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.

How High Altitude Wind is advantageous

Any motion in nature if tapped properly can be converted in useful electricity. Now over here I have mathematically explained how , high altitude winds can be advantageous.

where:

 = speed of the wind at height 

 = gradient wind at gradient height 

 = exponential coefficient

The Hellmann exponent depends upon the coastal location and the shape of the terrain on the ground, and the stability of the air. Examples of values of the Hellmann exponent are given in the table below:

location	α
Unstable air above open water surface:	0.06
Neutral air above open water surface:	0.10
Unstable air above flat open coast:	0.11
Neutral air above flat open coast:	0.16
Stable air above open water surface:	0.27
Unstable air above human inhabited areas:	0.27
Neutral air above human inhabited areas:	0.34
Stable air above flat open coast:	0.40
Stable air above human inhabited areas:	0.60

Now look into the above equation. For example someone lives in human inhabited area where at a height of 3 meters, he is getting wind speeds of mere 2m/sec , if the wind is stable the exponential coefficient is α = 0.60, A few blogs earlier I have mentioned about Google's Makani High Altitude Wind power.

Now suppose we have the Makani system stationed in this highly populated area. The Makani Kite can reach heights of 310meteres. Suppose that the Makani Kite is raised upto a height of 300meteres. So what windspeed it gets at this height?

Lets calculate;:

                               0.60

V300=2*(300/3)

V300= 31.7 meteres/sec

So at high altitudes the windspeed is always likely to be very high, if this was unstable wind still the wind speed would have been approximately 8 m/s at a height of 300 meters.

So at high altitudes most of the times wind speeds are likely to be high most of the times in almost all the regions of the world. 

Google Makani and Alteros BAT taps into this and produces electricity and there is indeed a lot of electricity that can be produced this way. Saving us from tonnes and tonnes of carbon dioxide and greenhouse gas emissions. 

With so much work going into green energy research and renewable electricity technology the world can look into a greener cleaner future. 

Buoyant Air Turbine - BAT

       The above pics show the Alteros Buoyant Air Turbine that promises to provide cheaper wind power. It taps into winds at high altitudes where the wind speeds are much higher thus a BAT turbine would generate twice the power of a conventional turbine. 

         The setup consists of a shell , a turbine , teethers and a ground station. The shell is made up of high class durable plastic that is inflated with helium . This shell can also be used mount communication and camera equipment. 

       Within the shell you have the turbine which rotates with high speed winds and generates electricity. 

    Teethers connect the shell to winches on the portable ground station. 

       The benefit with this turbine is that it saves on costs of installation and transport by as much as 90%, it is twice as efficient as a traditional wind turbines. In places where there ground wind speeds are not good this turbine can also be used since at high altitudes of 1000 feet or more the wind speeds are good enough to generate electricity economically. Thus if such BAT s are installed in big numbers they can power the entire world and the great advantage is that it is totally green energy and renewable no need to burn any fossil fuel. 

        The BAT is designed to withstand windspeeds of 161 kmph +  . It requires no crew for day to day operation. The system can be monitored remotely and in case of extreme weather condition the system would autonomously dock.

     More information about Alteros BAT can be found at http://www.altaerosenergies.com

      Check out this video 

https://www.youtube.com/kldA4nWANA8