A peculiar new approach to extracting renewable energy from the oceans has been successfully deployed, 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. Currently, it is providing electricity to the grid in the Faroe Islands.
The power generator was designed by a company called Minesto from Sweden, whose focus is marine energy technology. Their tidal energy kite has a wingspan of 12 meters (39 feet) and weighs 28 tons. Branded as the Dragon 12, it has been deployed in a narrow channel between the islands and tethered to the sea floor.
The shape of the tidal kite allows for 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 and could cover the needs of about 1,000 homes.
According to Dr. Martin Edlund, CEO of Minesto, electricity production to the grid by their mega-watt scale power plant marks a significant milestone and sets a new agenda for renewable energy build-out in many areas of the world. The competitiveness of the Dragon 12 is due to its power, cost-effectiveness, and predictability at supplying electricity to the grid.
The cost of tidal power generation with the Minesto setup is significantly smaller than other tidal projects and just a bit higher than the cost for offshore wind turbines. This may change with scale and end up being a competitive alternative to offshore wind generation due to the ease of deployment and regularity of tidal currents. The next steps for this technology will certainly be interesting to follow.