HelWin1

Offshore GridOperationalDE576 MW250 kV130 km

Basic Information

Also known as:HelWin1 HVDC link, HVDC HelWin1

Status:Operational

Capacity:576 MW

Transmission Model:TSO Build & Own

Owners:

TenneT TSO GmbH(100%)

Project Company:

TenneT TSO GmbH

Type:offshore grid

Expected Life:30 years

Website:www.prysmian.com

Description:

HelWin1 is a TenneT-owned High-Voltage Direct Current (HVDC) offshore grid connection that evacuates power from the Nordsee Ost and Meerwind Süd/Ost offshore wind farms to the German mainland. The link uses voltage-source converter (VSC) HVDC technology (Siemens HVDC Plus) at an offshore converter platform (HelWin alpha) and an onshore converter...

Supply Chain (0)

Project Timeline (0)

No lifecycle events recorded yet.

	North Sea	Schleswig-Holstein
Landfall	N/A	Büsum, Schleswig-Holstein, Germany
Grid Connection	—	Büttel 380 kV substation

Financial

€500M€646.6M adj.€8.64k/MW-km

www.prysmian.com (Jul 2010)

CAPEX:€500M

Adjusted to 2025¹:€646.6M

Cost Intensity¹:€8.64k per MW-km

Estimate Date:Jul 2010

Source:www.prysmian.com

Notes:

Approximate contract award value (~€500M) for the Siemens–Prysmian consortium to deliver the HelWin1 turnkey grid connection; Prysmian's portion of the contract was reported as >€150M. This is the contract award...

¹ Cost inflated in local currency then converted to euros (where applicable).

Cable Specifications

HelWin1 HVDC export cable (HelWin alpha – Büttel)

Büsum, Schleswig-Holstein, Germany

2 × 250 kV HVDC · symmetric monopole · copper 962 mm² 110 mm dia. · XLPE (Cross-linked Polyethylene) · 576 MVA · 130 km · 30 kg/m

System:2 × 250 kV HVDC · symmetric monopole

Construction:copper · 962 mm² · 110 mm dia.

Insulation:XLPE (Cross-linked Polyethylene)

Power rating:576 MVA

Route length:130 km(85 subsea · 45 land)

Weight:30 kg/m air

Burial depth:

Project sources report that the HelWin1 export cable was post‑laid and subsequently buried where feasible, with routine target burial depths in the order of ~1–2 metres. Offshore segments were embedded...

Fibre optic:

Sources indicate the HelWin1 link uses fiber‑optic provisions for system control, protection and monitoring: fiber‑optic communications are used for real‑time synchronization and remote control of the offshore and onshore VSC...

HelWin alpha – Nordsee Ost HVAC submarine cables

155 kV HVAC

System:155 kV HVAC

Route length:0 km land

Burial depth:

Sources describing the HelWin1 project state that subsea cables were post-laid and then buried using seabed ploughing to provide protection against external damage. Published accounts indicate a typical target/nominal burial...

Fibre optic:

Project and contractor documentation and technical summaries indicate fibre‑optic capability is integrated into the HelWin/associated cable systems for control, protection, telemetry and operational communications between the offshore platform(s) and onshore...

HelWin alpha – Meerwind Süd/Ost HVAC submarine cables

155 kV HVAC · 288 MVA

System:155 kV HVAC

Power rating:288 MVA

Burial depth:

For the HelWin1 subsea cable system Prysmian/Prysmian‑Siemens works reported post‑lay burial using seabed ploughing to embed the submarine cables to a nominal depth of roughly 1–2 m below seabed. Sources...

Fibre optic:

Project documentation and technical summaries indicate fibre‑optic elements are integrated into the HelWin cable systems and associated cable bundles for control, protection and monitoring purposes. Public sources describe fibre‑optic controls...