Sources: European power exchanges (for Italy: Prezzo Unico Nazionale, or PUN)

Prices rose again across Europe in 2018. Increases were more moderate in France than in neighbouring countries (with the exception of Spain), ending the year up by an average €5/MWh relative to 2017.

Prices were notably higher than in previous years during the summer months, when fuel prices (gas and coal) and the CO₂ price were all up. Moreover, a warm and dry summer in Europe, including a few spells of intense heat, drove up consumption while sharply reducing hydropower generation in Nordic countries. High temperatures also led several European nuclear plants to curb power output due to environmental constraints relating to the temperature of water used to cool reactors (rivers, seawater).

A cold spell that settled across Europe at the end of February also pushed prices up. Prices in France were above €150/MWh on four days in November and hit a high for the year of €259.95/MWh on 21 November at 6:00 pm, when temperatures were below normal for the season. At the same time, the availability of the Belgian nuclear fleet was sharply reduced by extended maintenance in the fourth quarter (of the total 6 GW installed, 2 GW or less was available), putting further stress on the European power system.

Conversely, the number of hours during which prices were negative increased to 11 in France including seven on 1^st January alone. On that day, prices fell as low as -€31.8/MWh, a record low since 2013. Episodes of negative prices are much more frequent and pronounced in Germany, notably because the country’s electricity mix includes more non dispatchable capacities.

Cases of price convergence within the CWE region decreased slightly to 33%, reflecting a wide range of situations. In the week of 30 July, prices converged during 89% of one-hour periods (the highest level in seven years). During some other weeks, when market conditions varied greatly between zones or were stressed, for instance during cold spells, prices did not converge across the region during a single one-hour period.