Source - ACER Decision 05-2025 FNAM Annex I (2025)

ACER Decision 05-2025, Annex I: Type and format of data and the methodology for TSOs’ and DSOs’ flexibility needs analysis. Published 25 July 2025. Full operative text of the FNA Methodology (FNAM) approved by ACER under Article 19e(4) of Regulation (EU) 2019/943. 85 pages.

Bibliographic details

Document structure

The FNAM is organized as 18 articles + 3 annexes:

• Arts. 1–5: Scope, definitions, roles and responsibilities, national implementation timeline, confidentiality
• Arts. 6: Data and analysis requirements (common inputs)
• Arts. 7–10: System flexibility needs (RES integration, ramping, short-term)
• Arts. 11–12: Network flexibility needs (DSO and TSO levels)
• Art. 13: Unavailability of flexible resources due to grid prequalification
• Art. 14: Fine-tuning system needs with network needs
• Art. 15: Market barriers and digitalization evaluation
• Art. 16: Guiding criteria for assessing flexibility sources
• Arts. 17–18: Amendments and language
• Annex 1: TSO input data — type and format (Tables 1–13)
• Annex 2: DSO input data — type and format (Table 15 — the central DSO reporting template)
• Annex 3: Fine-tuning process illustration

Key claims and methodology

Two types of flexibility needs

The FNAM distinguishes:

1. System flexibility needs — needed to adjust to variability of generation and consumption at system level (bidding zone scale):

   • RES integration needs (Art. 8): flexibility to reduce renewable curtailment and achieve RES targets
   • Ramping needs (Art. 9): flexibility to cover expected variation of residual load under perfect forecast conditions
   • Short-term flexibility needs (Art. 10): flexibility to cover unexpected variations (forecast errors, forced outages); overlaps with frequency restoration reserve (FRR) capacity

2. Network flexibility needs — locally- and time-specific; prevent or solve congestion or voltage issues:

   • DSO network needs (Art. 11): assessed by individual DSOs or jointly
   • TSO network needs (Art. 12): transmission-level congestion and RES curtailment

DSO network flexibility needs (Art. 11)

DSOs must quantify upward and downward network flexibility needs per target year as:

• Primary: summation of local maximum values of power (MW) and total energy (MWh) during time blocks for each target year
• Minimum data set: summation of local maximum values of MW and MWh per target year (no time-block breakdown)

Critical limitation (Art. 11.3): if a DSO cannot provide quantitative data, qualitative information may be submitted to the designated authority — but qualitative data cannot be used in the fine-tuning process under Art. 14. This creates a tiered system where quantitative DSOs get their network needs incorporated into system-level assessment; DSOs reporting only qualitative data do not.

DSOs must also provide reasoning including: the regulatory framework, incentives for connecting additional RES/load/storage, and expected contractual means (villkorade avtal or market procurement).

Fine-tuning threshold (Art. 14)

Network needs only trigger re-analysis of system needs if they meet a materiality threshold:

• For fine-tuning RES integration needs with DSO distribution network needs: annual RES curtailment due to distribution constraints must exceed 10% of system-level RES curtailment
• For fine-tuning all system needs due to prequalification limits: maximum hourly unavailability of flexible resources must exceed 10% of installed flexible resource capacity

National implementation timeline (Art. 4)

Sweden’s trilateral agreement (Svk + Energiföretagen + Ei) was signed 25 November 2025 — exactly at the Art. 4 deadline. DSO data was submitted April 7, 2026, within the 10-month window.

Market barrier categories (Art. 15)

The FNAM specifies six formal categories for evaluating market barriers to flexibility. TSOs and DSOs must provide data on each where relevant:

1. Lack of proper legal framework for market access to new entrants and small actors
2. Lack of enablers and incentives to provide flexibility
3. Restrictive requirements to provide balancing services
4. Restrictive requirements to provide congestion management
5. Complex, lengthy, and discriminatory administrative requirements
6. Lack of regulatory incentives to system operators to consider non-wire alternatives

Category 6 is the formal EU taxonomy for the CAPEX bias / lösningsneutralitet problem central to Swedish revenue regulation reform.

DNDP as primary data source (Whereas 22)

“DNDPs might not always be available since Member States may not require them from integrated electricity undertakings with fewer than 100,000 customers or serving small isolated systems. In those cases, the data required for the FNA methodology may be based on other relevant data sources.”

This confirms the DNDP as the default primary source for DSO distribution-level FNA data, with alternative data sources as fallback only.

Guiding criteria (Art. 16)

Article 16 requires DSOs to provide per flexibility need: location (geographic and voltage level), direction (up/down), timeframe including duration and frequency of activation, maximum power required, and economic criteria. This creates the template for what DSOs must know about their own needs — and what is currently unknown in most Swedish DNDPs.

Relevance to existing wiki content

• Flexibility Need Assessment — primary document for this page; closes the “ACER Decision 05-2025 (FNAM) full text” data gap
• Distribution Network Development Plan — DNDP confirmed as primary data source for FNA at distribution level
• Electricity Market Design Reform 2024 — FNAM is secondary legislation under Art. 19e of Regulation 2024/1747
• Flexibility Market — market barrier categories provide formal EU taxonomy for Swedish barriers
• Villkorade Avtal — Art. 11 requires DSOs to report contractual means including flexible connections
• Congestion Management — network flexibility needs definition and fine-tuning process