Using Artificial Tornadoes to Generate Electricity?

September 19, 2008

First, a shout-out to reader Jim Rowing, who responded to my recent blog about whether scientists should try to manipulate hurricanes to lessen their destructive force with this comment:

Why not harness the energy! The east coast from NC to FL and the Gulf Coast could become the greatest power producing plants in the country.

Now, trying to harness the power of hurricanes might seem like a truly outlandish notion, but consider this: According to the Web site of the National Oceanic and Atmospheric Administration, in a single day a hurricane can release an amount of energy equivalent to one-half of the world’s entire electric-generating capacity. Moreover, as another reader pointed out, NOAA meteorologist Neal Dorst actually seems to have given at least some thought to the idea:

If someone can figure out a way to harness that energy, the more power to them. They could earn millions of dollars and the gratitude of everyone on the shore. Every dyne of energy harvested would be one less dyne blowing over trees.

The biggest technical impediment is that a hurricane's energy is low grade. It's abundant, but it's spread over a tremendous area. For energy to be high grade it should be concentrated, making it easy to gather and use. You would need a field of wind turbines covering dozens of square miles in order for it to be profitable. And it would have to be mobile, so you could intercept landfalling storms, or chase those that change direction. Of course, you have to expend energy to move them around, so you run the risk of losing money on the operation. The same is true of wave turbines plus you would need to find a way of anchoring them securely without compromising mobility.

It would be a daunting technical task, plus you have to worry about your turbines being robust enough to sustain damage from windblown debris and be able to transmit the energy gathered quickly. So after you draw up your engineering specs, you'd better have an investor or two, because it will cost you a great deal of money to build so many of these reinforced, mobile turbine units even before you collect you first erg. has proposed the idea of creating artificial hurricanes — well, hurricane-sized tornadoes, actually — and then harnessing them for electricity generation.

But here’s another intriguing variation on the concept. Canadian engineer Louis Michaud has proposed the idea of creating artificial hurricanes — well, hurricane-sized tornadoes, actually — and then harnessing them for electricity generation. A 2005 article in The Economist explains the basic concept of what he calls the atmospheric vortex engine:

His idea works on a similar principle to a solar chimney, which consists of a tall, hollow cylinder surrounded by a large greenhouse. The sun heats the air in the greenhouse, and the hot air rises. But its only escape route is via the chimney. A turbine at the base of the chimney generates electricity as the air rushes by. A small solar chimney was operated successfully in Spain in the 1980s, and EnviroMission, an Australian firm, is planning to build a 1,000-meter-high example in New South Wales. But the efficiency of such a system is proportional to the height of the chimney, notes Mr Michaud, which is limited by practical considerations. His scheme replaces the chimney with a tornado-like vortex of spinning air, which could extend several kilometers into the atmosphere.

This vortex would be produced inside a large cylindrical wall, 200 meters in diameter and 100 meters tall. Warm air at ground level enters via tangential inlets around the base of the wall. Steam is also injected to get the vortex started. Once established, the heat content of the air at ground level is enough to keep the vortex going. As the air rises, it expands and cools, and water vapor condenses, releasing even more heat. This is, in fact, what powers a hurricane, which can be thought of as a heat engine that takes in warm, humid air at its base, releases cold, watery air at the top of the troposphere, about 12 kilometers up, and liberates a vast amount of energy in the process. (Just as water requires heat to make it boil, it releases heat as it condenses back into a liquid.)

Mr Michaud's vortex would reach a similar height to that of a hurricane, but its base would remain stationary. The intensity of the vortex would be controlled by closing the inlets around the base, or by opening another set of inlets to inject air in the opposite direction and so slow the vortex's rotation. And, of course, there would be a set of turbines at the base of the vortex that would allow its energy to be harnessed as air rushed through the inlets. Mr Michaud estimates that an atmospheric vortex engine with a diameter of 200 meters would produce around 200 megawatts of power.

Some people may find the idea of creating artificial tornadoes a bit, well, off-putting, due to the potential destructiveness of such a storm if it were to spin out of control. But on his Web site, Michaud argues that artificially generating tornadoes might actually help protect us against natural ones, by relieving atmospheric instability. He adds:

A small tornado firmly anchored over a strongly built station would not be a hazard. The AVE [Atmospheric Vortex Engine] could increase the power output of a thermal power plant by 30 percent by converting 20 percent of its waste heat to work.

It is estimated that it would be possible to establish a self-sustaining vortex to demonstrate the feasibility of the process with a station 30 meters in diameter under ideal conditions. Learning to control large vortices under less than ideal conditions would be a major engineering challenge. Developing the process will require determination, engineering resources; and cooperation between engineers and atmospheric scientists. There will be difficulties to overcome, but they should be no greater than in other large technical enterprises.

EcoGeek reports that since Michaud first unveiled his idea,

Progress has also been made in trying to work out how to control the Tornadoes (or, as Michaud has re-named them "atmospheric engines") in case peculiar weather starts to make them self-sustaining or threatens to move them outside of the a controlled area. Turning off the heat from the power plant might do it, but the air supply could also be limited using a large wall that would surround the tornado. Dousing the area with cold water could also be an effective failsafe...cooling the ground and thus shutting down the temperature gradient from the ground to the sky.

