Europe moves slowly but surely towards offshore supergrid, By Darius Snieckus, Recharge News,Updated: Friday, July 24 2015

A North Sea supergrid is seen as the spearhead of a pan-European network that would underpin greater co-operation to integrate renewables

Tennet

Europe is leading the world in developing its vast offshore wind resource, but building the transmission network to bring power to shore is proving a slow-rolling process, with EU's 28 leaders only signing up earlier this year to a package of policies that include taking "urgent measures" to reach a minimum interconnection target of 10% of total generation capacity by the end of the decade and 15% by 2030.​

Construction of a North Sea supergrid — seen as the spearhead of a pan-European network that would underpin a flexible energy market and greater regional co-operation to integrate renewables — could at last be gathering pace, now that the main contracts for the biggest of several planned "ring main" offshore interconnectors have been handed out.

Last week, contracts totalling €1.5bn ($1.65bn) were awarded for the 1.4GW North Sea Network (NSN) trunkline between Norway and the UK. Cable suppliers Prysmian and Nexans will provide the high-voltage DC (HVDC) link, with the $450m order for the converter stations at either end of the line going to power technology group ABB.

Prysmian will handle the 950km of line for the North Sea sections of the route, with cables fabricated at its Arco Felice factory in Naples, Italy, and installation carried out by the cable-laying vessel Giulio Verne. Nexans is supplying the fjord, tunnel and lake sections of the NSN, made up of 500km of HVDC cables manufactured at its Halden, Norway, plant, which will be laid by its Skagerrak vessel. ABB will deliver converter stations using its HVDC Light technology.

NSN, slated to be in operation by 2021, will form a key link in a newbuild offshore transmission infrastructure that will include the recently approved 1.4GW NordLink line between Norway and Germany; as well as the Viking Line between Denmark and the UK; and the Nemo Link between Britain and Belgium, both of which are at an advanced planning stage.

Tied together with existing interconnectors such as the 1GW BritNed line linking the UK and the Netherlands, the Norway-Netherlands' 700MW NorNed and the 2GW IFA line connecting the UK and France, and the potential for a supergrid capable of pulling in the North Sea's rich wind resources — potentially 65GW by 2030, enough to make up more 25% of electricity generation in Europe — comes into focus.

Although critical to the longer-term future of Europe's renewables vision, bigger and beefier interconnectors are only a first step in the region's electricity infrastructure build-out. What is needed, according to the offshore wind industry, is a"meshed" grid woven between these trunklines that would mean the giant projects off Britain and Germany now on the drawing boards could be wired in over much shorter (read "less expensive") distances.

The savings from a meshed grid would be enormous. Estimates varying widely, from €1.5bn to €13bn, but even by the European Commission's more conservative calculations, the figure could be €5.1bn — a major fillip for the fast-evolving offshore wind business.

Expansion and reconfiguration of the European grid to deal with coal and nuclear plant retirements and the rapid growth of offshore wind generation represents a big prize indeed, according to figures from Navigant Research. Over the next decade, the continent is expected to account for more than half of the submarine cable projects around the globe, a market forecast to grow from $16.8bn this year to $24.8bn in 2024.

Led by Europe's Energy Union framework project, the Dutch, who take over the EU presidency in the first half of next year, could exercise great sway in how swiftly plans for a North Sea network move from idea to reality.

But it could be Britain, armed with a soon-to-be-unveiled study — contributed to by developers of the Dogger Bank, Hornsea and East Anglia mega-zones — on the regulatory changes needed for a meshed grid that proves most influential over the medium term, not least as it holds the EU reins for the second half of 2017.

The paradox for offshore wind infrastructure is that unlike the wider sector, it is the regulatory side that is lagging behind the technology.

Ultra-large turbines and high-capacity, low-loss HVDC lines are moving towards the mainstream. Matters of financial and regulatory logistics and how cross-border offshore power is transported, allocated and traded need concrete resolution before the European supergrid can be reeled out in full.