WindEurope has published a summary report for 2018 about offshore wind sector in Europe.
It is available on the WindEurope website.

Key information:

• 2.6 GW was installed in Europe in 2018 – it is 18% increase in power,
• 651 MW was installed in the North Sea, 395 MW in the Irish Sea, 387 MW in the Baltic Sea and 229 MW in the Atlantic Ocean,
• 15 new offshore wind farm projects were launched,
• there are 4543 turbines in Europe operating on 105 offshore wind farms in 11 countries,
• the United Kingdom and Germany remain the leaders,
• the average power of installed turbines is 6.8 MW, and the largest turbin with a capacity of 8.8 MW was installed in the British project.
  

The report also refers to the Polish plan for the development of offshore wind farms – 10 GW until 2040.