Green Energy from Energy Kites

Today is January 6,2016. Eight days from now, on January 14th, the festival of Makarsankranti will be celebrated across India. In this festival kites are flown across the nation. The sky is filled with kites of different colors. But this simple kite, that has been flown by people for centuries for recreation and sport has a potential to change the world. However the kites that I am talking about are going to be more advanced than the kites that are used on Makarsankranti.

Kites fly by harnessing the power of winds. Earth is covered with a gaseous layer known as the atmosphere. Due to pressure variation in different parts of the atmosphere, air flows from an area of higher pressure to an area of lower pressure. This is flow if air is known as wind.

The speed of Wind varies at different places on the surface of earth. Wind has been utilized for a long period of time as a source of energy. In ancient times Europeans used windmills to grind wheat and lift water from wells. After dynamos and electric generators were made, engineers and scientists realized that the windmills can be used for electricity generation as well. So many windmill towers were set up for energy generation. The windmills started getting taller to harness more and more energy. However it is not possible to economically generate wind energy from every part of the planet.

Setting up the wind tower involved huge initial costs. Also there is a limit to how high a tower can go. Now, it is a well known fact that the higher we go, the speed of wind increases and that is the reason why windmill towers were made taller to generate more and more energy.

However engineers and scientists have come up with more cost effective ways of generating electricity using the power of wind. They are trying to tap into the power of high altitude winds using kites, that can rise up to heights of 800 - 1000 meters. At this heights wind speeds are high enough for economical generation of electricity almost everywhere in the world.

In this blog I have already discussed technologies that are focused on harnessing the power of high altitude wind like Alteros BAT(Buoyant Airborne Turbine) and Google Makani kites. However they are not the only ones who are trying to tap into the energy provided by High Altitude Winds there are others as well here is one more :-

The energy kites don't require any expensive and heavy tower, so the amount of material needed for construction of such energy kites is way less than that of a wind tower. The energy obtained from such energy kites will be very cheap.

In the 50s,60s and 70s arrogant things were said, like "Pollution is the price that humanity has to pay for development". We know today that it is not true. There far more green energy available in nature than the polluting energy from fossil fuel. 

Many countries are forced to support oil rich Middle East nations because of their need of oil. This technology can liberate nations from such dependence. There is enough energy nature has provided for all, only thing we need to learn is to tap it economically.

Makani Airborne Wind Turbine - Kite powered Electricity

High altitude winds has enough energy to power the world many times over. In this blog in the past I have mentioned about Alteros BAT and Kite Powered Electricity. Two years ago Google acquired a company called Makani Power .

The company is a green energy company that has built high altitude energy kites that can tap into the energy provided by high altitude winds to generate electricity. The advantage of using a kite to generate electricity is that one saves on cost of transportation of equipments required for setting up a wind energy tower and also the cost of setting up a wind tower with wind turbine is very high. 

While a wind tower can go up to the  the height of 120 metres. The Makani wind energy kites with a strong flexible teether can achieve a height of 80 to 350 meters. It is way cheaper than a wind turbine as no tower has to be built. Since these kites are aerodynamic they can access stronger winds and that is why every individual kite can generate 50% more energy. 

A single kite can produce upto 600 kW of energy at a wind speed of 11.5 m/sec. The system begins to generate power at a wind speed 4 m/s. At a height of 250 meteres such wind speeds are achieved very easily. 

More information about the revolutionary technology  can be obtained from this site http://www.google.com/makani .

The following video shows how the system works 

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.