Electricity from Kites

Makar Sankranti everyone knows about this day in India which falls on 14th January. This day is celebrated across the nation by flying kites millions and millions of them. This festival has been celebrated in India since times immemorial. The humble kite is known to people across the world and many among us have flown kites for fun.

But what if the same humble kite be modified and used for better purposes. To satisfy one of the most important needs of modern life electrical energy and at the same time not cause any pollution at all. Yes we have come to a time when researchers across the world have designed Kites that can generate electricity with the help of winds both in air and also under water using underwater waves.

For low water speeds less than 2.5 metres per second a Swedish company Minesto has developed a technology to generate electricity from underwater kites that can produce electricity. Water is 800 times denser than air and hence contains 800 times more energy. The Minesto Underwater Kites are tethered to the Ocean or river beds as shown in the picture. The rudder on the kites is controlled externally by the operators . Therefore the kites move along a controlled path. There is a gearless fast rotating turbine affixed to the kites that rotates along with the motion of the kites and generates electricity. The project is named deep green and has now 4 different products that are extensively tested one has 8 meteres wingspan and can generate 120 kilowatts of wind power at a stream velocity of 1.3 m/sec. The one with the largest wingspan Dg -14 has a wingspan of 14 metres and can generate power in tune of 850 kilowatts at a stream velocity of 1.73 m/sec. So this technology promises to be green and renewable source of energy. Ocean tides are predictable unlike Winds which are intermittent. You can get more information about the technology and the product form the this link .

In this video Link you can see how electricity can be generated using atmospheric kites. This technology developed at Delft University 

The other short video explains ho Dutch scientists have harness the power of kites to generate electricity. As seen in the video they used a 10 sq meter kite and raised it to a height of around 800 metres and generated 10 kilowatts of electricity. At this height the wind speed is higher than the wind speed on ground traditional wind turbine towers cannot reach such a height. 

   Now energy and speed has a cubic relationship. If the speed of wind is 5 m/sec at the height of wind turbines then the height at which this kite would rise it will have a speed of 7 m/sec. Thus approximately 4 times more energy can be generated at this height but it is not possible to have a wind tower that high. But kites can get to that height at a much lower cost. Scientists plant to create an array of such kites to generate many megawatts of electricity.

    So you see what was a source of fun to people when made better and when more thought and science is put into it has potentially become a solution to one of the most major problem on earth and that's totally clean and green energy.