Solar powered low temperature twin cylinder Stirling engine, shown running on sunlight.

As well as being transparent to visible light acrylic is transparent to infra-red. This allows the heat from the sun to pass straight through the top plate and directly warm the air inside the top of the chambers.

The top of the displacers are painted black to aid in heat capture.

The engine will also operate on the heat given from a halogen or incandescent light, as well as the human hand, hot coffee, ice etc.