* Industry builds ever bigger turbines in race to cut costs
* Biggest announced turbine so far is GE's 12 MW Haliade-X
* Graphic-Giant wind turbines: tmsnrt.rs/2rr299K
By Christoph Steitz
FRANKFURT, Sept 24 (Reuters) - Japanese-Danish joint venture MHI Vestas can scale up its current offshore wind turbine platform to match a 12 megawatt (MW) rival product that is being developed by General Electric (GE), its chief executive said.
The sector is racing to build ever larger turbines, which are becoming more efficient along with size. The most powerful offshore turbines currently in commercial use were built by MHI Vestas and have an output of 8.8 MW.
Rivals Senvion and Siemens Gamesa are both looking into double-digit MW offshore turbines for the next decade. Earlier this year, GE announced its 12 MW Haliade-X, to be launched in 2021, the biggest turbine to date.
"We believe that we can occupy the space of the competition with the current platform and the current incremental design that we are considering," MHI Vestas Chief Executive Philippe Kavafyan told Reuters.
"For us, the next step is beyond what is currently announced."
MHI Vestas is owned in equal shares by Japanese engineering group Mitsubishi Heavy Industries and Denmark's Vestas , the world's second-largest maker of wind turbines after Siemens Gamesa.
Kavafyan said that scaling up would be possible by adding larger rotors, reinforcing the torque and upgrading electrical systems, which would spare the group developing an expensive new machine.
The company has been able to produce a ramped up V164 platform with an output of 9.5 MW, which it will install for the first time next year, when Siemens Gamesa will bring its 8 MW turbine to the market.
"That gives us a roughly 1.5 MW advantage which translates directly into infrastructure savings. That's easily 15-20 percent," Kavafyan said.
Infrastructure costs such as building foundations or laying cables usually account for a third of the total cost of an offshore wind farm, which start from 1 billion euros ($1.2 billion). Turbines make up about 40 percent.
Offshore wind project developers such as Innogy and Orsted depend on falling costs as the industry is weaning off subsidies and must compete in public tenders for capacity where the lowest bids succeed.
"The biggest decision drivers are size and efficiency, cost and maintenance," according to Oskar Tijs, senior investment analyst at Dutch asset manager NN Investment Partners, one of Siemens Gamesa's top-10 shareholders.
"If GE gets its 12 MW turbine on the market, MHI Vestas and Siemens Gamesa would have to act." ($1 = 0.8499 euros)
Editing by Ed Osmond