The words of the electricity market
The terms that appear across the site, explained with their practical consequence — why a country has several prices, why an average is weighted by duration, why a negative price is not a mistake.
Day-ahead market
The auction where electricity for the next day is sold.
Every day, up to a fixed hour, generators say how much they are willing to sell and at what price, and suppliers say how much they want to buy. Where the two curves cross, a price emerges for each interval of the following day. It is Europe's most transparent electricity market, because the result is published in full. The rest of the trade — long-term contracts, the intraday market, balancing — does not have the same visibility.
Bidding zone
The territory within which electricity has a single price.
Inside a bidding zone, electricity is traded as if the grid within it were unlimited: it does not matter which end it comes from, the price is the same. The zone borders follow the places where the grid really is tight. That is why Italy has seven zones and Norway five, while Germany and Luxembourg share one between them. A country is not a zone, and confusing the two produces figures that describe no contract at all.
See: Prices by zone
EUR/MWh and EUR/kWh
The same figure, divided by a thousand.
The wholesale market counts in megawatt-hours; a household bill, in kilowatt-hours. 100 EUR/MWh means 0.10 EUR/kWh. The difference between that figure and what a consumer pays is not the conversion, but everything added on top: the distribution tariff, the transmission tariff, levies, excise duty, VAT and the supplier's margin. In many countries the energy component is under half the bill.
Negative price
You are paid to consume. It happens often.
When wind and sun generate heavily while plants that cannot stop quickly keep running, supply exceeds demand and the price falls below zero: whoever consumes is paid to do so. It is not a data error and it is not rare — Germany saw quotes below −18 EUR/MWh in September 2026. On this site negative prices are shown as they are, neither filtered nor clipped to zero.
MTU — the settlement interval
The unit of time a price is made for.
Until 30 September 2025, the European market worked in hours: a day had 24 prices. From 1 October 2025 it works in quarter-hours, so a day has 96. The consequence for any average crossing that boundary: the intervals have to be weighted by their duration. A plain arithmetic mean would give a quarter of an hour the same weight as an hour, quadrupling the contribution of recent days.
Duration-weighted average
Each interval weighs as much as it lasts.
A day's average is not the sum of the prices divided by their count, but the sum of the prices multiplied by each one's duration, divided by the total duration. When every interval has the same length, the two coincide. When they do not — at the 2025 move from hourly to quarter-hourly, or on a day with gaps — they differ. For Romania, 1 October 2025 gives 124.05 EUR/MWh weighted and 124.56 unweighted.
ENTSO-E
The association of Europe's transmission system operators.
It brings together the system operators — those who run the high-voltage grids — of more than thirty countries. European regulation obliges them to publish operational data, and ENTSO-E gathers it on a shared platform: demand, generation by source, cross-border exchanges, day-ahead prices, outages. It is this site's primary source.
See: Data sources
TSO — the transmission system operator
Who keeps the high-voltage grid in balance.
In every second, what is generated must equal what is consumed, otherwise the grid frequency drifts and equipment disconnects. The transmission operator maintains that balance and runs the high-power lines. In Romania it is Transelectrica; in Germany there are four; in France, RTE.
EIC code
A zone's official name, in 16 characters.
A unique identifier ENTSO-E assigns to every zone, every control area and every market participant. Romania is 10YRO-TEL------P. The codes are neither translated nor abbreviated: they are the key the data is requested with, and the only way to be certain which zone is meant.
Interconnector
The line electricity crosses from one country to another.
It may be an overhead line across a border or a subsea cable hundreds of kilometres long. Its capacity is limited, and when it is full the prices on the two sides part company — that is where the large differences between neighbouring zones come from. Note: being neighbours on the map and being interconnected are not the same thing. Norway and the Netherlands do not touch, yet have a cable; DK1 and DK2 touch and have no direct link.
Import and export
A country's exchange balance at a given moment.
A country imports when it consumes more than it generates and exports when it generates more. The figure changes from hour to hour and, in many countries, in both directions within the same day. On this site the balance is computed from the physical flows measured at the border, not from the difference between generation and demand — the two do not coincide, because the grid has losses.
Renewable share
How much of current generation comes from renewable sources.
It is the ratio of generation from wind, solar, hydro, biomass and geothermal to total generation at that moment. It is not the same as “how much of demand is renewable”: a country that imports heavily has a real mix different from what it generates at home. And it is not an annual average — at midday, in sunshine, the share can be twice what it is at night.
Carbon intensity
How many grams of CO₂ per kilowatt-hour generated.
It is obtained by multiplying each source's generation by an emission factor and dividing by the total. It is an ESTIMATE, not a measurement: the factors are life-cycle averages, and a new gas plant emits less than an old one. On this site the figure is labelled as an estimate everywhere it appears, and the factors used are published.
See: Methodology
Price spread between zones
How far apart two zones are, in euros.
If two well-connected zones have different prices, energy flows from cheap to expensive until they equalise — that is what European market coupling does. When the difference persists, it means the line between them is full or missing. That is why a large spread is a measure of congestion, not an opportunity for profit: it is precisely the impossibility of exploiting it that keeps it there.
See: The biggest spreads
Wholesale price
The exchange price, before everything that is added on.
Every price figure on this site is wholesale. On top of it, a consumer pays the distribution tariff (the low-voltage network in the neighbourhood), the transmission tariff (the high-voltage lines), levies and support schemes, excise duty, VAT and the supplier's margin. The site's tools all compute the energy component, and say so next to every result.
See: The tools