On 18/02/2025, the Doel1 nuclear plant retired from in operation, taking around 450 MW of production away from the running 3 GW of active nuclear plants in a grid delivering a total load of 9,5 GW.
So, the total nuclear production has decreased by ca. 17%, reducing the nuclear part to 28% of the total load.
According to the theory, or rather the dogma, that nuclear power is cheap and thus leads to cheap electricity, we should have clearly seen the impact of the retirement of Doel1 on electricity prices.
Of course, this can’t influence the long-term market quotations (futures) like a CAL2026 (a flat power band across 2026), because the market had already expected or anticipated this withdrawal. Economists will say that it had already been incorporated into the price, and this applies for all futures.
Below, as an illustration, the quotations for the MAY-2025 and FEB-2026 futures over the last 12 months:
Understandable. So, no observable impact on that side. But the short-term market, the day-ahead market (the daily bid prices for the next operational day), is directly impacted by all the submitted bids, thus surely by the volume drop of 450 MW down (cheap claimed) production. This impact can be direct, if the nuclear power plants were bid on the day-ahead market, or indirect by promoting competitors from other markets so that they will be attracted to bid on the day-ahead market. In both cases, the expected effect is a significant decrease in the bid while the demand remains unchanged, thus leading to an noticeable increase of the crossing (so-called equilibrium) price.
Below, the total load across the fortnight around 18/02/2025:
We see that the total remains nearly constant, with some ripple due to the weather and other circumstances, and the clear dip during the weekend (recurrent well-known phenomenon).
Let us now look at the prices on the day-ahead market. The day-ahead market for Belgium (formerly Belpex) is the Epex, where the auctions are closed at 12:00 and the result prices, for each hour of the next day, are published at 13:00.
Now, let us focus on the prices across the fortnight around 18/02/2025. The table below gives these results (from 11/02/2025 to 24/02/2025, thus around 18/02/2025):
We can see that 13 and 14/02 have the highest day-average by far, and that these days and the preceding and following 3 ones showed the highest prices of the whole range (see columns ‘average’ and ‘rank’ on the right side of the table). Even Saturday (15/02) shows much higher figures than the weekdays after the retirement of Doel1. The average of all the days before the retirement of Doel1 is 62% higher than that of all the days after (146 €/MWh vs. 90 €/MWh).
The graph below gives the prices along the day for each date (a different color for each date). The curves related to the days before the retirement of Doel1 are in dashed lines and blue-like colors, while the days after this comeback are in continuous lines and red-like colors.
It is clear that the red-like curves are deeply under the blue-like ones. The prices after the retirement of Doel1 are much lower than before.
Drawing conclusions from just a few days is, of course, open to criticism, but don’t forget that the day-ahead market is a very dynamic market, thus directly influenced by an increase or decrease in bids or asks, so that they can’t be invisible. Furthermore, we have also seen that there was no influence on the futures market. And in last December we had already noticed that the comeback of Doel4 had no impact (or an increase rather than a decrease) on the market price (see previous article for the details).
One would argue that external factors or circumstances influence prices, preventing the retirement of Doel1 from having an impact. This, in fact, recognizes that nuclear is not setting the prices, but rather external factors or circumstances.
Observation must always take precedence over theory, and the observation is that, in the best case, nuclear has no impact on the price of electricity, whether in the short-term or the long-term market.
Nuclear is thus only an ideological choice.
I can already hear the nuclear advocates demonizing me for daring to blaspheme against the dogma. While facing the figures, they might come back with other arguments like being CO2-free (or low CO2) and ensuring independence or security of supply. But both are as flawed as the price dogma. We will see this in another article coming soon.