Setting up wind farms out at sea is a formidable

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1 Wind Energy offshore in Europe Creating facts at sea Rødsand I formerly Nysted wind farm off the Danish coast totals 72 Siemens wind turbines, with a capacity of 2.3 MW each. Foto: Ole Christiansen/E.ON Offshore wind power continues to advance: shipyard and port developments are making progress and soon there will be enough construction vessels available. However, almost everything depends on the policy framework conditions in the UK and Germany. Setting up wind farms out at sea is a formidable technical challenge. For more than ten years, the European industry has been dream ing of the great boom. It had to be verypatient how ever, because the realisation of offshore projects has turned out to be far more costly and difficult than expected. It was the Danes who did the pioneering work and set up the Vindeby wind farm (5 MW) in the Baltic Sea in The next two went up in 1995 and 2001, but were followed by two setbacks: the Horns Rev (2002) and Nysted (today s name: Rødsand, 2003) wind farms both came to a halt for months because of technical defects. All overly optimistic predictions, which had projected an offshore boom for 2005 or 2006, were destined for the trash bin. By the end of 2009, a mere 2,056 MW had been installed in European waters, an amount which had originally been expected a couple of years earlier. Today, experts have become wiser and do their sums more carefully. Costs in particular have had to be revised upwards. The amount of money to be invested into port and shipyard development was initially just as underrated as the number of construction ships required. The offshore market is lagging 16 years behind The time frame recently established by EWEA, the European Wind Energy Association, looks rather more 172

2 Offshore projects in the UK, Ireland, France, Belgium and the Netherlands Argyll Array 1,500 MW Islay 680 MW Kintyre 378 MW Inch Cape 905 MW Bell Rock 700 MW Neart na Gaoithe 360 MW Forth Array 415 MW Beatrice 920 MW Beatrice 10 MW Moray Firth 500 MW Solway Firth 300 MW Robin Rigg A+B 180 MW Firth of Forth 500 MW Blyth 4 MW Dogger Bank 9,000 MW Offshore wind farms around Great Britain Wind farms in operation under construction approved planned Round 3 Scottish Round Status: July km Wigtown Bay 280 MW Irish Sea 5,000 MW Arklow Bank 25 MW Walney 450 MW West Duddon 500 MW Teesside 90 MW Cirrus Array 270 MW Ormonde 150 MW Hornsea 3,000 MW Westernmost Rough 240 MW Barrow 90 MW Gwynt y Mor 750 MW Humber Gateway 300 MW Inner Dowsing 97 MW Triton Knoll 1,200 MW Race Bank 500 MW Sheringham Shoal 315 MW Dudgeon East 300 MW Burbo Bank 90 MW North Hoyle 60 MW Rhyl Flats 90 MW Lynn 97 MW Lincs 270 MW Docking Shoal 500 MW Scroby Sands 60 MW Norfolk 5,000 MW Egmond aan Zee 108 MW Prinses Amalia 120 MW Scarweather Sands 108 MW Gunfleet Sands I+II 172 MW London Array 1,000 MW GreaterGabbard I+II 500 MW Thornton Bank 30 MW Bristol Channel 1,500 MW Kentish Flats 90 MW Thanet 300 MW Hastings 500 MW Planned and implemented offshore wind power projects Graphic: Eilers-Media West Isle of Wight 500 MW Côte d'albâtre 105 MW 173

