IN Brief:
- Elia Group and CPP Investments have acquired the Tarchon interconnector project from Copenhagen Infrastructure Partners.
- The proposed 1.4GW HVDC connection would link the British and German electricity systems.
- Development will continue through regulatory approvals, engineering, financing, and construction preparation.
Elia Group and Canada Pension Plan Investment Board have acquired the Tarchon interconnector project, taking control of a proposed 1.4GW high voltage direct current connection between Britain and Germany.
The project has been acquired from Copenhagen Infrastructure V, a fund managed by Copenhagen Infrastructure Partners. CPP Investments will commit C$1 billion and hold the majority interest, while Elia Group will participate through its international development platform, WindGrid, with an indirect 25% economic interest.
Tarchon is progressing through regulatory processes in Britain and Germany, with the project intended to create a controllable electricity route between two of Europe’s largest power markets. Once operational, the link could support energy trading, system balancing, and the transfer of renewable generation between regions experiencing different weather and demand conditions.
High voltage direct current technology is widely used for long distance subsea transmission because it allows operators to control the direction and volume of power transferred across the link. Over extended cable routes, it also avoids several of the reactive power and charging current constraints associated with alternating current subsea systems.
A completed interconnector would require converter stations at both ends, subsea and onshore cable systems, protection and control equipment, grid interfaces, telecommunications, and coordinated testing across the British and German transmission systems. Each element must operate within the technical rules of its host network while remaining compatible with the wider link.
The acquisition extends an existing investment relationship between CPP Investments and Elia Group, while moving WindGrid further into international transmission development beyond Elia’s regulated activities in Belgium and Germany. Elia Group operates those national networks through Elia Transmission Belgium and 50Hertz.
Cross border capacity enters a heavier delivery phase
European interconnection now carries a broader system role than electricity trading alone, particularly as offshore wind capacity grows around the North Sea. Additional links can move renewable power between markets, relieve some periods of oversupply, and reduce dependence on domestic generation when local output falls.
Britain and Germany both experience periods when renewable production and electricity demand diverge, although a controllable link can only move power where sufficient transmission capacity exists behind each landing point. Internal constraints can still limit the amount imported or exported even when the interconnector itself remains available.
Converter stations must therefore connect into sufficiently strong networks, while both systems need the ability to transport electricity away from the point of connection. Transmission reinforcement, connection sequencing, outage planning, reactive power provision, and system operability studies will remain central to the project’s development.
Regulatory treatment will influence Tarchon’s revenue certainty, financing structure, and allocation of development risk. Ofgem’s modified access arrangements for Viking Link illustrate how capacity allocation and commercial rules continue to evolve after interconnectors enter service.
Large transmission projects require substantial expenditure before construction begins, including seabed surveys, route engineering, environmental assessment, land rights, converter station design, procurement planning, and engagement with regulators and system operators. Delays within one workstream can affect equipment reservations and the sequencing of later construction.
Demand for converter technology, high voltage subsea cable, transformers, reactors, switchgear, cable laying vessels, and specialist engineering services has increased as European transmission operators advance interconnectors, offshore wind links, and coordinated offshore grids at the same time.
Manufacturing capacity for some of the most specialised components is concentrated among a limited number of suppliers, while cable installation depends on a small fleet of suitable vessels and experienced crews. Procurement therefore needs to begin early enough to secure factory slots without committing the project before its regulatory and commercial framework is sufficiently mature.
The ownership structure gives Tarchon access to institutional capital with a long investment horizon, alongside Elia’s experience in transmission operation and major infrastructure development. That combination supports the next phase, although it does not remove consent, procurement, construction, or connection risk.
Operational performance will eventually depend on more than the 1.4GW rating. Converter availability, cable reliability, maintenance arrangements, network constraints, market coupling, and outage coordination will determine how much electricity the link transfers over its service life.
The acquisition is expected to complete by the end of 2026, subject to regulatory approvals and customary closing conditions. Tarchon must then progress from a development asset into a fully specified transmission scheme, with its value shaped by the strength of the wider grids on both sides of the North Sea.
