ENGIE Solutions and Iemants score Hollandse Kust (west) alpha offshore station contract

© TenneT

TenneT has awarded a joint venture between ENGIE Solutions and Iemants the contract for the offshore transformer station Hollandse Kust (west) Alpha (HKWA). The transformer station is scheduled to be commissioned in 2024.

Earlier this year, the consortium won the contract for the construction and installation of the offshore transformer station Hollandse Kust (north). Both contracts follow a European tender launched by TenneT earlier this year.

The HKWA contract includes the engineering, purchasing, construction, offshore installation, connection and testing of the offshore transformer station. The topside and the jacket are built separately on land and installed on site at sea using a crane vessel.

Standard design
The HKWA station is part of the standardisation of 700MW platforms introduced by TenneT. This should ensure a substantial reduction in development, construction and maintenance costs. Following the design, the jacket is 49 meters high and consists of 1,930 tonnes of steel. This steel construction is firmly anchored in the seabed with piles at 28 meters water depth. The topside has three (inner) floors and an outer deck. It weighs approximately 4,300 tonnes and is 47 meters long, 35 meters wide and 25 meters high (excluding antenna tower and top deck crane).

The offshore platforms Hollandse Kust (north) and (west Alpha) will be the fifth and sixth large-scale grid connections for offshore wind energy in the Netherlands to be built and operated by TenneT. The first high-voltage connections for the wind farms at Borssele will already be operational in 2020, and the connections for the Hollandse Kust (south) will follow in 2022. TenneT will realise approximately 9.6 GW of high-voltage connections in the Dutch North Sea by 2030.