The United States Department of Energy will fund six projects mostly into developing direct-drive wind turbine technology. Direct-drive generators eliminate the need for a gearbox, which reduces weight, eliminates moving parts, and reduces maintenance costs.
Increased component reliability means fewer operations and maintenance costs over the lifetime of a wind turbine, the department said.
United States energy secretary Steven Chu said six projects were selected to receive nearly $7.5 million over two years to advance next-generation designs for wind turbine drivetrains.
The grants will first be given as six-month Phase 1 funding where each project will receive up to $700,000 for holding technology cost and readiness assessments.
A succeeding second phase will choose from Phase 1 qualifiers, some of which could get up to an additional $2 million over 18 months. These projects will conduct performance tests of the specific drivetrain components.
Drivetrains include a wind turbine’s gearbox and generator, and are responsible for producing electricity from the rotation of the blades. A heavy unit, it is an expensive part of the wind turbine, which is why engineers are exploring direct-drive generator technologies.
Clipper Windpower will test a drivetrain using a chain drive to replace the gearbox, which enables increased serviceability and scalability to large capacity turbines.
But most of the projects in the funding category fall into direct-drive technology.
GE Global Research from New York will design and conduct component testing for a 10-megawatt direct-drive generator using low-temperature superconductivity technology which reduces the risk of fluid leakage.
Dehlsen Associates, L.L.C. will test components of a direct-drive design that can eliminate the need for gearboxes, power electronics, transformers, and rare earth materials, and which is also applicable to marine hydrokinetic or ocean power devices.
The National Renewable Energy Laboratory and Boulder Wind Power got funding for their projects in Colorado. N.R.E.L. will optimize a hybrid design that combines geared and direct-drives through an improved single-stage gearbox and a non-permanent magnet generator that reduces the need for rare earth materials. The technology is scalable to 10 MW and may be used to retrofit currently deployed 1.5-MW turbines.
Boulder Wind Power from Colorado will test a permanent, magnet-based direct-drive generator for a utility-scale turbine, which can operate at higher efficiencies than other permanent magnet generators.
Advanced Magnet Lab from Florida will develop a superconducting direct-drive generator for large wind turbines, which will employ a new technology for the drivetrain coil configuration to address technical challenges of large torque electric machines.
The United States aims to source 20 percent of its electricity needs from wind by 2030. A 2008 study by the energy department cites transmission, siting and permitting as the other areas which must be addressed to attain the target.