Flexibility Need Assessment

The Flexibility Need Assessment (FNA; Swedish: Flexibilitetsbehovsbedömning or Flexibilitetsbehovsanalys) is a mandatory biennial process requiring TSOs and DSOs to quantify, report, and aggregate their flexibility needs at national level.

EU legal basis

The FNA is mandated by Art. 19e of Regulation (EU) 2019/943, as amended by Regulation (EU) 2024/1747 (Electricity Market Design Reform 2024). Art. 19e requires each member state to conduct an FNA at least every two years, covering at least the next 5–10 years. Key requirements from Art. 19e:

• Responsible body: the regulatory authority or another designated authority/entity (in Sweden: Svenska kraftnät as Designated Entity, under Ei supervision)
• Methodology: ENTSO-E and EU DSO Entity jointly develop the data type/format and analytical methodology; submitted to ACER for approval
• Methodology submission deadline: ENTSO-E and EU DSO Entity had to submit their joint proposal to ACER by 17 April 2025; ACER then had 3 months from receipt to approve or amend it (so, if submitted on time, a deadline around mid-July 2025) — the methodology was approved by ACER Decision 05-2025 (published 25 July 2025), close to that window rather than “missed by over three months”
• Report contents: seasonal/daily/hourly flexibility needs; demand response and storage potential; market barriers and mitigation; digitalisation contribution; cross-border flexibility potential
• Submission: to Commission and ACER; published; ACER issues cross-border analysis within 12 months

The methodology established by ACER Decision 05-2025 (the FNAM — FNA Methodology) was approved by ACER under Article 19e(4) of Regulation (EU) 2019/943 and published on 25 July 2025; it sets the type and format of data and the methodology that the TSOs and DSOs must follow for the flexibility needs assessment. It is a separate instrument from the NC DR, part of the same regulatory architecture. (Source - ACER Decision 05-2025 FNAM Annex I (2025))

Definition and purpose

Formal definition (Bilaga I): “Med flexibilitetsbehov avses behov av att ändra eller begränsa kunders inmatning och uttag av el.” — The need to change or limit customers’ electricity injection and withdrawal.

Operationally: the summated maximum average hourly power [MW] that must be available to ensure all grid assets stay within a DSO’s operational transfer limits (operationella överföringsgränser), given projected customer connections in a target year and the expected grid structure for that year. (Source - FNA Bilagor I-V (2025-2026))

The FNA provides a structured, harmonized analysis of how much flexibility — at both system level and network level — is required to:

• Integrate increasing volumes of variable renewable generation
• Maintain operational security as electrification increases demand
• Enable faster customer connections without grid reinforcement bottlenecks

Critically, the FNA is a needs description only. It does not determine who procures flexibility, which mechanisms are used, or how costs are allocated. Those questions belong to Flexibility Market rules, Villkorade Avtal, and the broader Network Code on Demand Response market framework. (Source - FNA Överenskommelse Svenskt genomförande 2026 (2025))

Up-regulation and down-regulation

Down-regulation (nedreglering) — DSO needs to: reduce a customer’s injection, enable greater-than-normal withdrawal, or activate a customer to increase withdrawal. Grid situation: too much generation / too little demand locally.

Up-regulation (uppreglering) — DSO needs to: increase a customer’s injection, reduce allowed withdrawal, or activate a customer to reduce withdrawal. Grid situation: too much demand / too little generation locally.

What counts and what doesn’t

Counts: flexibility for N-1 contingencies where customers remain energized. Does not count: events leading to customer disconnection. Explicitly excluded from FNA 2026: voltage regulation needs (methodology not yet mature); SO GL §182 situations (customers constrained due to balancing market participation — §182 agreement not yet in place).

