Here is a bit more information on how the physics work behind this device from wikipedia:

Thermoacoustic engines (sometimes called “TA engines”) are thermoacoustic devices which use high-amplitude sound waves to pump heat from one place to another, or conversely use a heat difference to induce high-amplitude sound waves. In general, thermoacoustic engines can be divided into standing wave and travelling wave devices. These two types of thermoacoustics devices can again be divided into two thermodynamic classes, a prime mover (or simply heat engine), and a heat pump. The prime mover creates work using heat, whereas a heat pump creates or moves heat using work. 

The fact that this guy generates the heat from solar power is even more clever.

How do you even think of this?  We hope you enjoy the video and if you can think of any practical uses for this thing feel free to comment.