CoopIP index

Prospecting for SuperWind

Ken Caldeira and Cristina Archer's famous estimates put global wind energy at some hundred-plus times greater than human needs. Given such abundance, its smart to cherry-pick the very finest wind by availability, reliability and strength. Call this "superwind". Let it be defined as either regularly occurring gale to hurricane strength wind as found in jet streams (particularly at upper altitudes), gap wind, convection tails, katabalic wind, etc., or extremely reliable or persistent wind, such as sea breeze and stratospheric return flow.

The common theme to most superwind is energy focusing. Many planetary features, like spin and differential heating on the grand scale, and coasts and mountains on a more mesoscale, focus wind energy into vortices and jets. Vortices have a zone between center and margin where flow is most energetic. Jets have cores where energy focuses. Chasing superwind is envisioned in some conceptions. The jet stream might be somehow followed cross country to extend capacity factor close to 100%.  Every little cumulus has an convection tail, like an invisible stalk of a mushroom cloud, where energy focuses as a vertical jet (pure lift).

Mountain ranges have major focusing or blocking effects on wind. A mountain wave is the piling up of air pressure to windward as a bow-wave that often extends to the stratosphere. Wind tends to go around mountain bow waves or through gaps accelerated. Wind jumping over continental land masses accelerates katabatically as it flows downhill on the lee-side. Look at a global average wind map to clearly see these effects (Joby Energy has a good graphic online).

Of course superwind alone is not financially attractive without a market. Fortunately many of the best geographically accelerated upper winds occur over major energy markets like Japan and the upper US East Coast. Remote superwind development will lag behind local superwind harvesting and as the (liquid) hydrogen economy matures. There are precedents, like early Niagara Falls hydropower, where "build it and they will come" applies.

KiteLab located on the US NW Pacific Coast to do AWE research, as the year-around winds in this area are perhaps the best in the country. It was Wayne German (SoarEn Consulting) who touted this opportunity. WindLift  relocated to Kitty Hawk, North Carolina; and Makani Power jets to Maui, Hawaii, by the same logic. A company serious about developing AWE must go where the resource is plentiful to get the most flying time in. Avoid the many lesser "dead" zones unless, perhaps, you aim for marginal low wind markets with specialized ultralight (UL) technology.

CoopIP                                    ds

There is no fault in your cautious logic, but the siren song of high superwind is impossible for the true HAWP crowd especially to resist.

Conventional wind power is indeed now economic in the wealthier energy markets, but its not so cheap. High capital cost has slowed & even prevented its implementation for most of the planet. Kites promise a much lower price of admission to green power, even in ideal ground turbine territory.

Trouble with low wind and kites is more frequent landing and relaunching, or more towing, helium, etc.   A conventional turbine sits out calm without fuss.  For near baseload availability it may be better to routinely furl AWE in high wind than force it to land all the time in slower wind. There is also the need to extract considerable power just to keep a kite aloft.  Low winds are very tough to get net output.   I have held 2300 sq ft of Osborne parafoil with one hand in light air; it had nothing more to give. Naturally the lightest kite tech wins in low wind (as well as key safety-critical/insurability factor), so KiteLab kind of owns lowest windspeed AWE practice.

The fascination with high winds is similar to gold, which nowadays mostly comes from industrial processing of low-grade ore.  Many of us are suckers for big gold nuggets in this pioneering phase. KiteLab has flown extensively in hurricane force winds on the NW coast to develop high wind kiting; it is doable and quite a thrill, but you better like long tails. A tiny kite gone nuts in high wind will pull a strong man down.  Note that "superwind" was broadly defined to include slower but highly reliable wind, like stratospheric return flow.

I hope AWE wins across the board, high-and-low wind, and windmills become mostly historical displays, like Old Holland.  This potentially means far less embodied environmental impact and more human prosperity.  Many wind farm regions are near saturation already, and each turbine entails a service road, concrete foundation, tons of steel tower, and a degraded natural appearance. Offshore surface turbines have their own problems.  The sky is far more ample wind power real-estate and the denser resource.


Note:  I forgot to mention "crack" wind previously, where multiple factors combine into superwind, like Hung Vu's tradewind and seabreeze added together (drooling on keyboard).