Can drones become equipment of wind power as well? European energy company E.ON plans to initiate the airborne wind energy system (AWES) Ampyx Power in 2020, and claims that its power generation efficiency precedes to that of existing large wind turbines. So how far along has it been developed?
The most common wind power in the existing market is generated through the large fan-like trefoil wind turbines situating on enormous pillars that tower on the land or sea, where aerodynamic energy is converted into mechanical energy, though such technology exposes an obvious disadvantage, as it requires bigger wind turbine to intercept faster and stronger wind, which then further increases the costs in materials, transportation, construction, and maintenance.
That is when AWES came into being, a system that is built on the concept of “kite flying”, and uses a drone in mid-air to spur the power generator on the ground to generate power. Take the Ampyx Power system in the Netherlands for example; a drone is connected with the cables of a ground generator, then ascends to about 200-450m above ground through auto pilot, where it flies in an orbit that is in the shape of the number 8, and the cable is constantly being pulled during the flight in order to generate power at the generator.
When the 750m long cable is fully pulled, the drone automatically descends to allow the winch to retrieve the cable, before ascending to the sky again, which sounds like a significant decrease in cost compared to existing wind power generation. Ampyx Power expressed that compared to the traditional trefoil wind turbines, this technology generates more power at merely 1/10 of required materials, and that depleted wind turbines can be seamlessly replaced with the AWES technology upon replacement.
Ampyx Power has now been subsidized by the Navigation Innovation and Support Programme of the European Space Agency (ESA), and strives to “take off” officially one day. At the same time, NAVISP and UK-based Omnisense are also developing a high-precision navigation system for this system.
As the name suggests, drones are operated without any human pilots, and a meticulous control of the drone’s location is a must, otherwise the take-off and landing of the drone will lead to another type of air disaster. Just as pointed out by ESA, a precise take-off and landing control is essential as it guides the drone safely back to the ground upon the need of inspection or maintenance. In addition, the landing platform is usually smaller than the wingspan of a drone, and there are times when a drone must land on a sea surface or rugged terrain, which further intensifies the difficulty in drone flying.
Furthermore, the new system can still operate despite interruption in satellite navigation, where the drone flies within a radius of 1km through ultra wideband (UWB), and is able to update its location in merely 1/100 seconds with a precision of 10cm.
Countless obstacles have been encountered on the path of realizing AWES, though it is not a lonesome journey. TwingTec, a spin-off company from the Swiss Federal Laboratories for Materials Science and Technology (EMPA), as well as University Carlos III of Madrid (UC3M), are both researching and developing airborne wind power technology. Although there are differences in the materials for the drone body, the concept is similar.
Nonetheless, there have been stragglers along the journey. The kite power generation program by Makani, a subsidiary of Alphabet that graduated from Google X, took way too long on the process of commercialization, and forced Alphabet to let go of it at the end.
(Cover Photo Source: ESA)