Flying a kite for clean energy
Wind turbines are a wonderful invention, producing clean energy from an abundant natural resource: the wind. Since the oil crisis in the 1970s, we’ve continuously developed new and more efficient wind turbines. Key to an efficient wind turbine is a steady flow of… you guessed it, wind. The higher in the sky, the stronger and more constant the wind. This poses a challenge as it requires us to build quite tall wind turbines to reach this “sweet spot”.
Or, we can fly there.
That is what Ampyx Power does. Ampyx Power has developed a Powerplane, which in terms of technology is basically a flying wind turbine, but looks a lot like a plane attached to a string. It’s a kite really.
The Powerplane is outfitted with an auto-pilot and is attached to a generator on the ground. The software ensure that the plane can fly completely autonomously while responding to changes indicated by sensors within milliseconds, allowing the plane to continuously fly in a figure-eight pattern. This figure is important. Flying across the wind accelerates the system and enables it to extract more power. As Ampyx Power explains it:
“A simple illustration of this phenomenon is to consider the movement of a water skier which enables them to overtake their tow boat. When the skier is behind the boat, the two travel at the same speed. However, if the water skier moves in a 'slalom', they travel faster than the boat. Similarly, flying a cross wind pattern means the system can go faster than the wind speed, which results in a significantly higher energy yield.”
The Powerplane can go as high as 450 meters – slightly higher than the Eiffel Tower and slightly lower than the Empire State building.
Their prototype plane has a wingspan of 5,5 meters, and can produce up to 50kW, supplying about thirty households with energy. The commercial Powerplanes have a much larger wingspan (30 to 40 meters) and can generate up to 2MW of power and supply 2000 homes with energy.
Material and installation costs are relatively low compared to wind turbines and these costs will go further down as they are able to scale up the business.
In 2013, Wolbert Allaart won the runner-up prize for Ampyx Power in the Postcode Lottery Green Challenge competition. The prize money allowed Ampyx Power to continue its technology development efforts and they have created two new prototypes with new functionalities, including the ability to fly 24/7. Ampyx' team now exceeds 20 exceptional engineers, scientists and business developers.
Source: The Optimist