Green technology: Inside an advanced wind turbine

Innovative drivetrain technology is making it easier to get power from the wind. Back in the ancient times of 10 or 15 years ago, it wasn’t unusual for wind turbines to generate power in the range of tens or hundreds of kilowatts. Compared to the power levels found on the utility grid, this puny generating capacity almost made individual turbines an afterthought. Utilities didn’t have to worry much about grid operations being interrupted by problems at a wind farm. But wind farms are getting bigger. The next generation of multi-megawatt- scale turbines start to look less like quaint curiosities and more like regular power plants. That also means the wind turbines now coming off the drawing boards must have the same kind of reliability and safeguards as conventional power plants. Their economics must be in the same ballpark as well. The latter point is important because since about 2002, the cost of wind-powered electricity has not declined. To that end, wind-turbine designers are striving to come up with designs that are both more economical and reliable. and its Liberty turbine. The Liberty sports innovations that include a distributed generation drivetrain design (dubbed the Quantum Drive) and high-efficiency, permanent- magnet generators. These pair up with a sophisticated control system that adjusts both rotor blades and generator operation to squeeze power even out of light breezes. The Liberty design also incorporates ideas aimed at simplifying the maintenance of wind farms. For example, many of its components are light enough to be winched up its tower rather than be manhandled by a mobile crane. The meat and potatoes of a wind turbine are its rotor, gearbox, and generator. Liberty’s major drivetrain components illustrate some of the directions in which windturbine development is progressing today. The gearbox cranks up the rotational speed that the wind