynamic electricity tariff (aWATTar, Tibber, smartENERGY, Verbund, etc.)
  • Optional: Smart home system for automatic optimization

Where Can I Find Current Prices?

Several sources offer free access to EPEX Spot AT prices:

SourceURLSpecial Feature
aWATTar Chartsawattar.at/services/chartsClear, no registration
stromliste.atstromliste.at/strompreis/epex-spotPrices for today and tomorrow
APG Market Datamarkt.apg.atOfficial grid operator data
Energy-Chartsenergy-charts.infoHistorical data and analysis

APIs for Smart Home Integration

For automatic control of your energy consumption, free APIs are available:

  • aWATTar API (api.awattar.at/v1/marketdata): Free, fair use principle, ideal for ioBroker/Home Assistant
  • smartENERGY API: 15-minute price data in real-time
  • Spotty Energy API: Optimized specifically for Home Assistant

The aWATTar API provides prices daily from 2:00 PM for the next day - perfect for automatic planning of EV charging or heat pump control.

Frequently Asked Questions About EPEX Spot AT

FAQ

Why are spot market prices so different from end customer prices?
The spot market price is only the energy component. Grid fees (~30%), taxes and levies (~25%), and the provider's margin are added. With an end customer price of 25 cents/kWh, the spot market price often makes up only 8-12 cents.
When are tomorrow's prices published?
The auction takes place daily at noon. From 12:40 PM the official prices are available, from 2:00 PM providers like aWATTar make the data available via their APIs.
Can I benefit from low spot market prices without a dynamic tariff?
Indirectly yes - fixed tariffs also orient themselves to the spot market average. But to benefit from hourly fluctuations, you need a dynamic tariff with smart meter.
Why does Austria have its own price zone?
Until 2018, Austria and Germany formed a common price zone. Due to limited transmission capacity, the zone was separated. Since then, Austria has its own EPEX Spot AT prices, which often lie slightly above German levels.
What happens if the exchange has an outage?
In such cases, the Austrian Power Grid (APG) calculates a reference price as fallback. For end consumers, practically nothing changes - billing continues normally.

Conclusion: Understanding the Power Exchange Means Saving Money

The EPEX Spot AT is the heart of the Austrian electricity market. Those who understand how prices are formed and when they're typically low can save considerably with a dynamic electricity tariff.

The key insights: Prices are set daily at noon for the next day. Lots of wind and sun mean low prices. The evening peak (5-8 PM) is usually most expensive. Since October 2025, 15-minute pricing enables even more precise optimization.

With a smart home energy management system, you can automatically use these price fluctuations - without having to check the exchange daily.

About the Author

Christian Werner is an IT consultant and founder of Werner.Solutions in Graz, Austria. He helps Austrian households and SMEs optimise their energy costs through dynamic electricity tariffs and smart automation — combining IT expertise with practical energy consulting.

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