FNA scope vs DNDP scope

The FNA covers a broader set of flexibility needs than the DNDP (Distribution Network Development Plan):

A DSO reporting only its DNDP-identified flexibility in the FNA is likely underreporting. (Source - FNA Bilagor I-V (2025-2026))

Two dimensions

The FNAM (FNA Methodology) distinguishes two types of flexibility need:

Three system flexibility need types (FNAM Arts. 8–10)

The FNAM breaks system flexibility into three indicators, each derived from ERAA/NRAA economic dispatch:

1. RES integration needs (Art. 8): the quantity of flexibility required to reduce renewable curtailment and achieve the member state’s RES target; calculated as the gap between actual curtailment and the RES integration target
2. Ramping needs (Art. 9): flexibility to cover expected variation of the residual load (demand minus non-dispatchable generation), assuming perfect forecast — addresses technical constraints not captured in hourly ERAA modelling
3. Short-term flexibility needs (Art. 10): flexibility to cover unexpected variations from forecast errors and forced outages; the portion covered by frequency restoration reserve (FRR) capacity is already counted and not double-counted

These three indicators are computed at bidding-zone level, then fine-tuned using network needs data where a materiality threshold is met.

DSO network flexibility needs — qualitative data limitation (FNAM Art. 11)

DSOs must quantify their network flexibility needs as MW and MWh per target year. Critical rule: if a DSO cannot provide quantitative data, it may submit qualitative information instead — but qualitative data cannot be used in the fine-tuning process (Art. 11.3). Fine-tuning only occurs when DSO RES curtailment from network constraints exceeds 10% of system-level RES curtailment (or when prequalification limits exceed 10% of installed capacity). DSOs submitting only qualitative data are therefore excluded from the system-level fine-tuning step.

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

Process and outputs

The FNA feeds into a regulatory cascade with specific deadlines:

ACER’s own timeline matches the cascade above: each member state conducts a national FNA “(by July 2026)”, submits it to ACER and the Commission, and uses the findings to define indicative national targets for non-fossil flexibility “(by January 2027)”; ACER then publishes an EU-wide report with cross-border recommendations and a needs-vs-availability gap analysis “(by July 2027)”. (ACER, Flexibility) At ESEC 2026 (6 October 2026) ACER and the Commission discussed whether the assessments are delivering usable investment signals; the framing was that the next challenge is turning them into clear national objectives (Source - ESEC 2026 Policy Session Are the FNAs Working (2026)).

Biennial repetition follows: FNA 2028, FNA 2030, and so on, on the same cascade. FNA results must feed into national Distribution Network Development Plans (DNDPs / nätutvecklingsplaner) — the same data and methods are used for both. (Source - Flexibilitetsbehov FNA Energiföretagen Sverige (web, 2026))

Swedish non-fossil flexibility target — Ei proposes 0 MW. The amended EU Electricity Regulation requires each member state to set an indicative national target for icke-fossil flexibilitet (flexibility provided without fossil fuels — chiefly energy storage and demand response). The government tasked Ei with proposing Sweden’s target; Ei delivered Ei R2026:07 in September 2026, proposing the vägledande (non-binding) target be 0 MW for both 2030 and 2035 — because Sweden’s base-case renewable-generation forecast already exceeds its implied integration target by a wide margin in every year (40 TWh surplus 2030, 23 TWh 2035), a sensitivity high-scenario only narrowly flips to a 4 TWh deficit by 2035. Because the proposed target is 0 MW, Ei does not propose specific demand-response/storage/generation contribution splits, despite the original assignment asking for exactly that. This is Ei’s proposal, not the final decision — the government still decides, expected to feed into Sweden’s NECP update. (Source - Ei R2026-07 Vägledande Mål Icke-fossil Flexibilitet (2026))

Swedish reporting structure

Sweden’s implementation uses the standard TSO-DSO hierarchy:

Geographic granularity: per elhandelsområde (bidding area; SE1–SE4). Data aggregated to highest voltage level (130–220 kV).

