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Highest renewable generation in any May on record - Electricity generation and electricity trading in May 2021

8 June 2021 - Electricity consumption and electricity generation in May were up 6.4% and 12.6% respectively compared with May 2020. Generation from renewable energy sources was the highest in any May on record. The average wholesale price was more than three times as high as in May 2020, and Germany was a net importer for the first time this year.

Electricity consumption in May 2020 had been 37.1 terawatt hours (TWh) and the lowest since at least 2015. This was due to the measures to contain the Covid-19 pandemic. Consumption in May 2021 was 6.4% higher and nearly the same as before 2020.

Electricity generation this May totalled 39.4 TWh, around 12.6% higher than in May 2020 (35.0 TWh). Renewable and conventional generation recorded nearly the same year-on-year increase (12.56%/12.62%).

Highest renewable generation in any May on record

Total generation from renewable sources was a new record high: 21.3 TWh was the highest in any May. The two storms Eugen and Marco in Germany at the beginning of the month and at Pentecost were contributing factors. Onshore wind generation was the highest in any May (8.8 TWh). Sunny spells also led to a high level of solar photovoltaic (PV) generation (5.9 TWh).
Renewables made up 54% of generation and covered 54% of consumption (grid load).

Renewable generation in the months of May


Renewable generation


14.230 GWh


16.219 GWh


15.886 GWh


18.377 GWh


18.438 GWh


18.878 GWh


21.248 GWh

Electricity generation from renewable energy sources reached its highest hourly level of 65.4 gigawatt hours (GWh) on Wednesday 5 May between 1pm and 2pm and covered 95.9% of the electricity consumption (68.2 GWh) during this hour. Total electricity generation was 83.7 GWh and net exports* totalled 14.5 GWh. The highest hourly net exports* in May of around 15.2 GWh were recorded one hour earlier.

Average wholesale price more than three times as high

The average wholesale price was 53.35 euros per megawatt hour (MWh) and more than three times as high as in May 2020 (€17.60/MWh). A similar year-on-year increase was recorded in April. The increase in May is due to a higher electricity consumption as well as some high prices.

The hourly products on the EPEX Spot day-ahead market were traded at between negative €69.00/MWh and €101.82/MWh. There was only a slight change in the number of negative wholesale electricity prices: negative prices were recorded in 36 to 38 of the 744 hours of trading this May.

Wholesale prices in Germany

May 2021

May 2020

Average [€/MWh]



Minimum [€/MWh]



Maximum [€/MWh]



Number of hours with negative prices



Number of hours with prices >100 €/MWh



Data basis: smard.de

The highest price on the exchange of €101.82/MWh was recorded on Wednesday 19 May between 8am and 9am, when an electricity consumption of 64 GWh coincided with a low level of renewable generation (19.5 GWh) and a high level of conventional generation (34.3 GWh).

The lowest price of negative €69.00/MWh was recorded on Saturday 22 May between 2pm and 3pm. During this hour, renewable generation was 54.1 GWh and higher than the electricity consumption (grid load) of 52.3 GWh. Net exports* totalled 13.7 GWh.

The chart shows the actual figures for generation and consumption and the wholesale prices on 22 May 2021.

Marked changes in commercial foreign trade

Germany imported 282.6 GWh more electricity than it exported in May, making it a net importer for the first time this year. Net imports were considerably lower than in May 2020, when they totalled 2,079 GWh.

The main customers for German electricity in May 2021 were:
1.    Austria, with 375.9 GWh (down 57.7% from May 2020);
2.    Luxembourg, with 303.0 GWh (up 5.1% from May 2020);
3.    Czechia, with 289.9 GWh (up 36.3% from May 2020).

Germany was a net importer of electricity from:
1.    Denmark, with 331.5 GWh (down 29.2% from May 2020);
2.    Norway, with 243.1 GWh (full trading has only been possible this year);
3.    France, with 232.9 GWh (down 83.2% from May 2020).

At what point in time electricity is imported or exported does not depend solely on supply and demand in the country in question, but also on the electricity prices in the other countries. There is an interaction between supply and demand across the whole of Europe. Changes in imports and exports can also be the result of price fluctuations and are part of normal market activity.

The transmission capacity available at the national borders also plays a role. For example, trade with Austria will be restricted if there is a high volume of trading that would exceed the physical capacity of the grid. This is due to the congestion management scheme introduced at the border with Austria in 2018 when Austria left the joint bidding zone with Germany and Luxembourg. The ALEGrO and NordLink interconnectors provide additional transmission capacity and have enabled full trading with Belgium since November 2020 and full trading with Norway since April 2021.
Trade with Belgium in May 2021 resulted in net exports of 17.2 GWh. Trade with Norway resulted in net imports of 243.1 GWh.