Power Generation With Nanotubes

NubKnacker writes "Business World is carrying an article about how an Indian scientiest at IIT, Bangalore has come up with a new innovative method to produce power by blowing gases over carbon nanotubes. The underlying physics of the idea is quite simple yet no one had thought of it until today."

Comments

Cost prohibitive for non-sensing applications

[ToshiroOC]

Unfortunately, nanotubes are still so expensive, velocity sensors are probably all these would be good for - larger power generating variants would be cost prohibitive. I also wonder how robust any velocity sensor made with nanotubes could be; sure, you could probably put one in a steam pipe or a LNG line and get reasonable data (in fact, in any nanotube-friendly chemical you could probably get good data from this sensor), but if you wanted to put one on the outside of a car or an airplane for velocity measurements, I can see nanotubes being easily damaged; either pulled from their moorings/leads in the device or simply snapped - nanotubes may be strong, but that's not going to help if you have a 500mph tiny sharp projectile impact just a few nanotubes. Also, in 'dirty' environments such as those outside of a car or a plane, you would probably start getting buildup of different pollutions at a reasonable rate, causing a need for either a) constant recalibration or b) sensor replacement.

How was this "unknown"?

[RealErmine]

According to this the Seebeck Effect (current flow from temperature difference) is just the reverse of the Peltier Effect (temperature difference from current flow). It's been known that the semiconductor material of a Thermoelectric cooler (or Peltier cooler) works in reverse, generating current from a temperature difference between sides. The story seems to imply that this is a new discovery both for nanotubes and other semiconductors and it's been known that nanotubes can act as semiconductors. It does not exlplain how doing this with a wire and a moving gas is new.

Re:How was this "unknown"?

[Randolpho]

It's not "unknown", it's just "undone" before. It's been known that you could get a current by creating a temperature differentiation on both wires and nanotubes. It's just that nobody had ever tried to create a temperature difference through the Bernoulli Principle. Nobody did it before this guy, the guy deserves credit for it for thinking of it first, even though it seems so damn obvious to us now.

Think of it this way:

We knew about peanutbutter. We knew about chocolate. We knew they both taste good. But we didn't know they tasted so damn good together until they came out with Reese's Peanutbutter Cups. Thank you Mr. Reese, whomever you are. ;)

Re:Very cool, related story in Nature

[Anonymous Coward]

Kind of like an afterburner on the power plant...these could be placed inline after the turbines and generate an extra kick.

Except in order to generate power the wires have to put a drag on the gas flow. That drag puts drag on the turbines and probably costs more than it produces.

Re:Very cool, related story in Nature

[arete]

probably not.

Mechanical work (wind-power, hydroelectric, bicycle generator, regenerative braking) is already a low-entropy source... it's easy to capture it, and while it can't be lossless we have techniques that can generally come pretty close to the theoretical values for capturing it.

(which doesn't mean it can't be better, lighter, cheaper - but they're basically pretty good)

A pressure differential is somewhat worse - and a heat source (solar heating, gasoline, diesel, natural gas, coal, heating oil...) is very high entropy and very hard to get the energy out of.

Usually we use the heat source to generate a pressure differential that generates mechanical work. (which may or may not then generate electricity)

So that's more likely where this is applied - where you have a heat source that can be used to create a pressure differential.

Arete