Wind turbine makers are aiming ever higher to get more power from the giant machines, building turbines that pack more of an electricity generating punch, as well as towers and blades that are just, well, bigger. But how big can the turbines get?
American Superconductor is going for a whopping 10 megawatts, more than twice the power of some of the bigger turbines in operation today. General Electric, one of the largest manufactures of wind turbines in the world, currently makes turbines ranging from 1.5 MW to 3.6 MW.
American Superconductor said this week that it will work with the Department of Energy’s National Renewable Energy Laboratory and its National Wind Technology Center to look at the economics of building a 10-MW turbine. The Devens, Mass.-based company said it can get a bigger power punch but still keep the size and weight under control by using its high temperature superconductor wire, which it claims is lighter and more efficient than the copper wire traditionally used in wind turbines.
Apparently even the economic downturn can’t stop these new turbines from spinning. Carpinteria, Calif.-based Clipper Windpower, which recently announced production cuts and layoffs, insisted to the Guardian that its work with the UK’s Crown Estate on a 7.5-MW offshore turbine, dubbed the Britannia project, is going full steam ahead. Clipper announced plans for the more powerful turbine last April, calling it the world’s largest offshore turbine.
But what about the growing physical size of these giants? The National Wind Technology Center is looking at that as well, saying earlier this month that it plans to install two big turbines at its lab just south of Boulder, Colo. The turbines, from GE and Siemens, don’t necessarily represent the largest turbines available, but they’ll be the largest ever installed at the wind center, giving scientists a chance to poke and prod the machines to see what kind of stresses the turbines can take. They plan to work on ways to get more power out of existing turbines, and on how to improve the durability of the turbine’s components.
The GE turbine, a 1.5-MW model of which is currently available, will have a 262-foot steel tower, with the diameter of the rotor reaching 250 feet. The whole thing weighs about 220 tons. The Siemens turbine, a late-stage prototype, will generate 2.3 MW, with a tower about the same height as GE’s, but a much bigger rotor, one that covers 331 feet.
Maybe we’ll have a better idea of how big these giants can be, or should be, when the wind center finishes its tests in late 2011.