We've seen stream of brand new innovations in the field of wind power recently, from typhoon turbines that harness the power of storms, to the Vietnamese villagers building DIY wind turbines from plastic waste. The latest new wind power project, headed up by TenneT, the operator of the Netherlands’ electric grid, is seeking to build a new and audacious wind farm more than 100km out to sea, around eight times the size of Manhattan. The project will seek to build power generation capacity of up to 30 GW of power, an enormous amount - at least double all of the existing offshore power installed across Europe today.
It's a renewable energy monster project, but it could be up and running as soon as 2027 if things go right.
TenneT's is currently studying the feasibility of using Dutch knowledge in reclaiming land from the sea in an area known as Dogger Bank, to build an artificial island in a shallow area of the North Sea, as oppose to floating platforms which have been used in the past.
Complete with port and maintenance facilties, the island would be significantly more useful than a as well as simplifying the construction and maintenance of the wind farm. In addition, it may be possible to build a 'WindConnector' link to the UK, acting as an interconnector for different North Sea country grids.
But why hasn't this been looked at before, and what makes it such a good idea now?
Let's step back and take a look at how the wind blows.
Offshore winds are far more reliable than those on land - studies show that they are 40 per cent more consistent out at sea, and the further out in the ocean the better. It's far easier and cheaper to build turbines on land, but the maximum efficiencies are much lower, so it's a trade off, and onshore farms can attract opposition from locals.
In the European Union, both on and offshore wind farms account for almost double the power generation of solar power farms, and it is the fastest growing area of power generation. Offshore wind power via nearshore opportunities has boomed in Northern Europe, where all of the major and largest offshore wind farms exist - mostly near the United Kingdom and Germany. (The 630 MW London Array in the United Kingdom is the largest offshore wind farm in the world, 20km offshore.)
The growing problem for offshore wind farms is that nearshore opportunities are filling up. The easiest locations with the best winds have already been built on, leading to a necessity to build further out to sea. The advantages are stronger winds, but there are many disadvantages in terms of installation and maintenance costs.
And there are physical energy limitations as well. Wind farms generate their power as alternating current (AC), which is what we use at home from mains power, and is what boils our kettles and cooks our toast. It's actually one of the advantages of wind, as complex current conversion aren't required, only transformers to convert the wind power to higher-voltages for transmission, which is how traditional power stations work as well.
The problem for far offshore wind farms is the transmission technology over undersea cables. AC transmission over long distances - such as the 100km back to the Netherlands (or to other countries, such as Norway, Germany, and the UK) from TenneT's proposed wind farm, is more problematic and costly than utilising an undersea cable that runs on direct current (DC). To convert wind farm output from AC to DC, though, requires significant equipment, made all the more difficult given the fierce nature of the ocean and exposure to the elements either above or below the water.
Hence the idea: an island to house AC-DC current conversion technology, along with possible interconnectors. Will it work?
Third-party experts are interested and believe the idea is credible, but aren't sure. Peter Atherton, an energy analyst at Cornwall Insight, told The Guardian that it was an expensive plan
“It’s going to be expensive compared to what they produce locally [from windfarms nearer the coast],” he said. “It sounds a very interesting idea ... as the industry matures, you’d very much expect them to start thinking outside the box. Whether the economics pan out, whether you really can sell North Sea wind out to the continent, is questionable.”