A peculiar new approach to extracting renewable energy from the oceans has been deployed successfully, and it uses a method that might be familiar to many people. It copies the movement of a kite to transfer energy from tidal and ocean currents efficiently. And, it is currently providing electricity to the grid in the .
The power generator was designed by a company called Minesto from Sweden, whose focus is marine energy technology. Their tidal energy kite is no . It has a wingspan of 12 meters (39 feet) and weighs 28 tons. But the weight doesn’t matter underwater. The Dragon 12 – as it is called – has been deployed in a narrow channel between the islands and tethered to the sea floor.
The shape of the tidal kite allows for the repeated and consistent figure-of-eight movements that guarantee fast flow around the device. This flow spins a turbine, which generates electricity and transfers it through the tether and then to shore on cables across the sea floor. Dragon 12 is rated at 1.2 megawatts – Minesto has not released how much electricity it is providing to the roughly 55,000 inhabitants of the islands, but at the maximum rate it could cover the needs of about 1,000 homes.
“This is a big day for Minesto. We have reached the most significant milestone in the history of the company by producing electricity to the grid with our mega-watt scale powerplant. We are both proud and happy and more than ever look forward to the journey ahead,” Dr Martin Edlund, CEO of Minesto, said in a press .
“What the Minesto team has achieved today is extraordinary and set a new agenda for renewable energy build-out in many areas of the world. The competitiveness of the Dragon 12 is straight to the point; it’s powerful, cost-effective and feeds predictable electricity to the grid.”
The cost of tidal power generation with the Minesto setup seems to be significantly smaller than other and just a bit higher than the cost for . This might change with scale, and it might end up being a competitive alternative to offshore wind generation for two reasons.
One is that the tidal kite is much easier to deploy – it’s not a major engineering project. And, tidal currents happen with a certain regularity, unlike the variation experienced by the wind. It will be interesting to see the next steps for this technology.