'Underwater kite' aims to turn energy tide

London, England (CNN) -- A new type of tidal turbine which its creators describe as an "underwater kite" has taken a step closer to becoming commercially available.

STORY HIGHLIGHTS

New tidal-energy device "Deep Green" aims to keep energy supplies afloat
Underwater kite has recently received new financial backing and will begin tests in 2011
Device spans 12 meters and will be tethered to the ocean floor

Collected from: 'Underwater kite' aims to turn energy tide - CNN.com

Minesto contributes a solution to the worldwide energy demand by offering a unique technology that explores the vast, renewable and abundant ocean power resource.

Minesto develops a new concept for tidal power plants called Deep Green. Deep Green is based on a fundamentally new principle for electricity generation from tidal currents. The power plant is applicable in areas where no other known technology can operate cost effectively due to its unique ability to operate in low velocities. Minesto expands the total marine energy potential and offers a step change in cost for tidal energy.
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Deep Green

The kite consists of a wing, which is provided with a turbine and a generator, attached to the seabed by a tether. Hydrodynamic forces on the kite caused by the current velocity makes the kite to move and by a control system it is taken in a certain trajectory. The speed of the kite determines the flow velocity to the turbine, which is increased by about ten times the current speed. The electricity is transmitted onshore through a power cable inside the tether. With a wing span of 12 m the kite is designed to run at a speed of 16 m/s at a current velocity around 1.6 m/s. Animated movie.

Comparison

	Deep Green	Other Tidal Technologies	Off-shore Wind
Rated Power:	0.5 MW	1 MW	2 MW
Weight/Effect:	14 tonnes/MW	50-600 tonnes/MW	>200 tonnes/MW
Mean Velocity:	1.6 m/s	2.5 m/s	8 m/s
Cost/KWh:	€0.06-0.14	€0.15-0.30	€0.10-0.12