Tension leg platform

Tension leg platforms (TLPs) are wind turbines, or Oil Platforms, attached to floating platforms with steel cables tethered from the corners of the floating platform to a concrete-block or other mooring system on the ocean floor. As the platforms move from side to side in the water, energy is transferred through undersea cables. TLP's have been in use since the early 1980s. See Tension-leg platform.

The Massachusetts Institute of Technology and the National Renewable Energy Laboratory designed the first TLPs for offshore wind turbines in September 2006. Previous offshore wind turbines cost more to produce, stood on towers dug deep into the ocean floor, were only possible in depths of at most 50 feet, and generated 1.5 megawats for onshore units and 3.5 megawats for conventional offshore setups. On the other hand, TLP installation costs a third of previous offshore windmill tower installation, TLPs float, researchers estimate they can operate in depths between 100 and 650 feet and farther away from land, and they generate 5.0 megawatts. [http://www.livescience.com/technology/060918_floating_windmills.html Floating Ocean Windmills Designed to Generate More Power] ]

TLPs cost less to make and install because they are assembled onshore, are towed to their destination, and can be moved. Paul Sclavounos, an MIT professor of mechanical engineering and naval architecture who was involved in the design, said, "You don't pay anything to be buoyant."

Computer simulations project that in a hurricane TLPs would shift three to six feet and the turbine blades would cycle above wave peaks. MIT and NREL researchers say dampers could be used to reduce motion in the event of a natural disaster.

MIT and NREL researchers plan to install a half-scale prototype south of Cape Cod. Sclavounos said, "We'd have a little unit sitting out there to show that this thing can float and behave the way we're saying it will."

References