The government's promise to amend its renewables obligation legislation (RO) to award offshore wind generation 1.5 Renewables Obligation Certificates (ROCs) for each MWh produced, compared with 1 ROC/MWh for onshore wind, lies behind the market rejuvenation. The RO requires electricity retailers to buy sufficient ROCs to meet an annually rising green power mandate, providing wind generators with significant extra revenue in addition to that from sales of the physical electricity.
With two projects completed last year, albeit one of them just a 10 MW demonstration project of two turbines, 2007 bucked the trend of the previous four years which each saw just one UK offshore wind farm commissioned. The 90 MW Burbo Bank station in Liverpool Bay and the deepwater Beatrice project off the north-east coast of Scotland bring UK offshore capacity to 404 MW from six wind stations. The 2007 projects also break Vestas' dominance of turbine supply to the UK offshore market. Burbo Bank is the first outing in British waters for Siemens machines, now the supplier of choice for most of the upcoming offshore projects. And Beatrice is the first offshore deployment of German Repower's 5 MW turbines. They are the largest so far to be installed at sea.
The outlook is for more rapid development of the British offshore resource. This year should see the completion of Centrica's Lynn and Inner Dowsing projects off the east coast with a combined capacity of 194 MW. Each project is using 27 Siemens turbines. Three further projects with a combined capacity of 378 MW are under construction and due for commissioning in 2009 (table).
The momentum does not stop there. Site work is set to start this year on the first project from the second round of site leasing for UK offshore development. From September, Warwick Energy has reserved A2SEA's construction vessel Sea Jack for installation of turbine foundations at its 300 MW Thanet project in the outer estuary of the River Thames. Following Vestas' announcement last month that it is returning its 3 MW turbine to the offshore market after working through bearing failure problems in the Hansen gearbox, it is all systems go for Thanet. "We hope to sign the contract in the near future," says Warwick Energy's Mark Pettersen. He expects the wind farm to be operational by the end of 2009.
In Ireland, the offshore market at last looks set to take off after the government's announcement last month of guaranteed power purchase prices for offshore wind of EUR 140/MWh for the first 15 years of operation. Prospective developers immediately announced plans for 2000 MW of offshore wind farm construction in Irish waters in the next five years (page 32). Ireland has one offshore demonstration wind farm so far, the 25 MW Arklow Bank project of GE turbines commissioned in 2004.