The wind blowing through the streets of Manhattan couldnâ€™t power the city, but wind machines placed thousands of feet above the city theoretically could.
The first rigorous, worldwide study of high-altitude wind power estimates that there is enough wind energy at altitudes of about 1,600 to 40,000 feet to meet global electricity demand a hundred times over.
The very best ground-based wind sites have a wind-power density of less than 1 kilowatt per square meter of area swept. Up near the jet stream above New York, the wind power density can reach 16 kilowatts per square meter. The air up there is a vast potential reservoir of energy, if its intermittency can be overcome.
Even better, the best high-altitude wind-power resources match up with highly populated areas including North Americaâ€™s Eastern Seaboard and Chinaâ€™s coastline.
"The resource is really, really phenomenal," said Christine Archer of Cal State University-Chico, who co-authored a paper on the work published in the open-access journal Energies."There is a lot of energy up there, but itâ€™s not as steady as we thought. Itâ€™s not going to be the silver bullet that will solve all of our energy problems, but it will have a role."
For centuries, weâ€™ve been using high-density fossil fuels, but peaking oil supplies and climate concerns have given new life to green technologies. Unfortunately, renewable energy is generally diffuse, meaning you need to cover a lot of area to get the energy you want. So engineers look for renewable resources that are as dense as possible. On that score, high-altitude wind looks very promising.