The announcement at the WindEurope Offshore 2019 event comes one day after Siemens Gamesa revealed that its Direct Drive Flex turbines could now be dialed up to 11 megawatts.

The Hollandse Kust Zuid (HKZ) 1 & 2 projects, developed by Sweden's Vattenfall, will use an estimated 140 turbines off the Dutch coast, for a total project size of up to 1.5 gigawatts. Vattenfall had previously settled on SGRE's 10-megawatt turbines for the development.

The first two HKZ projects were awarded under the Netherlands’ tender in 2018 after Vattenfall made a bid with no subsidies attached. In July this year, Vattenfall won the follow-on tender for HKZ 3 & 4, again without any subsidy.

Under the terms of the tender, Vattenfall has five years to finalize construction of the Dutch projects, meaning the first HKZ projects are expected to be up and running in summer 2023.

The Dutch tenders do not include the cost of transmission, which is borne by the system operator rather than the developer, as it is in many markets including the U.K.

"Delivering clean energy for generations to come at a low levelized cost of energy (LCOE) is a joint target which we’re committed to achieving together,” said Andreas Nauen, CEO of Siemens Gamesa's offshore unit, in a statement.

In an interview, Kasper Yttesen, senior vice president at Siemens Gamesa Renewable Energy, said he wouldn’t like to guess how big turbines will eventually get.

“We haven't seen the end yet. There will definitely be bigger turbines,” he told GTM at the event in Copenhagen. One potential bottleneck for larger turbines is the availability of installation vessels. Yttesen said Siemens Gamesa had specifically kept weight in mind as it has moved its own turbines up the size chart. “We can’t just go with a big turbine [design] that is not really suitable within the supply chain. I think we are very cautious about that so when we develop our turbines and upgrades, they fit into the into the current market, whether it's the [supply] of key components or whether it's the vessel market." GE Renewable Energy made up some ground in the offshore turbine race this year when it secured two huge orders from Ørsted and SSE for its 12-megawatt Haliade-X machine. The orders total 4.8 gigawatts. In a recent press statement , Shimeng Yang, senior research analyst at Wood Mackenzie, said the industry is offering up some indications on future sizes. “Offshore wind turbine sizes are expected to reach 20 megawatts in the next 10 years. Leading Western developers have already filed permits to use a 20-megawatt turbine for projects in the U.K. and Sweden,” Yang said.

COPENHAGEN — Siemens Gamesa’s newly launched 11-megawatt turbines will be used for Europe’s first subsidy-free offshore wind farm.