The entity that reports the need is the one experiencing the constraint — not necessarily the one obligated to resolve it. If a lokalnät is constrained by its subscription capacity to the overlying regionnät (even if that reflects a bottleneck in the overlying network), the lokalnät reports the flexibility need. This separates the reporting obligation from the procurement obligation; the latter follows the Ei2025:01 rule that the operator whose own network contains the physical constraint bears the obligation to act. (Source - FNA Överenskommelse Svenskt genomförande 2026 (2025))

Report structure and key output questions

The FNA 2026 report (drafted by Svenska kraftnät as Designated Entity) must answer four key questions in its conclusions:

1. What flexibility need does Sweden have to achieve its renewable electricity targets for the next 5–10 years?
2. What potential does non-fossil flexibility have to meet needs at transmission and distribution level?
3. What market barriers exist? How can they be counteracted?
4. How has increased digitalization contributed to the transmission and distribution system?

Questions 3 and 4 are addressed through the market barriers and digitalization evaluation (Bilaga V), which collects structured survey data from DSOs and flexibility providers. Legal basis: Art. 19e of the Electricity Market Regulation (EU) 2019/943 as amended by Regulation 2024/1747 (Source - Electricity Market Design Reform Regulation (EU 2024-1747)). (Source - FNA Bilagor I-V (2025-2026))

Six FNAM barrier categories (from Bilaga V)

The FNAM specifies six categories of market barriers that must be evaluated:

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 — this directly corresponds to the CAPEX bias that Ei‘s TOTEX reform addresses

The survey asks DSOs directly: “Are there sufficient incentives for network companies to consider flexibility solutions as an alternative to building grid?” This will produce Sweden’s first official, systematic answer to the CAPEX bias question from the DSO community itself.

Swedish FNA 2026 — first cycle

Sweden’s first FNA was agreed in an Överenskommelse (tripartite agreement) signed 2025-11-25 by Svenska kraftnät, Ei, and DSO representatives (Vattenfall Eldistribution, E.ON Energidistribution, Göteborg Energi, Ellevio, Kraftringen Nät) via Energiföretagen Sverige.

The agreement adopts minimum requirements for the first cycle, with explicit ambition to expand in FNA 2028. Ei’s own official guidance page for grid companies confirms this trilateral framework and the reporting cycle — biennial from 2026, each covering the coming 5–10 years — and specifies that the national FNA report (compiled by Svk after Ei approval) feeds the national non-fossil flexibility target (Art. 19f, Regulation 2024/1747) and ENTSO-E’s Union-wide Network Development Plan. (Source - Ei FNA Method Page (2025))

Technical scope of FNA 2026

Phase 2 timeline

Key dates from Bilaga IV, updated with actual outcomes now that the cycle has run its course:

(Source - FNA Bilagor I-V (2025-2026), Source - Svk FNA 2026 Slutrapport (2026))

What is deferred to FNA 2028

Four significant data elements were agreed to be deferred from FNA 2026:

1. Contractual means (villkorade avtal vs market-based) — “the regulatory framework is still unclear.” Direct acknowledgment that the Ei2025:01 / Art. 6a ambiguity around Villkorade Avtal has not yet been resolved enough to report procurement pathway data.

2. Guiding criteria (FNAM Art. 16.4) — assessing which existing flexibility resources can meet identified needs requires a flexibility register and full customer visibility that do not yet exist in Sweden.

3. Grid prequalification data (SO GL Art. 182) — the formal TSO-DSO agreement on how flexibility activations are constrained for grid safety was not yet concluded when FNA 2026 was scoped. Update (September 2026): Svk and Energiföretagen have drafted the Art. 182 agreement and Svk put it out for remiss (30 September to 26 October 2026); entry into force is still expected spring 2027 (phased, voluntary for grid companies). It regulates grid prequalification and temporary limits for ancillary services connected to region/lokalnät, but is not final or signed. (Source - Svk Energiföretagen SO GL Art 182 Avtal (2026))

4. Svk transmission network needs — Svenska kraftnät will not report transmission-level flexibility needs in FNA 2026 due to insufficient methodology maturity; deferred to FNA 2028. The first FNA thus covers only distribution-network flexibility needs.

These four deferrals are diagnostic: they map exactly onto the infrastructure that does not yet exist (flex register, SO GL Art. 182 agreement, transmission methodology) and the regulatory ambiguity that is still being resolved (procurement mechanisms).

