Undersea kites generate tidal energy in Denmark’s Faroe Islands

The tide is high, but submerged kites off the shore of the Faroe Islands are holdin’ on.

The kites are part of the Faroe Islands Space Program, which consists of three kites connected to the seabed by subsea cables. Fitted with generators, the kites collect energy from the underwater currents and tides as they move in a figure 8 pattern. That energy then travels through the subsea cables to transformers on the shore of the Faroe Islands, an archipelago that’s a territory of Denmark.

The project is the brainchild of Minesto, a Swedish tidal energy company. When complete, the program will consist of six kites with infrastructure connected to the islands’ electrical grid, which will provide energy to locals. It’s dubbed the Faroe Islands Space Program because tides are considered a lunar resource.

“As long as the moon stays in its orbit,” Minesto CEO Martin Edlund told Tech Brew, “we are in production mode.”

That means tidal energy is an always-on renewable, or a baseload form of energy. The energy itself is kinetic, harvested from the intensity of water flow, and Minesto’s tidal technology can collect energy from low flow tides as well as higher, more powerful currents.

“We use the same principle as kite flying, but we do it submerged in the water,” Edlund said. “We fly on the linear movement of the ocean.”

Edlund said that the stable tidal conditions and high-tech electrical grid in the Faroe Islands were ideal for the technology, which is why Minesto set up shop there. Plus, the program is in line with the islands’ energy goals: Through tidal, wind, solar, and wave energy, the Faroe Islands hope to run on entirely renewable energy by 2030.

Altogether, tidal energy’s global generation capacity is 650 gigawatts, which is larger than that of nuclear energy. But it isn’t distributed equally, meaning that some locations—like the Faroe Islands and Alaska—are able to better benefit from the renewable source than others.

“With a resource that exists in Alaska, we could provide Alaska with all the electricity that’s needed,” Edlund said, by using approximately 500 of Minesto’s tidal kites.

Anti-friction: Minesto worked with SKF, an engineering company that specializes in anti-friction technology, to seal the kites to prevent salt water from entering the infrastructure. SFK’s materials also reduce friction along the machines’ surface, to prevent the newly generated energy from being lost to friction. And using vibration sensors, AI tools, and digital predictive technologies, SKF and Minesto simulated operating conditions to see how long different kite designs could function underwater while generating energy.

“You don’t have to do physical testing, then; you can do a lot of virtual testing that helps [Minesto] move faster in their design,” SKF’s chief technology officer, Annika Ölme, told Tech Brew. “Through the vibration pattern, you can say that this one is going to last for six years, or this one is only going to last for six months.”

Straight to the grid: Minesto is also partnering with SEV, the Faroe Islands’ electric utility, to put the tidal energy to use. Terji Nielsen, SEV’s head of research and development, told Tech Brew that the utility has entered into a power purchase agreement with Minesto to buy the energy created by the tidal kites. Tidal will be yet another clean energy that will help power the Faroe Islands’ grid, which received 57% of its energy from renewable sources last year.

“From [a] historical point of view, the Faroe Islands have exploited renewable resources [for] more than 100 years,” Nielsen told Tech Brew. “[We] have looked into tidal technologies for many years.”

And Minesto CEO Edlund said that the advances in deploying tidal are just the start of expanding the “toolbox” of renewables to help power grids globally.

“We have to add something that has unique characteristics,” he said. “The dream is to find more baseload renewables, such as tidal, and mature those technologies to make them commercially available.”