FlexSource - ENTSO-E FCR Technical Requirements Nordic (2023)

Source - ENTSO-E FCR Technical Requirements Nordic (2023)


Joint Nordic TSO document specifying the technical requirements for entities providing Frequency Containment Reserve (FCR-N and FCR-D) in the Nordic synchronous area. Published 26 May 2023; valid from 1 September 2023 (Norway from 1 January 2024). Covers prequalification, technical performance standards, measurement, testing, and data/telemetry requirements.

Document metadata

  • Title: Technical Requirements for Frequency Containment Reserve Provision in the Nordic Synchronous Area
  • Issuing body: Joint Nordic TSOs (Fingrid, Energinet, Statnett, Svenska kraftnät)
  • Date: 26 May 2023
  • Valid from: 1 September 2023 (Norway: 1 January 2024)
  • Raw file: Raw/PDF extractions/(entso-e) fcr-technical-requirements-may-23/

Scope

Defines mandatory technical requirements for all FCR providers in the Nordic synchronous area (Sweden, Finland, Denmark, Norway). Applies to FCR-N (frequency containment for normal operation) and FCR-D (for disturbances). Covers individual entities, aggregated resources, and centrally controlled portfolios.

Nordic system parameters

ParameterValue
FCR-N total Nordic requirement600 MW (symmetric, ±300 MW)
FCR-D total Nordic requirement1,450 MW per direction
Nordic nominal inertia (performance)~42,000 MW (ROCOF basis)
Nordic nominal inertia (stability)~23,000 MW
Max single point of failure per entity70 MW each direction
Combined FCR-N + FCR-D per entity100 MW each direction
FCR-N activation range±0.1 Hz from 50 Hz
FCR-D activation range±0.4 Hz from 50 Hz

Prequalification (§2)

  • Validity: 5 years from approval; reassessment simplified if entity configuration unchanged
  • TSO review period: 8 weeks from complete application
  • Approval decision: TSO must decide within 3 months; default approval if no decision
  • Testing must be done by accredited body or agreed test facility
  • Reassessment triggers: hardware changes, change in FCR capacity ≥20%, change in control parameters outside prequalified range
  • Test data must be submitted in standardized csv format (§6.2.1) and stored for ≥14 days operationally
  • TSO can grant exceptions from specific requirements if: no impact on FCR provision capability and no significant impact on system stability or market

FCR-N technical requirements (§3.1–§3.4)

  • Full activation: ≥100% of contracted capacity at ±0.1 Hz deviation
  • Step test performance: 5 min per step (±0.1 Hz); 15-min endurance test; under-delivery max −5%; over-delivery max +20%
  • Capacity reduction factors: dynamic minimum 0.9; static FCR-N: symmetric linear droop within ±0.1 Hz
  • Linearity: response must be proportional across the ±0.1 Hz range for continuously controlled entities; non-continuously controlled entities must meet linearity via step tests

FCR-D technical requirements (§3.5–§3.8)

  • Ramp test — dynamic activation:
    • ROCOF trigger: 0.24 Hz/s
    • At 7.5 seconds after activation: ≥86% of steady-state capacity (Req 2)
    • Energy delivered ≥3.2 s × ΔPss during initial 7.5 s (Req 3)
  • Capacity reduction factors: dynamic minimum 0.75; static minimum 0.84
  • Static FCR-D: max 2.5 s activation delay; 15-min grace period for re-readiness after full activation; deactivation rate ≤2.5%/s; overshoot max 20%
  • Mode shifting: high-performance mode ≤10 s activation, then blocked 5–15 min; high stability mode must pass Nyquist stability criterion

Nyquist stability criterion (§3.9)

A core Nordic FCR requirement — all FCR providers must satisfy:

  • Radius: keep Nyquist curve outside circle of radius 0.43 centered on (−1, 0j)
  • 95% margin variant: TSO may allow the 95th-percentile Nyquist plot to meet the criterion (5% exceedance allowed)
  • FCR-N alternative: 75% margin with explicit TSO exemption
  • Entities using high stability mode for FCR-D must demonstrate Nyquist compliance in that mode

Limited Energy Resources — LER (§3.10)

Entities with less than full-activation endurance (batteries being the primary case):

ParameterFCR-NFCR-D
Threshold for LER classification<2 hours endurance at full activation<2 hours endurance
Minimum endurance before NEM activation60 min (FCR-N)20 min total (5 + 15 min)
Opposite-direction reserve required±34% of FCR capacity20% opposite direction
NEM activation trigger (remaining endurance)<30 min<20 min
Maximum NEM recharging rate34% of contracted capacity (TSO may allow up to 50%)
AEM activation triggerSOC < 5/60 × C/E ratio threshold
AEM reporting5-min rolling average frequency reference; entity declared unavailable

NEM (Normal Energy Management): voluntary recharging mode within LER rules; entity reduces FCR delivery to recharge energy storage. AEM (Absolute Energy Management): entity no longer able to deliver FCR; declared unavailable; TSO notified.

