Continuous upper atmosphere winds in excess of 200 mph contain 100 times the energy used yearly by humans. Innovators, engineers, atmospheric scientists and entrepreneurs believe that huge kite-like wind-power generators could easily and very affordably provide all the energy needed to power our planet.
And just imagine all the jobs that will be created.
Jet streams are quick moving upper air currents flowing continuously from west to east. Polar jet streams are stronger than subtropical jet streams, and they both occur in each hemisphere ranging in altitude from about four to 10 miles above Earth's surface.
In 1752 Benjamin Franklin -- a Founding Father, scientist, printer, inventor, author, musician, civic activist, statesman, diplomat and economist -- undertook a series of electrical experiments using a kite to prove that lightning was a stream of electrified plasma. Kites have intrigued humans ever since. In fact, today the race to capture wind-power using a variety of kite-like designs is poised to revolutionize society offering yet another feasible green energy alternative to coal.
The technological design that first caught my eye was that pioneered by Australian engineer Dr. Bryan Roberts, co-founder of Sky WindPower Corporation. In 2008 Time magazine listed their airborne windpower as one of the best 50 designs of the year.
So how does it work?
Helicopter-styled wind turbines are made of carbon fiber, aluminum and fiberglass, weighing about 45,000 pounds. Massive 130-foot diameter rotors both generate electricity and control the movement of these gigantic kites. The kite is attached by a three-inch tether, which is controlled by a winch at the ground station. Insulated by special aluminum filaments and a core of Vectran (advanced composite materials used by NASA's spacesuit) the tether conducts up to 20,000 volts.
Sky WindPower dubbed their huge kites -- Flying Electrical Generators (FEGs). They lift-off using the same aerodynamic principle that inspired helicopters; that is, the engineering principles used by bumblebees. Reverse-pitch semi-rotary blades lift FEGs upward from electricity supplied from the ground station. Once it reaches the jet stream it adjusts its rotors producing less lift but more torque allowing the switchover to begin spinning giant turbines, making electricity and sending it down the tether into a utility grid. On-board computers enable this splendid invention to seek the optimal jet stream winds and adjust vertical stabilizers to maximize wind turbine capacity.
With an average wind speed of 200 mph, 300 FEGs each generating 20 megawatts linked to a utility grid could easily power Los Angeles. Sky WindPower estimates that its FEGs can produce electricity for between $0.01 and $0.02 per KWh, which is lower than the current price of non-subsidized electricity.
Ocean wave farms, kite jet stream farms, offshore wind farms, an array of advanced solar farms, geothermal or underground steam energy and other green innovations are clearly beginning to create jobs and assist our species in a remarkable new era as we have entered the Age of Energy Transformation.
Worldwide investments in green energies exceeded $257 billion for 2011, up from 17 percent from the previous year. Last week, Energy Secretary Dr. Steven Chu announced $10 million in prizes for teams that invented the most affordable rooftop solar power model for the U.S. market.
This is a time of change. It is important for each of us to remind ourselves that change is, in fact, opportunity in disguise.
Earth Dr Reese Halter is an award-winning science communicator, distinguished conservation biologist and author of The Incomparable Honeybee and The Insatiable Bark Beetle.
Follow Dr. Reese Halter on Twitter: www.twitter.com/DrReeseHalter
Undersea turbines are expensive enough without adding dams too.
High-density, low-speed flows push a lot, but don't yield much energy per unit structural price. Thus windmills are much cheaper than watermills.
http://www.hammerfeststrom.com/, http://www.marineturbines.com/
But... you have to fly a huge turbine into the sky, and place it in the jetstream, which means you have to keep driving N and S by five hundred miles, and need a mobile hook up point to the grid.
Let's say your kite has a 50-m diameter turbine and so produces ~10MW. The tension in the rope is going to be something like 50 tons, and the weight of 20-km of 50-ton-breaking cable is going to 50 tons too. That's getting bigger than a 737, and is going to cost well over $100m.
So, overall, it doesn't seem like a very viable idea.