This is the world’s first solar powered 3D printed Stirling engine. Let me repeat. A 3D solar powered Stirling engine! Now that is cool off grid tech. This little ingenious device isn’t going to power your home just yet, but it is a proof of concept, and it works. The mirrors reflect the Sun’s energy onto the central area which heats up causing expansion and as the air cools it contracts. This 3d printed concept was created by German aeronautical engineer Andreas Haeuser.