ACER calls for balanced assumptions on market flexibility and national energy targets in Spain’s National Resource Adequacy Assessment
ACER calls for balanced assumptions on market flexibility and national energy targets in Spain’s National Resource Adequacy Assessment
What is it about?
Today, ACER releases its Opinion on Spain’s National Resource Adequacy Assessment (NRAA). This national assessment complements the European Resource Adequacy Assessment (ERAA) 2024, reflecting recent developments in the country’s electricity system, including the integration of the Balearic Islands and Ceuta.
What is a resource adequacy assessment?
The European Resource Adequacy Assessment (ERAA) evaluates electricity resource adequacy across the EU and provides a consistent framework to assess whether additional national measures are needed to ensure security of supply. ERAA is carried out annually by the European Network of Transmission System Operators for Electricity (ENTSO-E) and reviewed by ACER.
Member States can complement the European analysis through national assessments (NRAAs). While based on the ERAA methodology, NRAAs may capture new developments or national specificities not yet reflected in the latest ERAA.
When a national assessment identifies new adequacy concerns, and the Member State informs ACER, ACER must issue an Opinion on the differences between the national and European assessments.
What did ACER find?
Overall, ACER finds the Spanish assessment clear, robust and well executed and notes that most differences with the ERAA 2024 are justified by national specificities and local factors.
Spain’s assessment shows higher electricity adequacy risks for 2030. While results for 2028 are in line with the European assessment, the NRAA estimates that by 2030 the country could experience periods when electricity demand exceeds available supply for more than two hours per year, above the national reliability standard that sets the target level of supply adequacy.
These higher projected risks are linked to two differences identified by ACER between the Spanish NRAA and the ERAA 2024:
- Lower storage capacity: The NRAA assumes that only storage projects already planned or under development will materialise. As a result, Spain would have around half the storage capacity estimated in the ERAA for 2030, limiting the system’s ability to balance variable renewable generation and meet peak demand.
- Stricter gas generation assumptions: Spain’s assessment applies lower generation availability for gas turbine fleet based on historical data, including fixed maintenance schedules. This reduces the generation capacity expected to be available during periods of high demand.
ACER finds the assumptions of lower storage capacity and fixed gas turbine maintenance insufficiently motivated for 2030, as they could better reflect the expected evolution of the electricity system. However, their impact on the overall results of the NRAA is limited, as the modelling approach used (based on a resource expansion calculation) tends to compensate for the missing storage capacity.
What are the next steps?
ACER encourages the Spanish authorities to take its findings into account as the assessment process progresses.