Came across this tweet by Martien Visser questioned the very high electricity price in the Netherlands just past noon on a summer day translated from Dutch:
Quite remarkable: tomorrow afternoon, July 23rd, in the middle of summer, ‘solar champion the Netherlands’ will have the highest electricity prices in all of Northwestern Europe.
#graphoftheday
Source: http://epexspot.com
It is accompanied by this image showing the prices on the day-ahead electricity market (I colored the borders of the Netherlands in blue):
The Netherlands was forecast to have the highest electricity price (€54/MWh) of Northwestern Europe on July 23 in the 14:00 – 15:00 time slot. For those who looked a bit closer to this image, Austria has an even higher price (€73.10/MWh), but Austria is generally considered a Central European country. Just for those who were wondering.
I can understand what Visser is trying to convey in this tweet. Because the marginal cost pricing system of the spot market, the (day-ahead) prices are generally low in summer because solar production is then at it highest. Especially around noon when there is an abundant production and in countries with a large solar capacity. But now “solar champion” the Netherlands somehow managed to have the highest prices just past noon in the heart of summer?
The next day, there was this follow-up tweet emphasizing this point even more (translated from Dutch):
This is particularly special because this afternoon the Netherlands will be able to generate more than 100% of its own electricity demand from solar and wind power. Source: Energieopwek.
It has this graph of the situation on July 23 on the energieopwek.nl app attached to it:
It was initially not clear what the graph shows exactly. It seems to show renewable electricity production of the Netherlands, but that doesn’t make much sense. There is unfortunately no clear explanation on the website itself.
Looking deeper, Energieopwek (“Energy production”) is an app conceived by Visser. It receives data from weather stations every ten minutes and then calculates how much electricity could be provided by solar and wind.
That makes sense. That is why the second tweet mentions “will be able to generate” and not “generates”. What is shown in that graph is therefore not actual production, but the potential electricity production by solar and wind based on weather data. A pity that this is not stated on their website.
Basically, the graph shows that the potential renewable electricity production (largely solar) was 18 GW in the 14:00 – 15:00 time slot on July 23. From what I understand of the tweet, this is more than the demand.
Sure, but then why the high price when electricity production by solar (and wind) could potentially exceed demand? Shouldn’t the price then be pretty low, maybe even negative? That question was unfortunately not answered in that tweet and also not in its comment section. I now want to make an attempt to explain how this could be possible.
Let’s start on Tuesday July 22. It had been sunny, but there have been (sometimes heavy) showers in the past couple days. The forecast was changeable weather until at least Friday.
Electricity producers need to trade on the day-ahead market what they can provide every hour of the next day. Because the weather at that moment was forecast as changeable, the solar electricity providers were probably not that sure of their production in that time slot. I think that therefore they only bid small volumes and left the rest of the expected demand to be filled in by other providers. These however have higher marginal costs and this will drive up the day-ahead price.
The next day, it is very sunny in the 14:00 – 15:00 time slot and solar (plus wind) energy could potentially produce more than demand. Leading to the situation where there was plentiful of generation after all, but the day-ahead price was set high.
That is what I think is (one of) the reason(s) why “solar champion” the Netherlands ended up with the “highest day-ahead prices in all of Northwestern Europe” during a time when its potential was at its peak.
via Trust, yet verify
July 30, 2025 at 02:45PM
Iowa Climate Science Education 