German offshore wind operators raised generation capacity at sea to just under 4.4 gigawatts (GW) in the 12 months ended in June, an increase of 47 percent over the same date in 2016, electricity network company TenneT said
TenneT plays a key role in the sector because it is responsible for linking North Sea wind farms to onshore grids in the states of Lower Saxony and Schleswig Holstein.
It said the comparable 2016 number was 3 GW. TenneT said it had prepared offshore to onshore connection capacity of 5.2 GW to account for the anticipated rise in installations.
The government's national offshore capacity target is 6.5 GW until 2020, which also counts in relatively modestly sized plants in the Baltic Sea
TenneT, whose investments are refinanced by grid fee income that is collected from power consumers as part of their bills, plans to raise North Sea connection
capacity to 7.1 GW by the end of 2019 and to more than 10 GW by 2025.
Out of the 4.4 GW of existing capacity, between 1.5 GW and 2.6 GW had been producing in January through June, measured by monthly averages, but on June 7, a maximum level to date of 4 GW had been reached, it said.
Wind speeds at sea are higher than on land and growing capacity helped first-half 2017 production volumes in the North Sea - that vary depending on weather - rise to 7.8 terawatt hours (TWh), 50 percent up year-on-year, TenneT said.
Hardware and production costs in the offshore wind industry have fallen sharply, allowing shift from subsidies to an auction-based system, that will cut prices for consumers.
(Reporting by Vera Eckert; Editing by Edmund Blair)