Ancillary services

The impact of ancillary services on the average final price of energy was 4.26 €/MWh, higher than the 2.54 €/MWh of 2020. This increase was due to the high prices registered in all markets. If we compare the impact of this service in the final average price, we can see that this year's price was reduced (3.6 % compared to 6.3 % the previous year).

In April 2020, ancillary services accounted for 20 % of the average final price of energy, when they are usually below 5 %. The exceptional situation in the operation of the system due to COVID-19 led to a greater need for the use of ancillary services. In February 2021, the month with the highest percentage of renewables during the year, its weight is the highest this year.

Weight of the impact of the ancillary services on the final price

In 2021, the cost of the ancillary services was 1,032 million euros, 71.7 % higher than in the previous year.

Cost of ancillary services (euro million)

€/MWh€

The energy needs managed through the ancillary services in 2021 were 5.8 % higher than in the previous year. Energy scheduled for security reasons was 6.2 % lower, as a result of the decrease in energy for technical constraints of the Daily Base Operating Schedule (PDBF), which stood at 19.4 %, while the energy for real-time technical constraints doubled. Balancing energy increased by 21.4 %, mainly as a result of the increase in secondary control power and the coming into force at the end of 2020 of the International Grid Control Cooperation (IGCC - imbalance netting process that avoids the need for secondary control power).

The volume of energy for technical constraints of the Daily Base Operating Schedule represented 38.9 % of the total, a percentage that is lower than the value of 51 % registered the previous year.

Energy requirements covered through ancillary services

GWh

The average weighted prices of ancillary services in 2021 were:

Average weighted prices of ancillary services

€/MWh