6. Wind Turbines, in the Sky

Introduction

 Since fossil fuels and non-renewable energy are becoming more and more scarce, an important topic in the engineering field is alternative energy sources. Especially those that are considered renewable. One source of renewable energy is wind energy harnessed by wind turbines. The main problem with traditional wind turbines are inconsistent winds and the space required to install a wind turbine. I came across a technology that addresses these issues. But, like many other technologies, it is not without its own problems.

Design Analysis

After watching the video, it is clear that there is potential for this type of technology to be a large contribution to renewable energy. One of the major issues with the proposed design above is that it uses helium to keep the system afloat. Looking into helium, it is becoming a scarce commodity itself. And thus, helium has become expensive. While these designers are heading in the right direction, I do not think the use of helium is a cost efficient design.

Design Considerations

There is a lot to consider when creating a floating wind turbine. Below is a list of a few points that one has to consider when creating a viable system:

1. Jet Streams - These turbines will have to be located strategically to fully harness jet streams
2. How to raise the system - How will the system rise into the sky? A few solutions are helium, a solid structure, a vertical turbine (like a helicopter), hot air, wind itself (like a kite)
3. How high to raise the system - This is a complicated question in itself. One has to raise it high enough to avoid the boundary layer between the earth and the atmosphere, but low enough not to escape the troposphere. As we raise higher, wind speeds increase but air density decreases. One would have to study the atmosphere to optimize these two aspects.
4. Weather - If one decides to raise it lower than the clouds, one would have to take into consideration the weather.
5. Air Traffic - Since these wind turbines are flying high into the atmosphere, a new problem arises where airplanes would have to avoid these areas in order to avoid collision.

Design Proposal

Below is a design proposal I made that addresses the problem of using helium. The system is far from perfect but could be a step closer to finding the best solution. The idea of the design is to launch a wind turbine into the sky, while tethered by a conductive wire on the ground. The balloon will be inflated from convection by a filament that is powered by the wind turbine itself. The purpose of the filament compared to a flame, much like the traditional hot air balloon, is to have the heat more controlled in a environment that contains high winds and low temperatures. The whole system would be fully sustainable because it is self powered and made with high quality material.

The material that contains the helium may be porous and helium would eventually leak through diffusion. This means that it would need to be re-inflated, and thus, periodic maintenance will be required. With this new design proposal, maintenance would not be as periodic as the helium balloon.

Helium Shortage

http://www.peakscientific.com/learn/articles-and-application-notes/availability-of-helium/

Helium Vs. Hydrogen

http://www.airships.net/helium-hydrogen-airships

Layers of Atmosphere

http://www.weather-climate.org.uk/02.php

Research and Design Proposal by Stanford University

http://news.stanford.edu/news/2009/june24/high-altitude-winds-062309.html