Aggregated resources (§3.11)

Allows small units to qualify for FCR without individual prequalification of each unit:

Type qualification

  • Units ≤100 kW each may qualify via a type certificate (standardized test of one representative unit)
  • Type certificate is technology- and model-specific; extends to all identical units

Dynamic prequalification (capacity extension)

  • A prequalified entity may extend its contracted capacity by up to 25% or 1 MW (whichever is larger), maximum 3 MW extension in total, by adding new units of the same prequalified type without re-running full tests
  • Extension is subject to TSO approval

Dynamic operation

  • Aggregated entities may operate between 80% and 100% of their tested/prequalified configuration
  • This allows for partial unavailability within the portfolio without triggering non-compliance
  • Stand-alone units: different rules apply (no partial range allowed)

Centrally controlled FCR (§3.12)

Requirements for entities that deliver FCR via central control system:

  • Availability of central control: ≥99.95% (equivalent to <4.4 hours downtime/year)
  • Redundancy: either fully redundant central system or local fallback (each unit must be able to deliver FCR autonomously in fallback mode)
  • Volume limit: max 70 MW per single point of failure (same as the per-entity limit)
  • Frequency measurement: must be performed within the LFC (Load Frequency Control) area where the FCR is contracted; cross-area measurement not allowed for control purposes

Measurement requirements (§4)

CapacityPower accuracyFrequency accuracy
<1 MW±5% of prequalified capacity±10 mHz
1–10 MW±1% of prequalified capacity±10 mHz
≥10 MW±0.5% of prequalified capacity±10 mHz
  • Resolution: 0.01 MW (power); 5 mHz (frequency)
  • Sampling rate for tests: 10 Hz for FCR-D tests; 5 Hz for FCR-N tests
  • Operational logging: ≥1 Hz; time-stamped to CET/UTC; stored for ≥14 days

Testing framework (§5)

Required test conditions (4 operational points)

All FCR providers must test at:

  1. High load, high droop (lowest regulating strength, highest load)
  2. High load, low droop (highest regulating strength, highest load)
  3. Low load, high droop (lowest regulating strength, lowest load)
  4. Low load, low droop (highest regulating strength, lowest load)

Tests apply to: FCR-N step tests (including endurance), FCR-D ramp tests (including endurance), FCR-N/FCR-D linearity tests.

Exemptions

  • Single power setpoint: tests 3 and 4 may be omitted
  • Single droop setting: tests 2 and 4 may be omitted
  • Batteries specifically: power setpoint typically does not influence FCR capability — testing at a single setpoint is sufficient (subject to TSO approval)
  • TSO may grant further exemptions based on technology knowledge from prior tests

Capacity range extension

  • If steady-state response depends on ambient conditions (e.g., head for hydro), provider may extend prequalified capacity by up to 25% in each direction vs. tested capacities (subject to TSO approval)

Test reporting

  • Test report plus 1 hour of logged operational data (FCR-N or FCR-D at maximum capacity) to be submitted per entity tested
  • Data in standardized csv format per §6.2.1 naming convention

Data and telemetry (§6)

Three tiers:

  1. Test data (mandatory, submitted during prequalification)
  2. Operational logging (provider stores ≥14 days, delivers to TSO within 5 working days of request)
  3. Real-time telemetry (TSO may require; includes capacity, status, regulating strength per product)

Portfolio-level real-time telemetry (if required by TSO):

  • Total maintained FCR-N/FCR-D capacity (static + dynamic + LER + non-LER)
  • LER-specific capacity per product direction
  • Static FCR-D capacity

Key signals: instantaneous active power [MW], grid frequency [Hz], maintained capacity per product, FCR status (on/off), regulating strength [MW/Hz], power baseline. LER-specific signals: remaining endurance [min] per direction, NEM power [MW], AEM status.

Data file naming: [Resource]_[Service]_[TestType]_[Area]_[Timezone]_[Interval]_[SamplingRate]_[Date].csv

Validity (§7)

Valid from 1 September 2023. In Norway from 1 January 2024. Exceptions may be granted by the reserve connecting TSO if technical or significant economic reasons apply, with no impact on FCR provision or system stability.

Relevance to wiki topics

  • Balancing Markets: defines the Nordic FCR system sizing (600 MW FCR-N, 1,450 MW FCR-D), Nyquist stability framework, and the qualification pathways that determine who can enter the FCR market
  • Energy Storage: LER framework (batteries the primary case), NEM/AEM thresholds (30/20 min remaining endurance), 34%/50% recharging rate limits, SOC-based AEM threshold; 99.95% availability requirement for central control systems
  • Aggregation: type qualification pathway (≤100 kW units), dynamic prequalification (25%/1 MW/3 MW extension rules), dynamic operation (80–100% of tested config) — key enablers for small-unit aggregation into FCR
  • Svenska kraftnät: as the Swedish reserve-connecting TSO, Svk applies these requirements in its BSP prequalification process (linked to Source - Svk BSP Avtal 5937-2 (2025))