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 get energy from renewable plants? You will never have the right answer: you were never Vikings, you. They do. And in fact the answer they give them is:
With sea dragons.
The movement of the tides is the focus of a kinetic energy device called the Sea Dragon. They are underwater kites or gliders with a wingspan of nearly 5 meters (16 feet) and swim in the tides in eight-at-a-time "squadrons" at a depth of 40 meters, generating enough the energy to power 50-70 houses at a time.
The Faroe Islands, with only 50.000 inhabitants, are an autonomous Danish archipelago that lies between Iceland and the Shetlands. It would seem like a simple place to reach a zero emissions target. It is not so.
With the North Atlantic climate and little land to build wind turbines, it is hydroelectricity that provides over 40% of the island's energy supplies.
È Minnesota, a spin-off from parent company and (former) carmaker Saab, who developed these "tidal kites," which operate using the lifting power of the tide somewhat like an airplane.
How the Sea Dragons of the Faroe Islands work
The kite it's direct from a control system and rudders while anchored to the sea floor by a cable, with the turbine experiencing a flow of water many times greater than the actual speed of movement.
The turbine transfers energy to the generator, which transmits 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 other than to house the "receiving station".
A world kite
"The new kites will have a range of 12 meters and each can produce 1,2 megawatts of power, the equivalent of one-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 enlightening. After an unusually windless summer in which the Faroers had to import far more diesel than they expected after installing wind turbines, the regularity of the tide was incredible. To the point that Minesto now wants to export the system: the Sea Dragons, the company claims, could supply 600 gigawatts of low-impact, low-cost renewable energy worldwide if produced in large numbers.
How about?
