On the short-term market, the price of electricity supply for the following day in Belgium rose to 408.21 euros per megawatt hour (MWh). Between 8:00 p.m. and 9:00 p.m., it will even be more than 680 euros. In France, we are at 486 euros per MWh, very high prices, especially for a summer day.
The cause is to be found in the heat wave, which puts a high demand on cooling systems, while the weak wind slows down the wind turbines. Gas-fired power plants therefore have to run longer in the evening.
In Belgium, prices are also influenced by France, where many nuclear power plants are broken down or unavailable. The heat also prevents several of them from operating at full capacity: each plant has its own regulatory water discharge temperature limits that must not be exceeded, so as not to heat up the surrounding waterways and protect its fauna and flora. The power plants indeed pump water to cool the reactors, before rejecting it.