From the Carnegie Institution , some lofty ideas. Would you imagine a steady energy supply coming from high altitude kites?
Enough wind to power global energy demand
Washington, D.C.— There is enough energy available in winds to meet all of the world’s demand. Atmospheric turbines that convert steadier and faster high-altitude winds into energy could generate even more power than ground- and ocean-based units. New research from Carnegie’s Ken Caldeira examines the limits of the amount of power that could be harvested from winds, as well as the effects high-altitude wind power could have on the climate as a whole. Their work is published September 9 by Nature Climate Change.
Led by Kate Marvel of Lawrence Livermore National Laboratory, who began this research at Carnegie, the team used models to quantify the amount of power that could be generated from both surface and atmospheric winds. Surface winds were defined as those that can be accessed by turbines supported by towers on land or rising out of the sea. High-altitude winds were defined as those that can be accessed by technology merging turbines and kites. The study looked only at the geophysical limitations of these techniques, not technical or economic factors.
Turbines create drag, or resistance, which removes momentum from the winds and tends to slow them. As the number of wind turbines increase, the amount of energy that is extracted increases. But at some point, the winds would be slowed so much that adding more turbines will not generate more electricity. This study focused on finding the point at which energy extraction is highest.
Using models, the team was able to determine that more than 400 terrawatts of power could be extracted from surface winds and more than 1,800 terrawatts could be generated by winds extracted throughout the atmosphere.
Today, civilization uses about 18 TW of power. Near-surface winds could provide more than 20 times today’s global power demand and wind turbines on kites could potentially capture 100 times the current global power demand.
At maximum levels of power extraction, there would be substantial climate effects to wind harvesting. But the study found that the climate effects of extracting wind energy at the level of current global demand would be small, as long as the turbines were spread out and not clustered in just a few regions. At the level of global energy demand, wind turbines might affect surface temperatures by about 0.1 degree Celsius and affect precipitation by about 1%. Overall, the environmental impacts would not be substantial.
“Looking at the big picture, it is more likely that economic, technological or political factors will determine the growth of wind power around the world, rather than geophysical limitations,” Caldeira said.
According to legend/folklore, there is a big hole in the ground, somewhere around Spokane Washington; out in the boonies. It’s like a large well, and it is deep. The locasl who know of it, toss all their junk down there; dead cows, refrigerators, whatever. Supposedly, you never hear a sound of anything hitting the bottom, it’s way to deep. Mel’s hole, it is called.
And this Mel chap who used to own it, tried to measure the depth, by dropping a fishing line down there with a weight on it, to see when it hit the bottom. He used 20# test mono nylon, and a one pound lead weight. He set up a plank across the well and a pulley so he could let the line go down the hole. He bought the line in 2 pound spools, and tied them onto the existing line, and then payed that out. Accordfing to Mel reporting this story, he had put at least 20 spools of line down that hole and he still hadn’t reached the bottom; the line just kept on going out and down the hole and the lead weight never did hit the bottom.
Do you know, that neither the talk show host nor the onsite reporter telling of this, or Mel himself, not to mention even one of the callers to the radio station, ever cottoned on to the fact that with over 40 pounds of line sent down that hole, the string would have broken long ago. Clearly the lead was down the hole on something, and the sheer weight of the long string was more than enough to keep the string taught, and continuing to go down the hole.
Mel eventually sold the hole to some investors apparently, and moved to Australia. He hasn’t been heard from since; and apparently they still toss the dead cows down there, and sometimes an old jalopy. The locals don’t let on where the whole is in case the place got vandalized.
LOOK ! ! ! Up in the sky ! ! ! It’s a bird ! ! ! It’s a plane ! ! !
NO ! ! ! IT’S FREE GREEN PIE IN THE SKY ! ! !
[another Marvel moment….and Makani is heavily funded by DOE & NSA front groups]
Fair amount of comments. First of all, I don’t think either kites or sky wind turbines are unfeasable. They simply will have a huge impact on local weather and regional climate. If you put up a system that captures wind over thousands of square kilometers of vertical airspace, you will have unintended consequenses.
Rob L.
“In article they state worldwide wind power 1800TW, extracting a few TW is not going to be a problem for climate, and at 10km altitude won’t even notice it at ground level – whereas thermal power stations do produce noticeable local effects.”
I think you have it backwards there. The jet stream is critical to all weather. Were it is at any moment, the weather on either side of it can be dramatically different. High pressure and low pressure systems are guided by it.
Were I live, it makes the difference between sunshine and rain. You slow it down, what happens? no one knows. The impact would be far beyond the extracted energy. It would be caused by the slowing down of the wind and built up of moisture. Think what happens infront of mountain ranges, rain falls. A large number of these would have a huge impact. As I said in my simple equation, 2800 Square Kilometers blocked and the wind cut in half. That is massive.
Falstaff says
“During any given daylight hour in the US there are some three thousand large body jet aircraft 3-5 miles up. Has this altered the weather?”
Well maybe their exhausts. Otherwise not much, they occupy any spot only for a fraction of a second. They go in every which direction, back and forth between airports. They are not stationary. However, they leave a trail behind when going through clouds, that is quite obvious.
Kites, or airborn turbines, are stationary, they take energy out of the wind, slowing it down over the same area, year after year, decade after decade. Just like a tall building or a mountain.
tty
“Umm … At 30,000 feet and -40 centigrade the density of air is about 0,45 kgm-3. To produce 10 kW per square meter would require a wind strength of about 210 m/s or about 450 mph”
I am only quoting the article I referenced. However if there is less energy up there, then wind wall would be even bigger. Ouch!
Interesting to note that “flying a kite” is a political phrase use to describe releasing a policy suggestion to see if the public are stupid enough to swallow it.
Hey!….. I’ve got this radical idea for power generation.
….. We take this black stuff, coal I think it’s called, and….. wait for it…..wait for it, this is the really radical part……. We burn it to produce heat, to boil water, to create steam, to spin a turbine so as to generate electricity!!!!!
….. BOOOYAHHHH!!!! Who’s ya daddy…. How’s them little orginal apples, ‘eh…?. And apparently coal costs peanuts!
Man. What’s not to like about this???
30,000 ft, how high is Mt Everest? there are calm days on Mt Everest, what happens to kites on a calm day?
And won’t it be fun when the cable breaks near ground level and we have a high voltage line dragging across a city.
I’d seen something simiular some years ago, perhaps in New Scientist (can’t find the ref right now). It doesn’t seem nutty to me, this is where a good proportion of the energy from the Sun could be harvested. Technical and technological problems? Of course there are. But, to the various knee-jerk nay sayers in this thread: what, nuclear, for example? ‘Watch-making by the ton?’ What if there’s a loss-of-coolant accident? What if the sodium coolant of breeder reactors is released? What if someone seriously unwise gets hold of fissile material? I don’t think the consequences of a failure in a well-designed, in engineering terms, system of high-atmosphere wind energy would be so disastrous as an equivalent failure in nuclear. All technologies, of whatever type, involve risks as well as benefits.
As usual, the issue of whether there’s enough wind energy is irrelevant – there’s enough of all kinds of energy (wave, solar, hydro, etc) to meet all our needs. The issue is costs, and I mean total costs, not the fraudulent cost analyses that have been provided by energy source advocates. The wind is variable and therefore not reliable, regardless of where the wind is found.
Unreliable power sources means a need to duplicate capacities to back up wind power, which means duplicating costs. Thus wind energy is junk energy, and pollutes the grid. End of story.