3 A Wind Energy offshore in Europe Offshore projects in Germany, Denmark and Sweden Samsø 23 MW Tunø Knob 5 MW Horns Rev MW GERMAN BIGHT Sandbank MW Nördlicher Grund Dan Tysk Horns Rev 160 MW Butendiek 288 MW Esbjerg Sprogø 21 Vindeb Hochseewindpark Nordsee Bard Offshore 1 Veja Mate Deutsche Bucht 273 MW Borkum Riffgrund West Borkum Riffgrund I + II Global Tech I Hochseewindpark He dreiht Nordsee Ost 295 MW Borkum West II MEG Offshore 1 Alpha Ventus 60 MW Amrumbank West Meerwind Rødsand MW Gode Wind Gode Wind II Innogy Nordsee I 990 MW OWP Delta Nordsee I Riffgat 108 MW Nordergründe 90 MW realistic than all previous forecasts. According to their estimations, the offshore market is still at an early stage of its development, roughly 16 years behind the onshore market. Some figures illustrate this: six wind farms totalling a capacity of 577 MW were installed during the previous year, thus equalling the level of the 1993 onshore market. EWEA expects the offshore market to develop steadily, like the onshore market. More than 1,000 MW are to be installed this year and more than 2,000 MW in For 2016, EWEA predicts a capacity just short of 4,000 MW, on a par with the onshore market in The assumption of an offshore market growing strongly and permanently within the next 10 years is based on an optimism fed above all by the political objectives in just two countries: the governments in Germany and Great Britain are firmly intent on making wind power a strong pillar of their power supply. Due to geographical conditions, this will only be possible in either country by a massive expansion of offshore wind power. The German government has set itself the ambitious goal of installing a total capacity of 25 GW in the North and the Baltic Sea by the year The British government goes even further: over and above the 9 GW projected for the first two rounds of tenders (of which 1 GW has been set up to date), there will be another 32 GW from Round 3. The zones have recently been assigned to financially strong investors, most of them major utility companies (see map on page 173). It will not be until the year 2030 before we come anywhere near this highly ambitious target. 174

4 nholt Utgrunden 10 MW Yttre Stengrund 10 MW Planned and implemented offshore projects in Germany, Denmark and Sweden. Due to its promis ing wind conditions, the German Bight is almost fully booked. Graphic: Eilers-Media Copenhagen Middelgrunden 40 MW MW y 5 MW Rødsand 166 MW Lillgrund 110 MW Kriegers Flak MW Baltic MW Baltic 1 48 MW BALTIC SEA Ventotec Ost 2 Arconabecken Südost Offshore wind farms in the German Bight and in the Baltic Sea Wind farms in operation under construction approved planned Power lines approved planned km Status: July 2010 In other European countries, objectives have been set significantly lower, e.g. in Denmark which saw offshore wind power getting off the ground 20 years ago. While state support in France is quite substantial, a boom is not yet on the horizon. To date, only the Côte d Albâtre wind farm has been permitted (see page ). In the Baltic Sea, but also off the Dutch, Belgian and French coasts, some wind farms will certainly go up in the next few years. The market, however, will essentially depend on the political framework conditions in Germany and the UK. In either country, investors can rely on relatively high state-guaranteed revenues from electricity sales and on benevolent political support. The limit 6 offshore wind farms (installed in 2009) 40 Water depth [m] 30 Alpha Ventus 20 Sprogø Horns Rev 2 10 Rhyl Flats Gunfleet Sands Robin Rigg Distance to shore [km] Distance from shore and water depth First generation wind farms are located inside the 20/20 limit (maximum distance from shore 20 km, maximum water depth 20 m). Horns Rev 2 and Alpha Ventus are second generation wind farms. Graphic: Eilers-Media 175

