Artificial island for wind power envisioned in North Sea

A European electricity network operator has envisioned building an island in the middle of the North Sea, which will collect, distribute and transmit power generated from numerous wind turbines nearby.

TenneT, which delivers electricity to about 41 million people mostly in the Netherlands and Germany, presented a vision for building a large European electricity system in the North Sea, according to its official web site.

Central to the vision is an artificial island to which wind farms can be connected and from where the generated wind electricity will be distributed and transmitted over direct current cables to the North Sea countries such as the Netherlands, the United Kingdom, Belgium, Norway, Germany and Denmark, according the web site.

An artificial island to serve as a hub for wind farms aims to slash costs.

As near-shore spots for turbines grow increasingly filled up, more wind farms are pushed ever further off the coast. One disadvantage is that the costs will be significantly higher. The construction and maintenance of the wind farms are higher and these must be connected via many relatively expensive, single direct current connections.

Alternating current technology cannot be used for connecting offshore wind farms far out at sea because of an unacceptably high loss of electricity during transmission to the onshore grid.

However, by building an island surrounded by wind farms (at a relatively short distance), wind energy obtained way out at sea will be just like in near-shore wind. The smaller distance – between the wind farm and the island – will allow use of the far cheaper alternating current connections.

One possible location for the island is Dogger Bank, 125 kilometers off the UK’s East Yorkshire coast, which is relatively shallow but with strong wind and big space, TenneT said.

The company said its thinking is based on an island with a modular structure, with each module covering approximately 6 square kilometers, enough to provide space for connecting roughly 30 GW of offshore wind capacity.

The number is very ambitious: at the beginning of 2017, Europe’s total installed capacity of offshore wind farms is 12.6 GW, according to industry group WindEurope.

The vision, dubbed the North Sea Infrastructure, will be in TenneT’s talks with the EU and its member states. Ideally, the island could perhaps be built between 2030 and 2050, it said.