[wigiv]

I balked at first glance because "free energy," but here we have a unique method for turning thermal into kinetic energy. Slightly outside the bounding box of this energy system, of course, lies the expending of more energy than what's produced to keep the hot water hot and the cold water cold.

But using natural low-grade temperature differentials as the author suggests, what might this arrangement achieve that a Stirling engine doesn't? More torque? Advantage of fewer moving parts? Novelty only?

[amluto]

Wikipedia claims that one of the problems of Stirling engines is that they depend on the rate at which heat can be transferred to a gas. A Nitinol engine has a metal as its working object (functionally like a working fluid, just not actually fluid), so the thermal conductivity could be considerably better. The result could plausibly be higher power for a given amount of metal in use.

[imode]

We already have this unique method via Nichrome wire. You can see a really neat application of this in a common toaster here: https://www.youtube.com/watch?v=1OfxlSG6q5Y

[dirktheman]

Technology Connections is my favorite YouTube channel. He's just so good in explaining the technological intricacies of everyday things, and his humor is so wonderfully snarky. I highly recommend turning on the subtitles as well, he puts a lot of effort in them.

[greypowerOz]

"oh, god... he has a third one"

excellent writing and delivery, and yes, usually an easter egg or two in the CC ;)

[GuB-42]

Yes, I wonder why "free energy". It is not free energy, it is a respectable, thermodynamic law abiding machine.

According to what I've seen here, it is good for making tiny engines but the efficiency is low.