There is a lot of sky, but little sun. Lots of wind, but little land. If you were a resident of the Faroe Islands, how would you obtain energy from renewable energy plants? You will never have the right answer: you were never Vikings. They do. And in fact the answer they give is:
With sea dragons.
The movement of the tides is the focus of a kinetic energy device called Sea Dragon. They are underwater kites or gliders with a wingspan of nearly 5 meters (16 feet) and swim in the tides in "squadrons" of eight at a time in 40 meters of depth, generating enough the energy to power 50-70 houses at a time.
The Faroe Islands, with just 50.000 inhabitants, are an autonomous Danish archipelago located between Iceland and Shetland. It would seem like a simple place to reach a zero emissions goal. It is not so.
With a North Atlantic climate and little land to build wind turbines, hydroelectric power provides over 40% of the island's energy supplies.
È Minnesota, a spin-off of parent company and (former) car maker Saab, to have developed these “tidal kites,” which work by using the lifting power of the tide a bit like an airplane.
How the Sea Dragons of the Faroe Islands work
The kite it's direct by a control system and rudders while anchored to the seabed by a cable, with the turbine experiencing a flow of water many times greater than the actual speed of movement.
The turbine transfers the energy to the generator, which transmits the electricity through a wire to a ground station.
Tidal kites operate in tandem with the marine environment in predictable ways and have minimal environmental effect, even on small islands like the Faroes where there isn't much land except to host the "receiving station."
A world kite
“The new kites will have a range of 12 meters and each can produce 1,2 megawatts of energy, the equivalent of a tenth of the country's current electricity demand,” according to Martin Edlund, CEO of Minesto. It's not bad, but hunger comes with eating: and one would never want to stop playing with kites.
The return to winter, Edlund says, was eye-opening. After an unusually windless summer in which the Faroes had to import far more diesel than they expected after installing wind turbines, the regularity of the tide was incredible. So much so that Minesto now wants to export the system: the Sea Dragons, the company claims, could provide 600 gigawatts of low-impact, low-cost renewable energy worldwide if produced in large numbers.
How about?
