(Aerial photo of Lac du Cleuson in Switzerland. Water from the reservoir is often pumped into the Grande Dixence Dam's reservoir, Lac des Dix, for use in hydroelectricity production.)
This April has seen a notably cold spell of weather sweep across Europe. Temperatures have been 4 or 5 degrees Celsius below normal in most areas, whilst spot prices for the past month have delivered 5-7 €/MWh higher than expected in several areas. In this blog post, we study how the Central Western European (CWE) hydropower system developed during this cold spell and compared this situation to available historical statistics.
To understand this year’s scenario, we must first look at the low temperatures which have had a significant impact on the hydropower system in the CWE area. With the expected snowmelt being delayed as a result, energy inflows have been reduced and we now see very low water reservoir levels for this time of year. Consequently, hydropower production declined significantly in most CWE countries during March and April.
- The hydropower production across CWE (AT + FR + DE + CH) for April is at it’s lowest level for 25 years
- Even at individual country level we still see these 25-year lows
- Low hydro-reservoirs for Austria and Switzerland has hampered the production level recently
- Very low inflows in France and reduced run of river production have been significant factors in the lower-than-normal total production level.
- Inflows for the first part of May will remain significantly lower than normal. Production levels will not increase significantly therefore in the next 2 weeks - due to the delayed snowmelt
Production during April 2021 – 25-year statistical comparison
From the chart below, we can clearly see how production levels fell as early as mid-March for France and around mid-April in Switzerland. The low production for France is mainly due to low inflows, while the low Swiss production has been caused by very low reservoir levels. You can read more detail on these issues on Energy Quantified's hydrology webpages.
For April 2021, the production details across CWE are summarized in the following table:
This shows that CWE production is about 4500 MW lower than normal, which is equivalent to somewhere between 4-5 Nuclear blocks. The resulting price-effect for France (using a simplified method) is estimated to be about 3 €/MWh, when compared to years with more normal hydropower levels.
From the chart below, you see the 25-year history of April production for CWE as a whole, alongside the production of France. Year-on-year outputs are well correlated because France is the largest hydropower producer in the CWE area. The 2021 statistics for both are at the lowest observed levels since 1997, when our statistics start. This proves that temperature is a very decisive factor for CWE hydropower output for this time of year.
We can also show some details for the April-inflows and the reservoir-levels, see tables and chart below.
From this, we see the strongly correlated inflow level across CWE. This is probably close to the lowest we’ve seen in 25 years too, but EQ does not have the data available for that entire period yet. Concerning the reservoir levels, the 2021 level is close to what we saw in 2018. This is visible in the chart below, where we show the weekly statistics for the 2015-2021 period.
In this blog we have focused on extremely low hydropower production across the CWE area in April and how this has resulted in higher spot prices in specific areas.
Beyond this, we follow all fundamentals in the European power markets, publishing blog posts explaining notable instances such as this one.
Hydrology also remains an important part of the analysis service from Energy Quantified, enabling us to publish both qualified forecasts - as well as statistics as in this case.
If you have any questions about this blog, or hydrology in general, please get in touch at firstname.lastname@example.org.