The wind generators of the future may fly over your head. Not like the huge blades of today’s turbines, but in the most literal sense of the word. kitecraft, one startup based in Munich, is working on a new electricity generation system based on an old acquaintance of the wind: kites. Of course, not the conventional ones. German engineers have developed a small light aircraft fixed to a ground base via a cable, a solution that is partly reminiscent of the one proposed by Makani and that came to capture the interest of Google.
His device is made up of an extruded aluminum structure with wings and tail, four pairs of carbon fiber motors and rotors, and a belt. At least on paper, its operation is relatively simple: just like a drone, the “kite” uses motors to take off and land and has a control unit to stabilize itself. Once in the air, where he draws “eights”, his devices are used as generators. Power is transmitted through the belt to a ground stationfrom where it is distributed to the network or directly stored.
The “simplicity” of the system —at least as far as deployment and resources are concerned— is one of the advantages that Kitekraft highlights over conventional wind turbine plants. “Instead of a huge rigid tower and blades, we use a small tethered plane to harvest wind power. With just a fraction of the materials, we can provide low-cost electricity,” he highlights.
Less logistics and less impact
To be more precise, the company estimates that its system requires approximately ten times less construction material than conventional wind turbines. For smaller devices, he says, you don’t even need a concrete base. Another advantage of Kitekraft is that it considerably simplifies logistics and maintenance.
“It enables our technology to provide low-cost, utility-scale, small-scale wind power and even lower cost at megawatt scale,” he says.
Beyond the logistical advantages, the saving of materials or the possibility of generating wind energy by lowering the bill, the startup points to strengths of another type: environmental. “Can reduce carbon footprint of wind energy by 90%; a flying wind turbine requires only a fraction of the materials compared to conventional wind turbines, but it has the same useful life”, he argues on his website, where he includes videos with his tests.
The small dimensions of the systems, which have little to do with the huge towers of conventional wind turbines, would also reduce the impact on the landscape. Their smaller weight and size also make it easier to deploy them in places where it would be very difficult to move large wind turbines and, in the event of tornadoes, to retract them relatively easily.
Today Kitekraft’s device is still a prototype, but the company hopes to have its first product, a kite, by 2024. 100 kilowatts with a wingspan of ten meters. Next, they point to Interesting Engineering, it would be a 500-kilowatt device with a wingspan of 20 meters. “Doubling the wing would not only double the power, it would give you five times more,” says Florian Bauer, co-executive director and chief technology officer of the German company, which is also “analyzing” the possibility of installing kite parks both on the ground and in the air. sea.
Not everything is advantages or strengths in the way of Kitekraft. As Bauer himself acknowledges, polishing the kite system with generators will not be easy. “Comparatively, the wind turbine is much simpler: it’s just a tower. One needs to understand all the technology to build the kite. Many of our competitors have been trying to solve the problems for years. There are various technologies and business hurdles,” he says. to Interesting Engineering.
A similar path —although with variants— has been undertaken by other firms, such as Kitepower, Kitemill or Airseas or SkySails Power, which works with large kites and has already deployed its system on the beaches of Mauritius at the end of last year. Also Makani Technologies, whose proposal managed to capture the attention of Google. Perhaps the best proof of the difficulties that the system must face is the declaration of the technological multinational itself when it abandoned the project, in 2020: “The path to commercialization is longer and riskier than expected“.
One of the challenges that the German firm has ahead of it is, for example, to scale its device, especially if it wants its devices to be larger, have more power and work efficiently at 300 meters, the heights where the winds tend to be more powerful.
Images | Kitekraft
George is Digismak’s reported cum editor with 13 years of experience in Journalism