A new sort of tidal energy device that looks like an underwater kite offers the promise of clean energy generation from low-velocity currents in the ocean.
Many tidal energy solutions require a location with higher velocity currents, or to be at or near the surface of the ocean, which limits their application, but the Deep Green device is said to be suitable for operating in deep waters with low velocity currents( 1-2.5 m/s), which greatly increases the number of possible locations.
Combining a tethered wing and a turbine, the Minesto Deep Green device “flies” underwater, using the ocean current to provide lift, while being attached to an anchor point on the sea bed. The kite then moves in a transverse direction to the current (controlled with a rudder), which increases its velocity to much higher than that of the actual current. This increase in velocity allows the turbine and generator attached to the device to harvest much more kinetic energy than is in the original flow, by up to a factor of ten.
The Deep Green device has a swivel attachment at the end of its tether, in order to “fly” it smoothly in a figure-8 or other pattern, and it sends the generated power down to the anchor on the ocean floor via cables in the tether.
The wing is neutrally buoyant while operating, but can the ballast can be controlled remotely, which allows it to be brought to the surface if necessary. According to Renewable Energy World, the Minesto device is lighter by a factor of 20 to 30 times less than other tidal energy devices (for high-velocity locations). This lighter weight would make it much simpler to install and handle with smaller boats and other equipment, cutting the expenses associated with operating them.
One Deep Green device is currently operating in a long-term sea trial in order to test and optimize the system, and the company hopes to have a 3MW array operating in 2015, and then scale that up to a 10MW array in 2016.
If you read this far, we assume you found this post interesting. Please help Blackle Mag thrive by sharing it using the social media buttons below.Tweet
What did you think of this post? Let us know in the comments below.