5 Wind Energy offshore in Europe An industry of its own in the making Entering offshore wind power is a far-reaching decision, as it does not make very much sense to just go half-way. It requires the lengthy and costly development of an industry of its own, which will only pay off if business remains stable for decades to come. Creating facts is now essential to provide this stability. Starting off was relatively straightforward. No high investments were required, as the first offshore wind farms were set up near-shore in shallow waters. Concrete foundations or monopiles were sufficient as foundations. Wind turbines were installed which had originally been designed for onshore operation and thereafter been adapted to conditions at sea. As no special construction vessels were available, existing work boats were chartered or ships were converted to meet these requirements. In hindsight some things make a makeshift impression. Everything went well, however, as the first generation offshore wind farms were not very demanding. All this is now changing. When the Alpha Ventus wind farm was installed in the German Bight last year it turned out that the North Sea was not to be trifled with. Because of high swells and gusting winds, assembly teams were obliged time and again to take unscheduled breaks. That made installation a drawnout process. Seven months were needed for anchoring the twelve foundations and the subsequent erection of the wind turbines. This was especially due to the fact that construction vessels deployable in rough seas were not available. Alpha Ventus is the first wind farm installed in deep water and simultan eously at a great distance from shore (see diagram on page 175), thus serving as a test field for second generation wind farms. These are located beyond the 20/20 limit (at a maximum distance of 20 km from shore and a maximum water depth of 20 m), posing quite different challenges in terms of installation and operation. Shipyards and factories to be upgraded One of the first offshore turbines currently being installed for Bard Offshore 1 in the German North Sea. Photo: Ingo Wagner/dpa Even now it is clear that a lot must happen in the running-up stage. Shipyards which can manufacture large steel foundations and transformer substations are needed to begin with. Secondly, factories are required at the coast for mass-producing rotor blades, nacelles and tower sections which can be loaded directly from the quayside onto the ship. This requires a quayside of 150 to 250 m in length and a load carrying capacity of 3 to 6 tons/m 2, which implies that quite a few ports will have to be developed. In addition, large storage spaces will be required to serve as buffers if production gets ahead of installation. These spaces still need to be created in most coastal locations. Furthermore, purpose-built construction vessels will be needed that are able to carry and set up several (complete or unassembled) wind turbines and not just when the sea is calm, but also in meter-high waves. There are plenty of shipyards in Europe, but a lot of them have seen a decade-long decline and are no longer capable of constructing large foundation structures and transformer stations. From the twelve foundations for the Alpha Ventus wind farm, none were actually constructed in Germany. The six tripods were manufactured in Norway and the six jackets in Scotland. It is therefore high time to re-instil life into German shipyards. Tower 176

6 manufacturer SIAG recently bought Nordseewerke at Emden, in order to produce monopiles, jackets, tower sections and machine housings there. Upgrading individual ports to become offshore bases is making headway. The three German port cities of Bremerhaven, Cuxhaven and Emden are equipping themselves for the offshore boom. Esbjerg (Denmark ), Flushing (Netherlands) and Dunkirk (France) could benefit from the upturn, too. The majority of ports that are basically fit to become offshore locations are located in the UK. EWEA has recently shortlisted 20 potential offshore locations, amongst which figure Great Yarmouth, Humber, Tyneside, Dundee and Barrow-in-Furness. Several new purpose-built ships will be available at short notice. Wind Lift I was ready to go to sea in March, and is currently setting up wind farm Bard Offshore 1. RWE Innogy has ordered two ships from Korean hipyard Daewoo. From 2012, they are intended to construct wind farms Nordsee Ost, Innogy Nordsee I and Gwynt y Môr. Moreover, Beluga shipping company and Hochtief construction company have founded a joint venture to build several purposebuilt ships that can be deployed in up to 2 meter high waves. A European project on the horizon International cooperation was indispensible when setting up the Alpha Ventus wind farm. It is therefore evident that the large offshore projects of the future may just be asking too much of the capabilities of any one country. Pushing forward offshore wind power ought to be seen as a European project. This seems perfectly natural, because the whole of Europe or at least its northern half will benefit from power generation at sea, as enormous volumes of electricity are planned to be exchanged between individual adjacent countries. To help this run smoothly, however, grid codes and tariffs will have to be harmonised. This can be illustrated using the example of Baltic 2 and Kriegers Flak 2 wind farms, which are to be built in the Baltic Sea north of Rügen (see map on page 175). They are located in the border triangle in mid-sea between Germany, Denmark and Sweden. A wind farm on the Swedish side would be ideally placed to supplement this power plant. In this way each of the three wind farms could be connected to one national grid, and linking the wind farms to each other would create a hub for a supergrid. Power could be easily exchanged between the countries depending on the demand at any given moment. However, as long as rates differ, electricity will flow only in the direction of the highest tariff in this case Germany. Demand-side management will not be feasible in that case. Much therefore remains to be done at the political level, to establish a level playing field for offshore wind power. Detlef Koenemann In offshore wind installation, hardware is part of the solution. Know-how is the key.