title: "HVDC Regulation - NC HVDC" type: wiki primary_source: eur-2016-1447-hvdc updated: 2026-04-11 tags: [eu-retained, hvdc, interconnectors, offshore-wind, converter-stations, neso]

HVDC Regulation

Commission Regulation (EU) 2016/1447 (NC HVDC) establishes the technical requirements for connecting high voltage direct current (HVDC) systems and DC-connected power park modules (DC-PPMs) to the GB transmission and distribution networks. It is retained EU law, operative under the European Union (Withdrawal) Act 2018 and maintained on legislation.gov.uk.

Primary source: eur-2016-1447-hvdc.md

What it is

NC HVDC is one of three EU-origin grid connection network codes retained in GB law, alongside RfG (Regulation (EU) 2016/631) and DCC (Regulation (EU) 2016/1388). It covers two categories of asset:

HVDC systems: the DC link itself - converter stations, cables, and control systems. This includes interconnectors between GB and continental Europe, back-to-back DC conversion schemes, and embedded DC links within the GB transmission network.

DC-connected power park modules (DC-PPMs): generation assets (principally large offshore wind farms) that reach the AC grid via an HVDC export cable rather than a direct AC connection.

The regulation has 8 Titles, 86 Articles, and 8 technical Annexes. The relevant TSO for GB is NESO; the regulatory authority is Ofgem.

Scope

Article 3 defines four categories of HVDC system within scope:

1. HVDC systems connecting synchronous areas or control areas, including back-to-back schemes (interconnectors)
2. HVDC systems connecting power park modules to transmission or distribution networks (offshore wind export cables)
3. Embedded HVDC systems within one control area at transmission level
4. Embedded HVDC systems at distribution level where cross-border impact can be demonstrated

DC-PPMs are brought into scope by Article 38, which imports and adapts the requirements of RfG Arts 13-22.

Out of scope: HVDC systems below 110 kV (unless cross-border impact), and systems connected to island networks not operating synchronously with GB.

TSO-owned carve-out (Art 3(3)): Where the TSO owns at least one converter station, or the entity controlling the HVDC system also controls the TSO, Articles 11-54 do not apply. This means the full compliance regime primarily targets third-party interconnector and offshore wind developers, not NESO-controlled internal network assets.

Key technical thresholds

HVDC systems

DC-connected power park modules

How it interacts with RfG - dual compliance for offshore wind

Article 38 is the critical interface provision. It states that RfG Arts 13-22 (the technical performance requirements for offshore power park modules under RfG) apply to DC-connected PPMs under NC HVDC, subject to the specific adaptations in Arts 41-45 of NC HVDC.

This creates dual compliance for large offshore wind projects connecting via HVDC:

• As a generating unit, the project must satisfy RfG (type B, C, or D depending on capacity)
• As a DC-connected PPM with an HVDC interface point, it must also satisfy NC HVDC Title III

The adaptations in Arts 41-45 address synchronisation voltage limits (5% cap), protection priority alignment with RfG Art 14(5), and system management requirements from RfG Arts 14(5), 15(6), and 16(4). NESO coordinates both compliance streams.

In practice: Hornsea, Dogger Bank, and future multi-gigawatt offshore wind projects face both RfG and NC HVDC compliance obligations simultaneously. The compliance testing and simulation requirements in NC HVDC Title VI apply on top of the RfG compliance process.

GB interconnector portfolio

All current GB interconnectors are within scope as HVDC systems. Connection requirements apply; existing systems are generally exempt from most provisions under Art 4(1) unless substantially modified (though Arts 26, 31, 33 apply regardless).

New interconnector projects (e.g. proposed links to Germany, Ireland, or further Nordic connections) will face the full NC HVDC compliance regime as new HVDC systems.

Derogation mechanism for radial DC-PPMs

Title VII (Arts 77-83) sets out the derogation framework. The general process requires a cost-benefit analysis and cross-border trade impact assessment.

Article 81 - simplified derogation for radial DC-PPMs: Where a DC-connected PPM connects to a single synchronous area via a single radial connection, no cost-benefit analysis and no cross-border trade impact assessment are required. The rationale is that requirements designed for future meshed multi-area DC grids (which do not currently exist at scale) should not impose disproportionate burdens on single-area radial projects.

Key features of the simplified process: - Available to owners of DC-PPMs with one radial HVDC connection to one synchronous area - Can be applied for early, before final investment decisions, to provide regulatory certainty - Regulatory authority decision within 6 months (extendable by 3 months) per Art 79(7) - Derogation register maintained by regulatory authority per Art 82

For large offshore wind projects in GB with a dedicated HVDC export cable connecting solely to the GB synchronous area, Art 81 is the default route for obtaining derogations from requirements that would only be necessary in a meshed multi-area offshore grid scenario.