EcoGeek estimates — though I’m not sure exactly where they get the numbers — that tornado-powered plants could replace 40 percent of the generating capacity currently fueled by burning coal, a major source of those evil greenhouse gas emissions that are a leading cause of global warming.

So, what do you think? Should we give Michaud’s idea a try, or is the idea of creating artificial tornadoes all over the nation a bit too scary? Express your opinion below.

Photo: iStock

Comments

[Mothra]

In light of all the other kinds of energy, they all have potential risks and problems. Even wind turbines cause problems for birds. If it was able to be controlled and contained without causing some kind of destruction, great. It would be renewable and it wouldn't require any kind of fuel. But certainly, it could be dangerous if it got out of control. Also, what would the noise level be like? It's worth looking into.

[DC Sybil 88]

I think this is a very creative idea. Naturally, scientists would have to take precautions for safety, but if you look at the damage we are doing to the environment from burning coal, I think the benefit outweighs the risk.

[Louis Michaud]

Mechanical energy is produced when warn or humid air rises. I propose using an artificial tornado and not a hurricane to capture this energy. An Atmospheric Vortex Engine (AVE) could look like an open roof round arena with a small tornado firmly anchored at its centre. The tornado could be 30 m in diameter at its base and could extend to a height of several kilometers.

The heat source can be solar energy or waste industrial heat. The solar heat can come from warm sea water or simply from warm humid air. There is no need for solar collector; the solar collector is the earth’s surface in its unaltered state. The atmosphere is heated from the bottom by solar radiation and cooled from the top by infrared radiation to space.

The vortex engine has the same basis as the proven solar chimney. The physical tube of the solar chimney is replaced with centrifugal force in the vortex. A chimney prevents rising air from being diluted by cooler ambient air. The solar collector is replaced with heat exchangers or by simply drawing in warm humid ambient air.

The pressure at the base of a chimney is less than the surrounding pressure because of the buoyancy of the rising warm air. The pressure difference is used to drive turbines located around the periphery of the station. The turbines need not be directly in the vortex.

An AVE power station could have a diameter of 200 m and generate 200 MW of electrical power. The vortex could have a diameter of 30 m at the base and could extend to a height of up to 15 km. There could be 20 turbines around the periphery of a vortex engine with a power output of 10 MW each.

The vortex engine would alleviate global warming by reducing the quantity of fuel required to meet energy needs. The AVE could remediate global warming by lifting heat above greenhouse gasses from where it can more easily radiate to space.

Vortex engines would increase the efficiency of thermal power plants by reducing the cold sink temperature from +20°C at the bottom of the atmosphere to -60°C at the top of the troposphere.

A presentation on the process and its thermodynamic basis is available at:
http://vortexengine.ca/misc/Thermo_Pop.pdf
There is more information available on the above web site.

AVEtec built a working 1 m diameter working model in 2006 and tested a 4 m diameter prototype in 2008. There is a strong convergence of evidence for the scientific basis of the AVE. Process engineering experience can provide new tools for the study of the atmosphere including: ideal thermodynamic cycles, expanders, and numerous convection processes.

[Tyrone]

I think Michaud has a really incredibly great idea, and I think we should start building a full-scale vortex engine immediately!

[Astroboy]

That would be WILD to have a hurricane on a leash like that.

[Janet]

I still don't understand what keeps the artifical tornado from flying out of control.

[John Brisker]

I have to say that of all the alternative energy proposals that I've seen, this is probably the most imaginative.

[McCain for President]

This scheme doesn't even sound remotely practical. The only answer to the energy crisis is to increase domestic production. DRILL, BABY, DRILL!!!!

[Sierra Club member]

That's precisely how we got to the verge of environmental catastrophe. We need to stop using oil and coal (unless we can find a way to sequester the carbon emissions). But I'd rather see more conventional wind farms rather that this proposal, and more deployment of solar panels, along with aggressive efforts to increase our energy efficiency and reduce consumption. It's already been proven that we could reduce our energy use significantly and still have a good standard of living.

OBAMA BIDEN 08--VOTE FOR PROGRESS!

[Vote for Innovation]

Supplying the energy needs of a modern city using solar panels or wind farms would require an area 100 to 1,000 times the area of the city. With solar panels the area becomes unavailable for other uses such as farming. With wind turbines a city of 100,000 inhabitants could require 1,000 large wind turbines. The atmospheric vortex engine would use the earth’s surface in its unaltered state as the heat collector. The footprint of an AVE would be no larger than the footprint of a thermal power plant of the same capacity. Normal land use would be unaffected.

[Ed Aggazio]

I like the idea, But can you imagine what that would look like from outer space? Especially if there are AVE's on every continent?

[Ron]

Good point...that would be a pretty strange sight from space. Then again, so are Martian dust storms.

[Morteza Rafei]

I think at first we have to absorb a real typhoon in a specified place, that is possible by using the concepts of limit cycles. Then, by using a special form of helix wind turbines, we can easily generate electricity.