FNA 2026 results (Svk final report, 29 June 2026)

Svk published the actual FNA 2026 slutrapport (163 pp., ärende 2025/4663) on 29 June 2026. Headline results:

• System-level RES spill rises from ERAA’s raw ~3.43 TWh (2030) to 3.66 TWh (2030) / 5.22 TWh (2035) after DSO-data fine-tuning (only SE3 both years and SE4 2030 cross the 10% materiality threshold). Spill is structural — occurring in over half the year’s hours — not confined to extreme events.
• Existing flexible resources cover ~100% of hourly residual-load variability in 2030 (74% by 2035) but only <20% of daily and ~24–30% of seasonal variability — a persistent duration mismatch between short-acting resources and longer-timescale surplus.
• Under Sweden’s base-case RES target (NEKP: 81%/2030, 82%/2035), the analysis finds zero unmet RES-integration need. Only a sensitivity case using Energimyndigheten’s more ambitious long-term scenario (90%/2030, 95%/2035) produces a gap — ~4 TWh unmet by 2035 — meaning whether Sweden actually “needs” more flexibility resources for RES integration depends entirely on which renewables-ambition trajectory materializes.
• Covering SE3’s full unmet up-ramping need with batteries alone would require ~9× today’s installed Swedish battery capacity — a real capability, technically, but implausible as a single-technology solution at this scale.
• Distribution-network flexibility need: national RES-linked share of down-regulation need is 52% (2030) → 71% (2035); summer down-regulation need roughly doubles 2030→2035, winter up-regulation rises ~1.5×; SE3 largest throughout. This directly answers the “will DSOs populate the nedreglering rows” question below — they did, with substantive, non-zero values.
• Market-barriers survey (91 responses): confirms four now-familiar themes (unclear regulation, weak TSO-DSO-market coordination, weak revenue-cap incentives, short-termism) and states that only two established Swedish local flexibility market programs exist as of this report — E.ON Eldistribution’s 11 markets and Effekthandel Väst’s 2 (Göteborg Energi Nät + Mölndal Energi Nät).
• Next step: Svk’s report names Ei as the responsible authority for setting Sweden’s Art. 19f non-fossil flexibility target, based on these FNA results.

(Source - Svk FNA 2026 Slutrapport (2026))

NC DR Art. 29.1 — the three-way FNA-DNDP-NC DR linkage

NC DR Art. 29.1 requires each system operator at least every two years to perform a biennial assessment of the need for and procurement of DR/storage as alternatives to system expansion. This assessment formally integrates FNA and DNDP:

This is the wiki’s canonical rendering of the linkage; Distribution Network Development Plan and The Regulatory Architecture for Swedish Flexibility 2026–2028 both reference it rather than repeating the diagram.

The assessment must also be publicly consulted. This means the FNA is not a standalone exercise — it is the upstream input that flows into both the NC DR biennial assessment and the DNDP cycle, making the three instruments mutually reinforcing. (Source - FNA Webinar 7 (2026-03-16))

ACER/CEER confirmation: The 2025 ACER/CEER guidance on distribution network planning explicitly states: “DNDPs are the primary source of DSOs’ data and analyses” for the FNA. The guidance also explicitly names Tabell 15 (FNAM Annex 2 data template) as the bridge format — DNDPs should populate the same Tabell 15 template used for FNA reporting. This is the most authoritative confirmation of the DNDP-FNA relationship available. (Source - ACER CEER DNDP Guidance (2025))

Sweden’s comparative position: Sweden is one of only 4 EU countries that have quantified flexibility needs in their DNDPs (alongside Denmark, Portugal, and Slovenia). Sweden’s DNDP first round (2025) specified only one direction, where the other three countries provided both upward and downward estimates — but this is already corrected in FNA 2026, not deferred to FNA 2028 as earlier expected. The Tabell 15 v1.03 reporting template (Bilaga III, dated 2026-03-16) contains obligatory rows for both ↑ uppreglering and ↓ nedreglering, for each target year (2030 and 2035) and each season (Vintersäsong and Sommarsäsong); a value must be entered for both directions even where it is 0. The downward (nedreglering) need is additionally split out via the mandatory Andel av nedregleringsbehov som utgörs av RES-begränsning (MW) column. Both-direction reporting therefore applies from FNA 2026. Portugal is still cited by ACER/CEER as the most advanced country, using probabilistic analysis and cost-benefit comparison of flexibility vs. reinforcement. (Source - ACER CEER DNDP Guidance (2025), Source - FNA Bilagor I-V (2025-2026))

