Bringing it together – Multi-purpose interconnectors

While onshore continues to dominate mainland European wind development, offshore wind is now a central part of many countries' energy strategies, perhaps most strikingly in the case of the UK.

Expectations of a dramatic increase in European offshore power over the next decade – both via conventional turbines and a new generation of floating rigs – has brought into focus the increasingly central issue of how to create the necessary infrastructure to efficiently transport power from the North Sea to the onshore grid.

Currently, offshore wind farms are connected to shore individually and are typically only connected to the grid of one jurisdiction. However, as offshore wind capacity increases, a new generation of subsea cables will be required to meet the demands of decarbonising the grid, dubbed multi-purpose interconnectors (MPIs) or offshore hybrid assets (OHAs), depending on where the connecting wind farms are located.

MPIs allow windfarms to be connected to another country's grid, or even each other, making them far more versatile tools in unlocking the huge potential of offshore wind. MPIs and OHAs would also enable a group of offshore wind farms to create hubs whereby green electricity is efficiently transmitted to shore, instead of each farm being connected to land separately.

The benefits are extensive. These next generation cables would allow for the efficient transmission of power to where it is needed most, reduce the number of connections required and associated infrastructure, and increase energy security with reduced costs for consumers. Such infrastructure is also seen as key to bolstering the North Sea as an offshore wind hub.

Early MPIs include Krieger's Flak, connecting offshore wind projects in Denmark and Germany. In the UK, power regulator Ofgem is currently considering applications by the projects Nautilus (connecting the UK and Belgium) and LionLink (connecting the UK and the Netherlands) as part of its application process for regulatory support for interconnectors and MPIs.