'Real-time pricing' sounds like financial trading — complicated, opaque, and best left to professionals. In practice, the mechanics are more elegant than they appear. Understanding how electricity is priced in real time demystifies the whole system, and once you see it clearly, the commercial logic of dynamic tariffs becomes obvious.
The Wholesale Market: Where Price is Born
Electricity in Belgium and across interconnected European markets is traded on wholesale exchanges. The most important of these is EPEX Spot, which operates both a day-ahead market and an intraday market.
In the day-ahead market, generators (wind farms, nuclear plants, gas peakers, solar parks) and large buyers submit bids and offers for each hour of the following day. The market clears at the point where supply meets demand, setting a price for each hourly block. This is published by around noon for the following day.
The intraday market then allows participants to trade right up to close to real time — adjusting positions as weather forecasts change, demand shifts, or generation assets go offline unexpectedly.
The price that emerges from this process — the spot price — is the truest reflection of what electricity actually costs to produce and deliver at any given moment.
How That Price Reaches You
With a conventional fixed tariff, your supplier buys energy in advance (often months ahead), hedges their price risk, adds their margin and network costs, and presents you with a single per-kWh rate. The wholesale volatility is absorbed — by them, at your expense.
With a dynamic tariff, the hourly spot price is passed directly to your bill. You pay the EPEX price for each hour, plus a transparent fixed service fee that covers the supplier's costs. There is no hidden spread between what they bought it for and what they sell it to you at.
In practice, your bill is calculated by multiplying your actual consumption in each hourly period by the price that prevailed in that period. Modern smart meters (digital meters, as they are known in Belgium) record consumption at 15-minute intervals, making this granular billing entirely feasible.
The Role of Network Costs and Taxes
It is worth being clear: the wholesale price is only one component of your electricity bill. Distribution network tariffs, transmission costs, various levies, and VAT all sit on top. These are generally fixed or determined by regulation — they do not fluctuate with the spot market.
This means the volatility in your dynamic bill is driven by the commodity component only — typically 30-50% of the total bill for most consumers. The rest is fixed. This is important context when assessing potential savings: you are optimising against a meaningful portion of your costs, not the entirety.
Price Formation in Practice
Electricity prices are highest when demand is high and supply is tight — typically weekday mornings and evenings, cold winter days, periods of low wind and cloud cover. They are lowest when demand is low and renewable generation is high — overnight, weekends, and during strong wind events.
In recent years, the rapid expansion of solar across Europe has created a notable midday price dip on sunny days, as solar floods the grid. Wind events in Belgium, the Netherlands, and northern Germany regularly drive prices close to zero — or even negative. These are not edge cases. They are recurring patterns that a well-managed dynamic tariff strategy can systematically exploit.