(Note: the template’s predefined season values are spelled “Vintersässong” / “Sommarsässong” — a misspelling in the official Svk/Ei workbook; the correct Swedish is “säsong”.)

Art. 31.1 — flexible connection agreements treated as firm

A critical methodological rule from NC DR Art. 31.1: flexible connection agreements (villkorade avtal) shall be treated as firm connection agreements when assessing flexibility needs. The controllable capacity contracted under a villkorat avtal must be counted as always-available capacity — meaning the DSO must report the full underlying grid constraint, not a number reduced by existing contractual coverage.

This ensures FNA and DNDP figures represent true infrastructure gaps. Only permanent solutions under Art. 6a.1.c are exempted. (Source - FNA Webinar 7 (2026-03-16), Villkorade Avtal)

Relationship to NC DR

The FNA sits within the NC DR implementation architecture but is operational ahead of the main network code:

• ACER Decision 05-2025 (FNAM) was published on 25 July 2025 and sets the methodology the TSOs and DSOs follow for FNA reporting; it is a separate instrument from the NC DR
• The FNA results will inform the flexibility register design (what resources exist to fill the identified gaps)
• The FNA will shape DSO Congestion Management planning and the case for local Flexibility Market development
• The NC DR’s transparency requirements for DSO flexibility procurement and DNDP publication are tightly linked to FNA outputs

Calculation methods

How DSOs actually quantify their flexibility needs — the two-binding-constraint logic (N-1 technical capacity vs. subscription limit to the overlying grid), the probabilistic and AMI-classification tools (Endre, RISE), the what-if and national top-down scenario methods, the Skånes Effektkommission four-step guide, and the Energiforsk lathund as de-facto industry standard — is treated in full at DSO Flexibility Need Calculation Methods. In short: the flexibility need reported is the maximum flexible power that must be available so that all network components stay within the grid’s operational transfer limits (including any N-1 situation, and not the flexibility expected to be available), for the target year in the most likely scenario, split by season, direction and reason, in the FNAM Tabell 15 format. The subscription capacity indication from the overlying network is the critical external input lokalnät cannot assess their need without. (Source - FNA Webinar 7 (2026-03-16))

Swedish coordination

Energiföretagen Sverige‘s AG Helhet Flex task force ran seven preparatory webinars (June 2025 – March 2026) to coordinate DSO participation in the first FNA. Ei has supervisory authority — if Svk and DSOs cannot agree on a methodology decision, Ei decides. (Source - Flexibilitetsbehov FNA Energiföretagen Sverige (web, 2026))

DNDP-aggregated DSO flexibility needs (pre-FNA benchmark)

Ei‘s synthesis of the first round of DNDP submissions (Ei PM2025:03, March 2025) provides the authoritative aggregate of reported Swedish DSO flexibility needs — the best available quantitative pre-FNA picture, distinct from the standardized FNA 2026 output (published July 2026). Coverage: 122–127 companies (of 152 DNDPs reviewed), ~60% of Swedish customers; ~45% of the 155 first-round DNDP submitters reported non-zero needs. (Source - Ei PM2025-03 DNDP Sammanställning (2025), Source - FlexAbility Delrapport 1 (2025))

The wide ranges reflect inconsistent reporting methodology across DSOs — differences in reference years, accumulated vs incremental reporting, and inconsistent load-diversity assumptions create “considerable uncertainty intervals” (Ei) — exactly the comparability problem the FNA 2026 standardization (FNAM Tabell 15) is designed to address.

