Renewable, sustainable, affordable energy—a goal humankind has sought for centuries—is no longer just a desire but an urgent need.
IEET as an organization and readers of this blog are especially interested in cutting edge research and development for new ways of obtaining clean abundant energy sources. But although we look forward to the day when massive solar collectors in space will beam effectively unlimited and nearly-free power to Earth, or when cold fusion can finally be achieved (if ever), we also need to be looking for solutions in the near-term that will help wean the world from our addiction to oil and our growing dependence on coal.
Not only are both of those energy sources strictly limited, our profligate overuse of them pours so much CO2 into the atmosphere that we are essentially setting fire to our only home while forgetting that we have no escape routes from it.
So, the need to look for replacement forms of energy generation that will at least slow and preferably cease our society’s carbon input to the environment is now recognized the scientific community—as well as by responsible leaders in business and government—as not just a good idea but an urgent imperative.
Among the best near-term solutions are concentrated solar power, geothermal power, and wind power. Now, however, a new idea is coming forward that might allow the third one—wind power—to really take off.
Bay area inventor and technology entrepreneur Saul Griffith envisions a wind-powered future. He’s helped design light, cheap, and efficient wind turbines mounted on kites. They harness energy from high-altitude wind currents and send it zapping earthward through cables. . .
With venture funding from Google, his Alameda, Calif.-based company, Makani Power Inc., has built prototypes of these airborne turbines and routinely tests them in Maui, Hawaii (“Makani” is the Hawaiian word for “wind”). On the ground, the contraptions look like large swept-wing kites fitted with compact three-bladed turbines. Aloft, they sweep in wide circles, hunting the best winds, either high up or close to the ground. Making kite-mounted power plants requires only off-the-shelf technology, and the physics is straightforward. The same wind that flows over a wing to keep the kite aloft can be captured as energy by wing-mounted turbines.
How much energy—all renewable, naturally—could be generated this way?
In the United States alone, wind maps show that the potential for energy generation is in the range of 8,000 gigawatts. That’s equivalent to 8,000 modern coal-fired energy plants. But the wind’s most potent energy is out of reach for traditional ground-mounted turbines because it whips back and forth at altitudes of 500 meters to 15,000 meters. Griffith calculated that a kite turbine 10 kilometers high will capture nine times more energy than a pole-mounted turbine spinning 100 meters off the ground. . .
Proponents of high-altitude wind power claim that tapping just 1 percent of its potential could power everything on Earth.
Compared with their ground-mounted cousins, kite-mounted turbines are cheaper and lighter: a 1-ton wing, and 3 tons for the whole system, compared with 100 tons of concrete and steel. The kites make less noise and kill fewer birds. And they’re more efficient, said Griffith. A traditional tower turbine spins at capacity 30 percent of the time. But wing-mounted units, with access to higher consistent wind speeds, turn out peak megawatts up to 65 percent of the time.
This looks quite promising. It’s the kind of thing that to IEET seems like a no-brainer to support for further investment and exploration. Ethically, we must begin finding ways to avoid passing the cost of our generation’s excesses onto the next generation. Emerging technologies like high-altitude wind power are a win-win.
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