New capacity more than doubled in 2015 due backlog; existing projects to bring more expansion in coming years.
Growth in new offshore wind capacity in Europe is to slow this year after more than doubling in 2015, an industry report said on Tuesday.
"New capacity additions will be lower in 2016 than 2015 though should then rebound, and we can expect to have (an installed total) over 20 GW (20,000 MW) offshore wind by 2020," said the chief executive officer of the European Wind Energy Association (EWEA), Giles Dickson.
The report for 2015 showed that new capacity linked to onshore grids totalled 3,019 megawatts (MW) last year after 1,483 MW in 2014.
This was mostly due to a strong backlog of network connections in Germany in that particular year, EWEA said.
Total installed offshore capacity now stands at 11,027 MW, enough to allow coverage of 1.5 percent of the European Union's total electricity consumption, it said.
Among the largest new wind farms were the 576 MW site at Gwynt y Mor in the UK and 600 MW Gemini in the Netherlands, while most of Germany's new sites amounted to 288 MW.
Work is ongoing at six existing projects in Germany, Britain and the Netherlands, the most active three out of a total 11 countries involved, which will contribute an additional 1,900 MW, bringing the cumulative total to 12,900 MW in the medium term.
In monetary terms, ten new projects worth 13.3 billion euros ($14.51 billion) reached final investment decision stage in 2015, a doubling over 2014 values.
Among turbine suppliers, Germany's Siemens in 2015 remained market leader in terms of annual installations, contributing a total 1,816 MW total, followed by Adwen, Senvion and Vestas.
Utilities and institutional investors say they are keen on offshore wind, which is beginning to get more established and proven even though governments have curbed early-day subsidies that were aimed at helping the young technology reach maturity.
German top utilities E.ON and RWE have taken the place of lesser known rivals as key developers, jointly accounting for 17.1 percent of all new connections in 2015, according to EWEA.
The EWEA has loosely identified 26,400 MW of wind farms in Europe that might be constructed offshore over the next decade, and a total 63,500 MW at planning stage.
Reporting by Vera Eckert