Power From the Gulf
A couple weeks ago, I speculated about the possibility of using warm water in the Gulf of Mexico as a power source. There's a lot of energy in there, but it isn't obvious how to tap it. The first idea which comes to mind is somehow building a chimney thousands of feet high to get power from atmospheric convection. As warm air rises through the chimney, the atmospheric instability of the heat and humidity at ground level would create a lot of suction at ground level. This suction can be used to drive turbines and generate power.
The problem is that constructing such a beast would be an engineering nightmare, especially in a hurricane-prone region. To my knowledge, nobody has built a structure more than 5,000 feet high of any sort (the tallest manmade structures are broadcast antennas), much less a chimney which has to have a significant diameter and hence be susceptible to high winds.
Well, it turns out that someone else has a clever idea for getting around this problem. Tipped off by an article in The Economist, I learned about something the inventor dubs the Atmospheric Vortex Engine.
Apparently the inventor has been flogging this idea for years without much success in attracting backers or building a large-scale proof-of-concept. Normally that would trigger my Crackpot Alarm. But in this case, the idea is actually quite clever, and might even work.
In a nutshell, the Atmospheric Vortex Engine would create a giant vortex of air to effectively provide a chimney much higher than could be built out of bricks and mortar--possibly even reaching up to the bottom of the stratosphere. The claim is that a structure 200m in diameter and 100m high could create a vortex which would maintain its integrity through the entire troposphere.
The result would look something like a giant tornado anchored at the vortex station on the ground, and topped by a big cloud. Unlike an actual tornado, this artificial vortex wouldn't be destructive since it could never separate from the ground station and damage ground structures: without the ground station to provide the angular momentum to the rising column of air, the vortex would quickly dissipate.
(As an aside: the inventor suggests mechanisms for shutting off the vortex if needed, including injecting counterrotating air into the station. I suspect this will be unnecessary, though, since all that would be needed is to close the air inlets in the ground station. Without some source of rotating air, the vortex has nothing to sustain itself, and will disappear from the base upward.)
But there are some significant unanswered questions before we'll know if this clever idea would work in practice.
The biggest one is how fast does the air need to be spinning at ground level in order to maintain the vortex high into the atmosphere? As the vortex climbs, it also gets wider and slower, and at some point will dissipate in the natural atmospheric turbulence and wind shear. I suspect that in order to maintain the vortex at over 10,000 feet in reasonable atmospheric conditions will require a hellacious velocity at ground level--possibly on par with powerful tornadoes (300+ MPH).
Another concern is whether the vortex might spontaneously detach itself from the ground station. This could be because of wind conditions, or if it turns out that the attachment at the base of the vortex is inherently unstable. This probably wouldn't create much of a hazard (the detached vortex would dissipate before too long), but frequent detachment events would ruin the efficiency of the power station.
If the Atmospheric Vortex Engine works, it would have the interesting side-effect of creating a semi-permanent raincloud downwind of the station. This would dramatically change the microclimate, probably leading to frequent rainshowers, but possibly reducing the number of big storms (since the engine would be gradually dissipating atmospheric instability). Aircraft would also have to be kept out of the area, since the vortex would be a clear hazard, especially at lower altitudes where the wind velocity would be highest.
I'll be very interested to see if anyone can build a pilot project large enough to demonstrate if this thing would actually work.