The project was conceived in February 2008, as part of the Danish government's Energy Policy Agreement.[3] The wind farm cost an estimated 10 billion Danish kroner (€1.35 bn, US$1.65 bn). During operation, DONG receives a feed-in tariff of 1.051 DKK/kW·h (17 US¢/kW·h) for the first 20 TW·h (about 12–13 years of production),[4] whereas the 207 MW Rødsand 2 receives 0.629 DKK/kW·h for 10 TW·h.[5]
DONG Energy was the only bidder for the project, and received the license to build it in 2010.[6][7] Newsmedia and politicians suggest a tight schedule with tough sanctions as reasons for the single bid and higher price,[8][9] and the subsequent Horns Rev 3 offshore wind farm had 4 bidders in 2015 and costs 0.77 DKK/kW·h, well below the 105 øre at Anholt.[10]
A platform holds 3 transformers which increase voltage from 33 to 220 kV for transporting the alternating current power 25 kilometres (16 mi) to land through a single 3-conductor cable (diameter 26 cm or 10 in)[13] and a further 56 km (35 mi)[14] to Trige (near Aarhus) where a 400 kV main power hub can distribute the power.[15][16] There are switchyard reactors along the cable to provide reactive power to compensate for line capacitance.[17]
The agreement required first power to be produced before the end of 2012, and be fully commissioned before the end of 2013.[12]
In March 2011, DONG Energy sold 50% of the Anholt wind farm to a consortium consisting of PensionDanmark (30%) and PKA (Pensionskassernes Administration, 20%) for DKK 6 billion (US$1.14 billion) payable in 4 rates between 2011 and 2013.[18][19]
Usually, turbines are placed in a grid pattern of lines and rows. But the turbines of AOWF are placed in an unusual pattern, governed by two principles: put most of them along the edges, and put most in undisturbed airflow from the main direction, which is West-southwest. This would increase production by 1.5%, a lifetime value of more than 100m DKK.[20]
Construction
On 31 December 2011, the heavy lift vessel (HLV) Svanen placed the first foundation monopile.[21]
Official construction of the wind farm started on 13 January 2012.[22]
The first turbine was installed on 3 September and connected to the Danish power grid on 21 September.[23]
In May 2013, AOWF became Denmark's largest wind farm when 59 turbines were grid connected, totalling 212MW and surpassing Horns Rev 2. The vessel Sea Installer erected a complete tower, and installed a wind turbine in 7 hours.[24]
On 19 May 2013, the installation vessel Sea Power erected the last of the 111 turbines at Anholt Offshore Wind Farm.[25]
The wind farm achieved full power in June 2013,[26][27] and was inaugurated and commissioned on 4 September 2013.[8][28]
Operation
The connection cable has been out of service twice; first the land cable failed for a week in 2014 costing Energinet.dk 9 million DKK in compensation to DONG. In February 2015 the sea cable failed, and Anholt island reverted to its diesel engines.[29]
