Network Code on High Voltage Direct Current Connections (HVDC)
- Category: Energy Market
Network Code on High Voltage Direct Current Connections (HVDC) means the Commission Regulation (EU) 2016/1447 of 26 August 2016 establishing a network code on requirements for grid connection of high voltage direct current systems and direct current-connected power park modules, which is binding and directly applicable in all EU Member States.
High-Voltage Direct Current and High-Voltage Alternating Current (HVAC) interconnectors - comparison
Differences between HVDC and High-Voltage Alternating Current (HVAC) interconnectors are particularly visible when calculating benchmarks for cross-zonal capacities, where HVDC interconnectors perform better than the HVAC ones.
ACER/CEER Annual Report on the Results of Monitoring the Internal Electricity and Gas Markets in 2016 (Electricity Wholesale Markets Volume, October 2017, p. 22, 29) underlines that in the case of HVDC interconnectors the cross-zonal capacity is assumed to be equal to the thermal capacity of the interconnector, since HVDC interconnectors are virtually unaffected by the factors that impact available cross-zonal capacity on their HVAC counterparts.
In the case of HVAC interconnectors, there are also other elements limiting the capacity that can be offered to the market.
HVDC interconnectors are not impacted by unscheduled flows (composed of Loop Flows (LFs), along with the unscheduled allocated flows (UAFs)).
HVDC interconnectors, moreover, are usually not considered in the N-1 assessment.
HVDC Network Code, Articles 84 - 86
Amendment of contracts and general terms and conditions
1. Regulatory authorities shall ensure that all relevant clauses in contracts and general terms and conditions relating to the grid connection of new HVDC systems or new DC-connected power park modules are brought into compliance with the requirements of this Regulation.
2. All relevant clauses in contracts and relevant clauses of general terms and conditions relating to the grid connection of existing HVDC systems or existing DC-connected power park modules subject to all or some of the requirements of this Regulation in accordance with paragraph 1 of Article 4 shall be amended in order to comply with the requirements of this Regulation. The relevant clauses shall be amended within three years following the decision of the regulatory authority or Member State as referred to in Article 4(1).
3. Regulatory authorities shall ensure that national agreements between system operators and owners of new or existing HVDC systems and DC-connected power park modules subject to this Regulation and relating to grid connection requirements for HVDC systems and DC-connected power park modules, in particular in national network codes, reflect the requirements set out in this Regulation.
HVDC System or DC-connected power park modules connecting with synchronous areas or control areas not bound by EU legislation
1. Where an HVDC system to which the requirements of this Regulation apply is connecting synchronous areas or control areas, with at least one synchronous area or one control area not falling under the scope of application of Union legislation, the relevant TSO or, where applicable, the HVDC system owner shall endeavour to implement an agreement to ensure that the owners of HVDC systems with no legal obligation to comply with this Regulation also cooperate to fulfil the requirements.
2. If an agreement as referred to in paragraph 1 cannot be implemented, the relevant TSO or, as the case may be, the HVDC system owner concerned shall use all available means to comply with the requirements of this Regulation.
Entry into force
This Regulation shall enter into force on the twentieth day following that of its publication in the Official Journal of the European Union.
Without prejudice to Article 4(2)(b) and Articles 5, 75, 76 and 78 the requirements of this Regulation shall apply from three years after publication.
ENTSO-E non-binding guidance on HVDC
Under Article 75 of the HVDC ENTSO-E has the power to issue non-binding guidance on HVDC (Implementation Guidance Document - IGD).
HVDC Network Code, Article 75
Non-binding guidance on implementation
1. No later than six months after the entry into force of this Regulation, the ENTSO for Electricity shall prepare and thereafter every two years provide non-binding written guidance to its members and other system operators concerning the elements of this Regulation requiring national decisions. The ENTSO for Electricity shall publish this guidance on its website.
2. ENTSO for Electricity shall consult stakeholders when providing non-binding guidance.
3. The non-binding guidance shall explain the technical issues, conditions and interdependencies which need to be considered when complying with the requirements of this Regulation at national level.
The main objective of the implementation guidance is to support system operators in the process of determination on national level of non-exhaustive requirements during the national implementation.
Non-exhaustive requirements are those for which the European level network codes do not contain all the information or parameters necessary to apply the requirements immediately and need further national specifications for its entire application in general on national level or as a site-specific choice.
Non-exhaustive requirements of the HVDC are listed in the ENTSO-E Guidance document for national implementation for network codes on grid connection, Parameters of Non-exhaustive requirements, Draft for consultation 1 July -15 August 2016, 22 June 2016, p. 18 - 24.
Further objectives of the IGDs are:
- to facilitate a common understanding of technical issues specified in the connection network codes, in context of new technologies and new requirements (e.g. synthetic inertia),
- to deliver broader explanations and background information and to illustrate interactions between requirements,
- to recommend coordination/collaboration between network operators (TSO) where either explicitly required by the connection codes or reasonably exercised from a system engineering perspective,
- to give guidance to national specifications for non-exhaustive requirements, and
- to express the need of further harmonisation beyond what is requested by the connection network codes when reasonable from a system engineering perspective (see: Connection Network Codes – Introduction to the public consultation of Implementation Guidance Documents, Introduction, 30 June 2016).