German startup Kitekraft is developing flying wind turbines that require 10 times less materials to develop than traditional wind turbines. The company just announced successful flight tests, which it describes as a "major milestone towards our first 100kW product."
On its website, Kitekraft explains that the reduced requirement for materials for its flying turbine — which uses a tether instead of a huge tower — means it can reduce the costs of its energy to almost half of that produced by traditional wind farms at megawatt scale. Its carbon footprint is also lower than that of standard wind turbines, the company says, partially due to the fact that large wind turbine towers are typically transported by road.
Efficient renewable energy with a fraction of the infrastructure
To achieve its goals, Kitekraft, which recently completed a stay at tech accelerator Y Combinator, developed an autonomous hybrid kite aircraft that generates energy via eight small onboard rotors. The energy produced by the aircraft is sent down a tether to a ground station that is attached to the grid. Kitekraft's creators say their prototype generates the same energy as the tips of large wind turbine blades — the fastest-moving part of the blade — with a fraction of the required infrastructure.
In an interview with FastCompany last year, Kitekraft co-CEO Florian Bauer also explained that the technology can also be adapted to be used offshore. "You just need a ground station for the kite like a floating buoy," he said. "There’s no foundation required, like a huge tower that goes to the seafloor." If winds ever get too strong, the kites can simply be lowered to prevent any damage to the machines. Footage from the company's recent test flights can be viewed below.
Kitekfraft aims to increase its test flight frequency
Following the company's autonomous flight tests last month, Kitekfraft's other co-founder, Max Isensee, said "we are continuing our steps toward the final product design." The tests mean that several new systems, including a custom-designed high-lift multi-element airfoil, a magnet-based wind vane, and industrial Linux flight control computers are now flight-proven. Isensee explained that the company can now increase its test flight frequency and that, "in the coming weeks, further hardware and software improvements, as well as flight tests, are scheduled to further push the envelope."
To begin with, Kitefraft aims to deploy its machines on microgrids of remote islands, where transporting massive wind farm infrastructure and other renewable energy systems is not feasible. Its machines are also less of an eyesore — they are barely visible from a distance — meaning they could also be tested in communities that have pushed back against large wind farm proposals.
In a blog post from September 2020, Bauer said that Kitekraft was taking up the mantle of another firm called Makani. Makani had worked on a now-discontinued flying turbine project and it decided to release thousands of pages of technical documents as open source resources once it decided to no longer pursue its development of the technology. As Bauer put it at the time, this is a "testament to the mission-driven" nature of the work being carried out by companies such as Makani and now Kitekraft.