According to a study by the British oil company BP plc, coal-fired power plants accounted for 38 percent of global electricity production in 2017. Countries such as China and India, in particular, where energy requirements will continue to increase in the coming years due to economic developments, are building new coal-fired power plants despite climate change , thereby further increasing the CO2 emissions for energy supply .
Scientists have developed a flying wind power plant that rises to 500 meters. The power of the wind is about eight times higher than that of normal wind turbines. In the future, the kite could supply electricity to islands and remote areas.
Scientists from the Swiss Federal Laboratory for Materials Testing and Research (EMPA) have now presented an alternative to conventional fixed wind turbines, which consists of a kite that is connected to the ground with a thin rope. According to Rolf Luchsinger, the idea for this came from a kite that was exposed to wind power at high altitudes.
Use of the flying power plant in remote areas and islands:
As Luchsinger explains, “wind power is not for densely populated areas.” According to him, he sees possible uses of the kite in remote areas and on smaller islands . Currently, “the scientists speak to mines, remote settlements and islands as potential customers, where diesel generators are still in use today that generate exhaust gases and noise and whose fuel has to be delivered at great expense.”
In the long term, however, Luchsinger thinks even bigger and sees potential in using the technology in floating wind farms in the sea . In his opinion, the advantages are the almost unlimited space and the high wind speeds. The company is currently looking for partners from the energy industry and private investors for financing.
Wind power significantly higher at a height of 500 meters:
The researchers at EMPA involved in the project founded the company TwingTec in 2013, which develops the flying power plants and will later also commercialize them. In contrast to normal wind turbines, which reach a hub height of around 120 meters, the flying power plant rises to a height of around 500 meters and thus reaches winds that are about eight times stronger .
As it ascends, the kite moves in a circular path and pulls a tether from a reel, the rotation of which drives a generator. As soon as the kite has reached its maximum flight height, it sinks again and the rope is wound onto the reel. Then the cycle starts again. As Luchsinger explains, “the big challenge is not flying itself, but automated take-off and landing.”
30-minute practical test successfully carried out:
A prototype with rigid wings and flaps reminiscent of the control of an aircraft was successfully tested for 30 minutes in autumn 2018. The take-off and landing take place using small rotors, which are also used for drones . The span of the prototype T 28, which was started in Chasseral in western Switzerland, is three meters. The take-off from the base vehicle and the subsequent landing were carried out autonomously and without causing any damage to the flying power plant.
In the meantime, the next prototype T 29 has been completed, which can generate up to ten kilowatts of electrical power. In cooperation with the Bern power plants, the electricity generated by the kite should reach the consumer. If the prototype T 29 is also successfully tested, according to the developers, series production of the TT100 with a span of 15 meters can take place promptly. The maximum output of 100 kilowatts could supply around 60 single-family houses with electricity.
Vertical axis wind turbines
While most of the wind turbines known to us rotate about a single vertical axis, such as the Typhoon turbine , which we have already reported, vertical axis wind turbines (VAWTs) catch winds that move through the device. The rotation of such turbines is usually independent of the direction from which the wind is blowing. Therefore, they can be useful in areas where the winds are inconsistent.
So far, there is no established technology that is able to use the relatively chaotic winds of the urban environment effectively. The prototype of the O-Wind turbine seems to be a step further than other VAWT concepts. The design focuses on a spherical shape to take advantage of Bernoulli’s law and has openings that run across the surface so that winds from all directions can rotate the ball around its vertical axis.
Will it work?
It is still unclear how much power the O-Wind turbines can actually produce. The turbines are currently not designed for large capacities and are primarily intended to produce electricity on the balcony or on buildings. However, the design must also improve significantly compared to the relatively low efficiencies of other VAWT designs.
It would be surprising if the 25 cm diameter turbine produced a lot more than 100 watts compared to other devices on the market. But the project is still at an early stage and it is quite possible that enlargement will lead to sufficiently large yields.
What is in the design:
In their design, the inventors were inspired by NASA ‘s ” Tumbleweed Rover” – a kind of inflatable ball that should roll over the surface of Mars and compare conditions in different geographic locations. With a very low attraction and only one percent of the air pressure compared to Earth, this is not a trivial problem.
The student team hopes to be less than five years away from production. The prototypes are currently in wind tunnel tests at Lancashire University. The team is committed to using only sustainable materials such as recycled plastics for its wind turbines in order to reduce costs to a minimum. The design could also work well underwater in the area of wave power generation, where water currents are as chaotic and strong as urban winds.
The invention of the duo won the international James Dyson Award in November 2018.