Soaring with imagination

The first-ever study of high-altitude winds by the Carnegie Institution and California State University says winds in the jet stream, about 30,000 feet up, would be the ideal source to exploit. And how? Using kite-shaped turbines! These could meet world demand 100 times over.

The researchers found that the regions best suited for harvesting this energy match with population centers in the eastern U.S. and East Asia, where median values are greater than 10 kilowatts per square meter.

Using 28 years of data from the National Center for Environmental Prediction and the Department of Energy, the team compiled the first-ever global survey of wind energy available at high altitudes in the atmosphere.

The researchers assessed potential for wind power in terms of wind power density, which takes into account both wind speed and air density at different altitudes. To harness the huge amount of energy, one has to go to heights of 30,000 feet.

Jet streams shift seasonally, but otherwise are persistent features in the atmosphere. They are generally steadier and 10 times faster than winds near the ground, making them a potentially vast and dependable source of energy.

Using kite-like turbines, up to 40 megawatts of electricity could be generated by current designs and transmitted to the ground via the tether.

Some amount of fluctuation cannot be ruled out as even over the best areas, the wind can be expected to fail about five percent of the time. A global scale grid could be the solution.

Infrastructure is again the key challenge and the cost. Just as in the case of space based solar power. A detailed cost-benefit calculation could show if it is worth pursuing these flights of imagination.