The industry body said that last year was a record one for the offshore wind industry, with 1.6GW of new capacity installed. This represents a 34% increase on the capacity installed in 2012.
However, EWEA said that two thirds of that capacity came online in the first half of the year. It also points to the fact that there are currently 11 projects under construction compared with 14 at this time last year.
"The unclear political support for offshore wind energy — especially in key offshore wind markets like the UK and Germany — has led to delays to planned projects and fewer new projects being launched," said Justin Wilkes, EWEA deputy CEO.
This means that installations are likely to plateau until 2015, followed by a decline from 2016, he claimed.
However, EWEA highlighted that 3GW are currently under construction in European waters and 22GW have been consented.
In its annual report on the European offshore industry, EWEA said that Siemens supplied 69% of all offshore turbines in 2013, while Dong was the pre-eminent developer, responsible for 48% of the connected turbines.
A cumulative 2,080 turbines are now installed and grid-connected, making a total of 6.6GW across 69 wind farms in 11 European countries.
The average offshore wind farm size was 485MW in 2013, 78% bigger than the previous year.
"The trend towards larger projects is expected to continue over the coming years," said EWEA.