Swedish engineering firm Minesto has deployed underwater “planes” that generate electricity. These planes are already working hard under the Faroe Islands in Denmark.
These machines look just like regular aircraft, but they are actually high-tech tidal turbines that produce electricity from the tides of the ocean. Minesto also calls them “sea dragons” or “tidal kites”.
The Swedish engineers have deployed two sea dragons so far with a 5-meter wingspan. They patrol underwater in a figure of eight pattern and are tied to the fjord seabed with a 40-meter metal cable. They absorb energy from a running tide just like a regular turbine.
A single turbine can produce enough electricity to power four to five houses.
They rely on the water flow for their movement, just like airplanes rely on the airflow over their wings. However, a sea dragon’s moving “flight path” allows them to cover a large area at much higher speeds than the underwater current. This way they are able to amplify the electric energy produced.
The seaplanes are steered into a water current using onboard computers and then they idle in still water, maintaining a constant depth on the water column. If there are several sea dragons in the same waters, then they are spaced apart to avoid collisions.
The generated electricity is sent back through the tethering metal cables to nearby onshore control stations. The seaplanes are already contributing energy to Faroe’s electricity company SEV.
Minesto’s CEO Martin Edlund has said they will deploy larger-scale sea dragons in the fjord by 2022.
The new kites will have a 12-metre wingspan, and each will generate 1.2 megawatts of power. We believe an array of these Dragon-class kites will produce enough electricity to power half of the households in the Faroes.