The altitude winds blowing in the troposphere represent an energy source that is larger than the world’s current energy needs.
Since 2010, Kitenergy has been innovating in the wind energy field with the introduction of high-technology, ultralight kites tethered to a ground-based generator by two ropes. Along their trajectories, the kites reach the upper part of the Planetary Boundary Layer, up to 600 m above ground level, where winds are stronger and more frequent than at the typical range of state-of-the-art windmills. The position and speed of our kites are continuously monitored at a high sample rate by the custom on-board avionic devices. Collected data is transmitted to the ground by a long range RF telemetry link. The flight control unit receives the data and, in real time, calculates the best trajectories to increase the power output while maintaining safe flight conditions. Simultaneously, instructions to steer the kite through continuous tether-length variation are sent to the industrial motion controller.
THE PHYSICAL PRINCIPLE
The kite’s aerodynamic forces, mechanically transmitted by each tether to its winch, act on the generators at ground, charging a storage system, feeding a local user or directly supplying electricity to the grid.
THE POWER OF HIGH-ALTITUDE WINDS
The kites can operate well over the 200 m limitations of windmill blades, reaching unexploited altitudes above the ground where stronger winds are blowing worldwide. This means higher amounts of yearly generated energy. Recent studies show that the wind power available at 800 m is about 4 times the power available at 80 m above ground. High-altitude wind has the largest energy per square meter (W/m²) among all the renewable energy technologies. Kitenergy can represent one or the only economically convenient solution in many sites where present wind power technology cannot grant the expected return of investments. Scarce wind resource, land or marine exclusion criteria, and complex logistics do not pose a limit anymore.
Islands and isolated communities
Farmyards and breeding farms in open landscapes
Remote areas contractors, such as mining and oil & gas
Kitenergy’s technology can achieve a higher power density than current wind-farm installations.
On a given site, as a function of wind variations in speed and direction, the energy produced by a wind generator at the nominal power in a single year is measured by its Capacity Factor (CF). In sites with high Suitability Index for wind turbines, Kitenergy technology can theoretically reach a capacity factor of up to 48%, exceeding the latest horizontal axis windmill performances. Considering its competitive total cost of installation and maintenance, the economic return with Kitenergy’s technology becomes higher. Such exceptional figures can be achieved on the basis of the increased flexibility in wind farm layout optimisation, such as the possibility of coordinating the wings’ flight at different altitudes, thus avoiding aerodynamic interference.
FLEXIBLE AND SUSTAINABLE ENERGY SOLUTIONS
The manufacturing and installation costs of a Kitenergy generator can be expected to be remarkably lower than those of a wind tower of the same rated power.
The key idea behind our technology is to efficiently harvest high-altitude wind energy by minimizing generator structure, cost and land occupation according to circular economy principles. The structure of a wind tower determines most of its cost and imposes a limit to the elevation that can be reached. Kitenergy replaces the steel tower with two high strength synthetic ropes and the thermoset composite blades with locally reinforced fabric kites. For example, in a 250 kW wind turbine, the weight of the rotor and the tower is typically about 50 metric tons. A Kitenergy generator of the same rated power can be powered by a 250 m² wing pulling two 1000 meter-long ropes, with a total weight of about 15 metric tons.
This technology has the potential of generating renewable energy, available in large quantities almost everywhere, with lower production costs than those of fossil energy.