The per-company DNDP profiles behind these aggregates — including Vattenfall Eldistribution‘s deliberate N/A (no market-based flexibility), Ellevio‘s quantified Tabell 3 needs, E.ON Energidistribution‘s ~700 MW / ~1 TWh county breakdown, GENAB, and the Skåne regional cross-DSO synthesis — are detailed in Swedish DNDP First Round — DSO Profiles (2025-2034). The calculation methods that produced them are at DSO Flexibility Need Calculation Methods.

FNA 2026’s standardized distribution-network need (replaces the PM2025:03 range)

The FNA 2026 final report gives the same underlying DNDP data (~70% of Swedish DSOs) in the FNAM’s own target-year/direction/season/reason structure, rather than a horizon range — the standardization the PM2025:03 ranges above were always meant to be superseded by. Ned (down-regulation) and Upp (up-regulation) are kept separate rather than combined:

SE3 dominates every row (~55% of the 2030 total). Down-regulation need roughly doubles 2030→2035, driven almost entirely by summer solar/wind spill (the RES-spill share of down-regulation need rises from 52% to 71% nationally); up-regulation rises ~1.5×, driven by winter cold-period events. No unmet distribution-level need is reported — DSOs believe existing resources and planned grid investment already cover what they identified. Full per-zone, per-season, per-reason breakdown is on Source - Svk FNA 2026 Slutrapport (2026) (Tabell 23–24).

These figures aren’t directly comparable to the 277–1,030 MW PM2025:03 range above — different horizon convention (fixed target year vs. rolling 0–2/3–5/6–10 year bands) and Ned/Upp are no longer combined into one number — but they are the authoritative current figure for any comparison against actual market-procured flexibility; see Declared vs. Delivered — How Much DNDP Flexibility Need Becomes Procured Flexibility.

Finland’s first FNA cycle (2026)

Finland runs the same FNAM with a different institutional split. Svenska kraftnät compiles Sweden’s report from DSO input collected under a tripartite agreement; in Finland, Fingrid is being designated as the body that compiles the report and also analyses system-level and transmission-grid needs, with Energiavirasto approving it before submission to ACER and the Commission (Source - Energiavirasto Finnish FNA Process Documents (2025-2026)).

Two Finnish design choices stand out. The baseline is the development plan’s future picture, not today’s grid and not a no-investment case, so reported needs are those remaining after the plan’s own assumptions. And the draft excludes demand response from the resources counted, which Energiateollisuus says may overstate the need; a sensitivity case in the draft shows uncovered ramping needs falling to nearly zero with full demand response (Source - Energiateollisuus Statement on Draft Finnish FNA Report (2026)). No Finnish need volumes are public, so the two countries’ results cannot yet be compared in MW.

ACER’s first read of the national FNAs’ barrier sections (October 2026)

At the third Demand Response European Stakeholder Group meeting on 6 October 2026, ACER reported that 13 national FNAs were available to it as of 14 September 2026, Sweden’s among them, and 15 were missing. The barrier chapters range from short qualitative descriptions to detailed analysis, and only Slovenia, Lithuania and Portugal supplied data covering almost all of ACER’s 24 barrier indicators, so ACER found no systematic, comparable picture and plans additional data collection by December 2026, a summary report of the FNAs in January 2027 and a full report on needs and barriers in July 2027. In ACER’s preliminary overview Sweden is flagged for, among others, restrictive prequalification, reliance on flexible connection agreements over local flexibility markets, administrative barriers to local market access and a tariff design that favours grid expansion; the slides contain no quantitative flexibility-need figures (Source - DRESG 3rd Meeting (2026-10-06)).

Data gaps

• The approved Finnish national FNA report and its need volumes (MW and MWh for 2030 and 2035): the draft was consulted on in summer 2026 and approval was expected in July 2026, but neither the draft nor an approval was public as of 5 Oct 2026; would allow a quantitative comparison with the Swedish figures above
• Whether the Energiforsk lathund (2024:1006) will be formally endorsed by Ei or incorporated into EIFS 2026:4 requirements for the 2027–2036 DNDP cycle — not addressed in the FNA 2026 final report (no mention of the lathund found)